Genus Aphis

Adult apterae of Aphis acetosae in life (see first picture below) are black or very dark bluish green. Tibiae are pale with dark apices, and siphunculi and cauda are black. The antennae are pale, but the segments I, II, V & VI and the apex of IV are dark. The antennae are 0.6-0.7 times the body, with the terminal process 1.8-3.2 times the base of antennal segment VI. Secondary rhinaria are absent, and the longest hair on segment III is 1.0-1.6 times the basal diameter of that segment (cf. Aphis rumicivora, mainly on Rumex acetosella, which has the longest hair 0.3-0.7 times basal diameter). The rostrum reaches behind the hind coxae, with the apical rostral segment 1.0-1.1 times the second hind tarsal segment. The abdominal dorsum has broad, heavily pigmented, reticulate, more-or-less fused cross bars (see second picture below), occasionally fused into a carapace, and marginal sclerites. The abdomen has marginal tubercles on segment I-IV, and VII (sometimes also V & VI); those on segment VII being large, similar in basal diameter to the siphunculi at midlength (cf. Aphis rumicis, where the marginal tubercle on segment VII has a basal diameter much less than that of siphunculi at midlength). Siphunculi are rough, 0.12-0.19 times the body and 1.25-1.65 times the cauda. The cauda has 11-19 hairs (cf. Aphis craccivora, which has 4-9 hairs on the cauda). Body length of adult Aphis acetosae apterae is 1.6-2.7 mm.

Adult apterae of Aphis achyranthi are dull yellow or yellowish brown. The siphunculi and cauda are dark brown, apart from right at their bases (cf. Aphis nasturtii, Aphis gossypii & Aphis glycines, which have the cauda pale or dusky). The antennae are 6-segmented, 0.5-0.7 times the body, with the terminal process 2.0-2.5 times as long as the base of antennal segment VI. The hairs on antennal segment III are about as long as, or a little longer than, the basal diameter of the segment. The rostrum reaches the third pair of coxae, with the apical rostral segment as long as, or a little longer than, the second hind tarsal segment. The hind tibiae are markedly curved, with rather long hairs. The abdominal dorsum is without an extensive dark sclerotic patch (cf. Aphis craccivora, which has an extensive dark sclerotic patch). Postsiphuncular sclerites are present. The longest hair on the anterior abdominal tergites is about 1.0-1.3 times the basal diameter of antennal segment III. Abdominal tergite VIII has 5-6 hairs (cf. Aphis spiraecola, which usually has only 2 hairs on tergite VIII). The siphunculi are 0.08-0.12 times body, and 1.0-1.3 times the cauda. The cauda has 9-10 hairs. Body length of adult Aphis achyranthi apterae is 1.6-2.5 mm.

First image above by permission, copyright Sunil Joshi & Poorani, J. Aphids of Karnataka (accessed 12/2/20).
Second image copyright Krzysztof Ziarnek, Kenraiz under a Creative Commons License.

Adult apterae of Aphis agastachyos (see picture below of adult aptera with immatures) are oval shiny dark green, with no dorsal abdominal sclerotization. Their antennae are evenly pale or with darker apices, 0.5-0.6 times the body length. The antennal terminal process is 1.5-1.8 times the length of the base of antennal segment VI. The hairs on antennal segment III vary from blunt to very acute with the longest about 1.5 to 2.0 times as long as the basal diameter of the segment. The apical rostral segment (RIV+V) is about 1.25 times the length of the second hind tarsal segment (HTII) and has 4-8 accessory hairs. There are large marginal tubercles on abdominal tergites I and VII, bluntly conical, about as tall as their basal width. The legs are pale or (in alatiform specimens ?) with dark apices to the femora and tibiae. The siphunculi are pale, or dusky towards the tips, rather thick, evenly tapering to near the apex, with a wide flange and 1.4-2.0 (1.1-1.6 in Blackman) times the caudal length (cf. Eucarazzia elegans, which has the siphunculi strongly swollen and 5.4-8.2 times as long as the cauda). The cauda is darker than the siphunculi, thick, more or less bluntly triangular with 7-12 strongly curved hairs.

Image above copyright Andrew Jensen under a cc by-nc-sa licence.

Adult apterae of Aphis alienus (see first picture below for probable Aphis alienus) are apple green to dark green with little or no wax, dark siphunculi and a dusky cauda. The antennae are (5-)6 segmented, with the fifth segment dusky at the apex and the sixth darker; they are shorter than the body, with the terminal process 2.0-2.7 times the base of segment VI. The longest hair on antennal segment III is 0.58-0.83 times the basal diameter of that segment. The apical rostral segment (RIV+V) is 1.18-1.63 times the second tarsal segment (HTII) and 1.14-1.79 times the base of antennal segment VI (cf. Aphis gossypii / Aphis frangulae, where RIV+V is only 0.85-1.22 times the base of segment VI). The dorsal abdominal sclerotic pattern is either absent, or limited to dusky bands across tergites VII- VIII. Marginal tubercles on tergites I & VII are fairly conspicuous; those on tergites II-VI are either absent, or smaller and more rounded. Siphunculi are 1.11-1.88 times the cauda. The body length of adult Aphis alienus apterae is 0.99-1.76 mm.

The adult apterae of Aphis armata are black, rarely with any white wax spots (se first picture below). The middle abdominal tergites in apterae are usually without dark sclerotic bands, but they may have a few scattered sclerites, and the largest apterae may have segmental bands. The longest hairs on the hind femora and the tibiae are about twice as long as the least width of the tibiae. The ratio of the length of the apical rostral segment (RIV+V) to the length of the second hind tarsal segment is 1.04-1.25 (cf. Aphis fabae fabae for which this ratio is 0.88-1.10). The body length of Aphis armata apterae is 2.2-2.9 mm. Immatures often have discrete wax spots.

Adult apterae of Aphis asclepiadis on their primary host, dogwood (Cornus), in spring, are dark yellow to green - with their siphunculi variably coloured from green to black. Apterae on the secondary hosts (mainly Asteraceae, Apiaceae and Apocynaceae) are pale green, yellowish green or deep olive green mottled with yellowish green - with black siphunculi (see first picture below). The abdominal dorsum usually has no dark markings anterior to the siphunculi apart from a few dark intersegmental sclerites (cf. Aphis fabae, which usually has some dark markings anterior to the siphunculi in addition to intersegmental sclerites). The third antennal segment is 1.05-1.95 (usually more than 1.3) times the length of the terminal process. The hind tibiae are pale for more than half their length (cf. Aphis nerii, which has entirely dark or dusky hind tibiae). Tergite VIII usually has 4-6 hairs (it ranges from 2-6) (cf. Aphis gossypii and Aphis spiraecola, which have 2 hairs (rarely 3) on tergite VIII). The siphunculi are 1.5-2.9 times as long as the cauda. The body length of adult apterae is 1.4-2.5 mm. Immature Aphis asclepiadis vary in colour from blue-green to yellow-green to yellow-orange, and fourth instar alatoid nymphs usually have a set of white wax spots.

All images above by permission, copyright Claude Pilon, all rights reserved.

Adult apterae of Aphis (Toxoptera) aurantii are oval, shiny black, brownish-black or reddish brown in colour with rather short black-and-white banded antennae. The antennal terminal process is more than 3.5 times the length of the base of the last antennal segment (cf. Aphis gossypii which has the terminal process less than 3.5 times longer than the base of the last antennal segment). The cauda and siphunculi are black, and the siphunculi are 1.0-1.5 times the length of the cauda. The cauda usually has less than 20 hairs (cf. Aphis (Toxoptera) citricidus which usually has more than 20 hairs on the cauda). A stridulatory apparatus is present below and in front of the siphunculi. The body length of Aphis (Toxoptera) aurantii apterae is about 2 mm long.

Apterae of Aphis ballotae are dark grey-blue to mottled green. Their dorsum is membranous, sometimes with a small postsiphuncular sclerite. The siphunculi are black, and 1.33-1.95 times as long as the dark finger-shaped cauda.. The body length is 1.0-2.0 mm. Aphis ballotae is a member of the Aphis frangulae complex, difficult to distinguish from other members except by biology and host plant.

Adult apterae of Aphis brohmeri (see aphids centre and top left in first picture below) are dark-chocolate to purplish-brown, without any wax powder stripes; antennae and tibiae are pale, with the bases and apices dark, and siphunculi and cauda dark. The antennae are 0.6-0.8 times the body, with the terminal process 2.3-3.2 times the base of antennal segment VI. Secondary rhinaria are usually absent, and the longest hair on segment III is 1.7-2.8 times the base of that segment. The rostrum reaches to the hind coxae, with the apical rostral segment 1.0-1.3 times the second hind tarsal segment. The abdomen has dorsal cross bands on segments VI-VIII, and sometimes partial cross bands on segments I-V, as well as marginal and postsiphuncular sclerites. Abdominal tergites II-VI bear a total of 5-9, often rather large, marginal tubercles (cf. Aphis fabae, which only has 0-3 small marginal tubercles on those tergites). The siphunculi are rather slender and tapering, scaly, 0.10-0.13 times the body, and 1.2-1.6 times the cauda. The cauda is blunt, often slightly constricted in the middle, with the distal part about as thick as the basal part, and with 20-31 hairs (cf. Aphis fabae, which only has 11-24 caudal hairs). Body length of adult Aphis brohmeri apterae is 1.9-2.8 mm. Immatures are paler than the adults, and usually more reddish or yellowish.

Images above by permission, copyright Linda Kjaer-Thomsen, all rights reserved.

Apterae of Aphis brunellae are pale yellow, sometimes with a mid-dorsal suffusion of dark green. They are not wax powdered. In small specimens (body length less than 1.2 mm) the number of antennal segments may be reduced from 6 to 5. The abdominal dorsum is membranous with little or no sclerotic banding. The hairs on the anterior surface of the femora are shorter than the least width of the tibia. The siphunculi are dusky or dark and are 0.92 -1.90 times the length of the pale cauda. The body length of Aphis brunellae apterae is 0.98-1.45 mm.

Immature Aphis brunnea (see pictures below) have a greenish thorax and blue-grey abdomen, with four longitudinal rows of white wax spots (this description may only apply to future alatae). Adult apterae (not pictured) are dull black or blackish brown, with black siphunculi and cauda. The legs are pale apart from the coxae, the distal end of the femora and the apices of the tibiae & tarsi. Antennae are 0.5-0.6 times body length, with the terminal process 2-3 times the base of antennal segment VI. The apical rostral segment (RIV+V) is 1.1-1.4 times the second hind tarsal segment (HTII), and bears 2-6 (usually 4-5) accessory hairs (cf. Aphis fabae, Aphis craccivora and Aphis cytisorum, which have R IV+V 0.9-1.2 × HT II, with only 2 accessory hairs). Dorsal abdominal sclerotization is variable. In the most sclerotized specimens there is a pleural-spinal plate from the metathorax to tergite VI, fused to one of the marginal sclerites. Other specimens have less sclerotization. There are marginal tubercles on tergites I-IV & VII, and sometimes also on V & VI (cf. Aphis fabae, Aphis craccivora and Aphis cytisorum, which have marginal tubercles only sporadically present on tergites II-IV). The siphunculi are subcylindrical, slightly attenuated from base to apex, and with the cuticle distinctly imbricated; they are 1.4-2.2 times the cauda, which has 9-16 hairs. Body length of adult Aphis brunnea apterae is 1.7-2.5 mm.

Images above copyright Faluke, under a Creative Commons License.

Aphis callunae is a small rather stout dark brown aphid which appears pinkish because of the powdering of wax. Blackman describes immature Aphis callunae as 'greenish' in life, but we have found them to be reddish brown (see below). The dorsal cuticle is strongly reticulate. The abdominal tergites are usually only banded on tergites 7-8. The siphunculi are very short, only 0.64-0.79 times the length of the cauda. The body length of Aphis callunae apterae is about 1.7 times the body width (in live specimens), with an absolute body length of 1.0-1.4 mm.

Adult apterae of Aphis ceanothi (see first two pictures below) are dull reddish or amber-brown, with dark siphunculi and cauda. The dorsal abdomen has large black antesiphuncular sclerites, often linked by a transverse sclerite on abdominal tergite VI (cf. Aphis boydstoni in north-west USA & Canada, which has the dorsal abdomen pale, without any antesiphuncular sclerites). The antennal tubercles are weakly developed. The antennal terminal process is 1.5-2.8 times the length of the base of antennal segment VI. The length of the apical rostral segment (IV+V) is about the same as that of second hind tarsal segment. Marginal tubercles are small and only present on abdominal tergites I & VII (cf. Aphis boydstoni, which has the marginal tubercles broad, nearly flat and present on all of abdominal tergites I-VII). The siphunculi are slightly longer than antennal segment III, they are curved outwards, and are more or less cylindrical (cf. Illinoia ceanothi in western USA, which has very long and thin siphunculi, narrow in middle, with distal part dusky and somewhat swollen, narrowing again before the apex). The cauda is about as long as broad at base, and bears 3-4 hairs on each side. The body length of adult Aphis ceanothi apterae is 1.0-2.3 mm.

Images above, copyright Ken Schneider under a creative commons licence.

Adult apterae of Aphis celastrii are described as being yellow or green (but see note below), with black siphunculi and cauda. The legs are greenish yellow, with the apices of the tibiae, femora and tarsi infuscated. The antennae are distinctly shorter than the body, and are without secondary rhinaria. The longest hairs on antennal segment III are about 1.5 times the middle diameter of the segment (cf. Aphis spiraecola, where the longest hair on segment III is usually 0.7-1.0, but up to 0.5-1.7 times the basal diameter of that segment). The abdomen is roundish, with very small marginal tubercles on tergite VII. Siphunculi are very long, often twice as long as the cauda (cf. Aphis spiraecola, which has siphunculi 0.9-1.7 times cauda). The cauda is large, somewhat longer than the tarsi, constricted in the middle with the apex rounded, and bearing 11-19 hairs (cf. Aphis spiraecola, which has 7-15 hairs, but usually less than 12). The body length of adult Aphis celastrii apterae is about 1.5 mm. Immatures are a paler yellow-green. The alate Aphis celastrii (see second picture below) usually has a median sclerite on tergite VII.

Images above copyright Seo, H. et al., NIBR, The Aphids of Korea I,
under a Korea Open Government Licence.

Adult apterae of Aphis cephalanthi are dark purplish brown to almost black with dark siphunculi and cauda. They have wax spots arranged in four spinal and marginal rows along the abdomen. The antennal terminal process is less than the length of antennal segment III, but always much longer than half the length of that segment. The hairs on antennal segment are 0.013-0.018 mm in length (cf. Aphis impatiens which have shorter hairs on that segment). Well-developed marginal tubercles are present on most abdominal segments (cf. Aphis impatiens which usually only has tubercles on segments I & VII). Unusually for an Aphis, the tubercles on abdominal tergite VII are posterior to, and on a level with, the spiracles. The siphunculi are usually shorter than 1.5 times the length of the second hind tarsal segment (HTII). The body length of adult Aphis cephalanthi apterae is 0.9-1.7 mm.

Both images above by permission, copyright Claude Pilon, all rights reserved.

Adult apterae of Aphis cercocarpi (see first picture below) are shining lead-grey to greenish-black. Their antennae and legs are pale with the tips of the joints dusky and the tarsi, siphunculi, cauda, anal plate and genital plate black. The antennal terminal process is 1.3-2.2 times as long as of the base of antennal segment VI. The rostrum almost reaches the 3rd pair of coxae, and the apical rostral segment (RIV+V) is 1.2-1.7 times the length of the second hind tarsal segment (HTII). The abdominal dorsum is reticulated and has dark spots or patches, but no solid dark shield (cf. Aphis craccivora, which has an extensive solid dark shield on the abdominal dorsum). Abdominal tergites II-IV are usually without marginal tubercles, rarely with just 1 or 2 (cf. an undescribed Aphis sp. on Veratrum in western USA, which consistently has marginal tubercles on tergites II-IV). The tibial hairs are rather long, equalling the diameter of the tibia. The siphunculi are cylindrical, broadening at the base, and longer than the cauda (cf. Aphis schuhi, which has siphunculi shorter than the cauda). The short rather wart-like cauda is bluntly tapering to spatulate with a distinct constriction near the base, and bearing 4-12 hairs (cf. Aphis fabae, which has a cauda bearing 11-25 hairs). The body length of adult Aphis cercocarpi apterae is 1.0-2.3 mm.

Images above copyright Andrew Jensen under a cc by-nc-sa licence.

Aphis chloris is rather bright green, pale yellow-green or dark green and is a member of Aphis frangula group. The antennal terminal process is rather short, being 1.6-2.1 times the length of the base of antennal segment VI. The fused terminal rostral segment is also short being only 0.9-1.0 times the length of the second hind tarsal segment. The abdominal dorsum is usually entirely membranous with few if any sclerotized areas. Tibial hairs are short, at most 0.7-1.2 times as long as the least width of the hind tibia, and all femoral hairs are much shorter than the least tibial width. Aphis chloris has dark siphunculi but a slightly paler cauda. The siphunculi are 0.83-1.63 times the length of the cauda. The body length apterae is 1.0-1.8 mm.

Adult apterae of Aphis chrysothamni (see first picture below) have a dark red-brown head and prothorax, a pinkish or greenish mesothorax, metathorax and abdomen. There is a large dark spot on the anterior abdomen, and wax powder on abdominal tergites VII-VIII. Antennal segments II & III are pale, but segments I and IV-VI are dark. The antennae are about half as long as the body and are on very low antennal tubercles (see second picture below). The apical rostral segment (RIV+V) is stiletto-shaped (see third picture below), with RV extended as a needle-like tip (cf. Aphis ornata and Aphis gregalis, which do not have RV extended as a needle-like tip). RIV has a pair of very finely pointed accessory hairs, as long as or longer than the subapical (primary) hairs. RIV+V is 0.11-0.18 mm long, and is 1.1-1.4 times the length of the second hind tarsal segment (HTII) (cf. Aphis chrysothamnicola, which has R IV+V 0.21-0.24 mm long, and is 1.75-2.0 times HTII). The dorsal abdomen usually has a dark central sclerite of irregular shape on tergites I-III or I-IV. The siphunculi are dark, fairly short and tapering. The cauda is dark, very short and broadly pointed. The body length of Aphis chrysothamni apterae is from 1.0 mm (summer dwarfs) to 2.4 mm.

Images above copyright Jesse Rorabaugh under a public domain (CCO) licence.

Adult apterae of Aphis citricidus (previously Toxoptera citricida) are shiny, very dark brown to black, with dark siphunculi and cauda (see first picture below) (cf. Aphis spiraecola, which are yellow or green). The antennae of adult wingless forms and larger nymphs are not striped, but are dark on about the distal half of its length (cf. Aphis aurantii, which has black-and-white banded antennae; and cf. Aphis craccivora, which has the antenna dark on only the distal 0.3 of its length). The terminal process is 4.0-4.5 times as long as the base of antennal segment VI. The longest hairs on antennal segment III are 1.5-2.0 times the basal diameter of that segment (cf. Aphis aurantii, which has the longest hairs on that segment 0.5-1.0 times the basal diameter). The siphunculi are about 1.5 times as long as the cauda. The body length of adult Aphis citricidus apterae is 1.5-2.4 mm.

First image above by permission, copyright Sunil Joshi & Poorani, J. Aphids of Karnataka. (accessed 12/8/20).
Second image above copyright Marco Gaiani under a Creative Commons License.

Adult apterae of Aphis clematidis are dark olive green, with a blackish spinal stripe. On both sides of this stripe, there is a series of transverse oval white wax patches, and also a row of spots along the sides of the abdomen (see first picture below). These spots sometimes merge to give a series of white wax transverse bars (cf. Aphis vitalbae in Europe & Aphis clematiphaga in east Siberia, which are unwaxed). The siphunculi, cauda and legs are mostly pale yellow, apart from dark tips to siphunculi, tarsi and cauda. Pigmentation is variable. Smaller, paler specimens may occur in midsummer. Hairs on antennal segment III are pointed, 0.8-1.5 times the basal diameter of that segment (cf. Aphis clematicola in east Siberia, which has the hairs on antennal segment III short and blunt, 0.5-0.7 that basal diameter). The apical rostral segment (RIV+V) is 0.75-1.0 times the second hind tarsal segment (HTII) (cf. Aphis longituba on clematis in S. & E. Asia & Aphis vitalbae in Europe, both of which have RIV+V 1.1-1.7 times the length of HTII). The siphunculi are longer than the cauda. The body length of adult Aphis clematidis apterae is 1.7-2.3 mm.

First image above copyright Jacobo Krauel, second image copyright Fabriv;
both under a creative common licence.

Aphis clerodendri are monoecious on Clerodendrum where their feeding induces loose leaf pseudogalls (see first picture below). Adult apterae (see second picture below) are straw coloured to bright yellow green or olive green, with black siphunculi and a pale to dusky cauda. Antennae are pale, except for segment I which is dusky, and the apex of segment V and all of segment VI which are dark. Legs are pale, except the apical 0.20-0.25 of the tibiae and all of the tarsi which are dusky to dark. Antennae are 5-6 segmented, 0.52-0.69 times body length, with the terminal process 2.42-2.89 times its base. Hairs on segment III are short and blunt. Hairs on segment V are 2.5-4 times longer than hairs on abdominal tergite VIII (cf. Aphis gossypii, which has hairs on segment V 4-9 times longer than hairs on tergite VIII). The apical rostral segment is 1.2-1.36 times the second hind tarsal segment, and bears 2-3 secondary hairs. Aphis clerodendri apterae have well developed marginal tubercles on the prothorax and segments II and VII, with small marginal tubercles occasionally present singly on segments IV and VI. Siphunculi are 0.10-0.20 times body, and 1.32-1.86 times cauda. The cauda bears 4-9 hairs, which become stouter and more curved towards the apex. Body length of adult Aphis clerodendri apterae is 1.1-1.9 mm.

Images above copyright Seo, H. et al., NIBR, The Aphids of Korea I,
under a Korea Open Government Licence.

Adult apterae of Aphis commensalis are darkish grey-green with a heavy greyish wax coating (see first picture below). The abdominal dorsum has no pigmented sclerites except for faint narrow bands across tergites 7-8. Small marginal tubercles are present on the first and seventh abdominal tergites. Hairs on the tibiae are long and fine, the longest on the hind tibia being 1.7-2.4 times the least width of the tibia. The dusky siphunculi are rather short being only 0.9-1.2 times as long as the cauda. The cauda is short and blunt. Body length of the adult Aphis commensalis aptera is 0.9-1.7 mm.

Adult apterae of Aphis confusa (see large pale green apterae in first picture below) are pale green, mottled to a greater or lesser degree with darker green. Some small midsummer apterae living low down on the plant are wholly pale yellow, and many are alatiform with secondary rhinaria and wing rudiments. The antennae are 6- or 5-segmented (the latter mainly in small midsummer specimens), with the terminal process 1.5-3.3 times as long as the base of antennal segment VI. The apical rostral segment is 1.1-1.4 times the length of the second hind tarsal segment. The abdominal dorsum is membranous, sometimes with a small siphuncular sclerite. The abdomen has rather small marginal tubercles on tergites I & VII, with occasional ones on other tergites. The posterior hair on the hind trochanter is quite long at 0.6-1.1 times the diameter of the trochanto-femoral suture (cf. Aphis thomasi on Scabiosa, which has the hairs on the hind trochanter shorter, at 0.2-0.5 times the diameter of the trochanto-femoral suture). The siphunculi and cauda are similarly pigmented - dark in green specimens, pale or dusky in yellow ones (cf. Aphis gossypii, where the siphunculi are usually much darker than the cauda). The siphunculi are 0.82-2.21 times the caudal length. The body length of adult Aphis confusa apterae is 1.0-2.3 mm.

Images above by permission, copyright El Gritche, all rights reserved.

Adult apterae of Aphis coreopsidis (see first two pictures below) are yellow with a variable degree of dark green mottling especially along the spinal area. There is sometimes an orange suffusion around and between their siphunculi. The head and antennal segments I, II, and the basal part of III, are very pale, contrasting with the rest of the antenna which is dark. The antennal terminal process is 4 or more times as long as the base of antennal segment VI. Their legs are mostly pale-dusky, but the apical parts of the tibiae are somewhat darker. The siphunculi are dark, about twice as long as the cauda, and 0.24-0.40 times the body length. The cauda is longer than broad and much paler than the siphunculi. The body length of adult Aphis coreopsidis apterae is 1.5-1.8 mm.

First image above by permission, copyright Claude Pilon, all rights reserved.
Second images above, copyright glmory under a public domain (CCO) licence.

The (newly described) horned oxtongue aphid - Aphis cornuta - lives in ant-tented colonies at the stem base of prickly oxtongue (Picris echioides, see first picture below). Adult Aphis cornuta apterae are bright yellow to yellow-green with dark siphunculi and dusky cauda (see second picture below). There are sometimes pale brownish-green sclerotic areas laterally on the thoracic and first abdominal tergites, brownish-green cross-bands on abdominal tergites 7 and 8, and small brownish-green triangular patches posterior to the bases of the siphunculi. The antennal terminal process is 3.13-4.13 times the length of the base of segment 6 (cf. Aphis picridis where the antennal terminal process is 2.0-2.8 times longer than the base). The rostrum is long - extending back well beyond the bases of the hind coxae, 0.38-0.57 times the body length (cf. Aphis picridis in which the rostrum is also quite long at 0.35-0.46 times the body length). The apical rostral segment (R IV+V) is 1.40-1.78 times longer than second segment of hind tarsus (HTII). Aphis cornuta aptereae have exceptionally large marginal tubercles on the prothorax with a basal diameter usually > 50 μm (cf. Aphis ochropus which has the basal diameter of its prothoracic tubercles < 50 μm. Blackman, pers. comm.) - hence the English name of horned oxtongue aphid. There are also quite large marginal tubercles on abdominal tergites 1 and 7, and also often smaller ones on abdominal tergite 6 (cf. Aphis picridis which only has small marginal tubercles on tergites 1 and 7). The siphunculi are 1.91-2.82 times longer than the cauda (cf. Aphis picridis which has the siphunculi 1.6-1.9 times longer than the cauda). The cauda is tongue-shaped with a slight midway constriction and bears 6-8 hairs.

Aphis coronillae lives in ant-tented colonies on the basal parts of clovers and medicks (see first picture below). The adult aptera of Aphis coronillae (see second picture below) is pinkish brown to brownish green with a more or less shiny black dorsal shield and no wax powdering. The shield extends over segments 1-6 inclusive, but is weakened by membranous lines between some of the anterior segments. The shield is reticulated, a feature formerly only thought to be visible in slide mounted specimens, but also apparent in photos of the live insect. Abdominal tergites 1-4 and 7 regularly bear very protuberant, dome-shaped marginal tubercles, clearly visible in the pictures below (cf. Aphis craccivora where tergites 2-6 are usually without marginal tubercles, or rarely with 1-3 small ones). Nearly all the hairs on the legs are very short. The body length of adult Aphis coronillae apterae is 1.3-2.2 mm.

Aphis coronillae alatae (see third picture above) are reddish brown with bands on most or all abdominal tergites, that on tergite VI being broader and amalgamated with the postsiphuncular sclerites. They have 3-9 secondary rhinaria on antennal segment III, and 0-2 on segment IV. Immatures range from greenish-yellow (the youngest) to reddish brown (fourth instars).

There are two subspecies with specific host-plant associations, but the morphological discriminants for the two subspecies are slight:

1. Aphis coronillae coronillae (clover aphid) lives on Trifolium species.
2. Aphis coronillae arenaria (medick aphid) lives on Medicago lupulina.

Adult apterae of Aphis craccae (see first picture below) are covered in a dense layer of grey wax powder (cf. Aphis craccivora, where the adult apterae have little or no wax on the dorsal surface, although immatures are waxed). Under the wax they have an extensive solid black shield on the dorsal abdomen which covers the whole width of tergites V and VI, and normally extends forward over the central areas of tergites I-IV, often with lateral extensions towards the intersegmental muscle sclerites. Their antennae are about the same length as the body, and the terminal process is 1.70-2.4 times the length of the base of antennal segment VI (cf. Aphis adesmiae, in South America, whose terminal process is 1.40-1.69 times the length of that segment). The dark siphunculi are 0.7-1.0 times as long as the dark, elongate, cauda (cf. Aphis craccivora, which has the siphunculi 1.1- 2.2 times the length of the cauda, and Aphis pseudocomosa, whose siphunculi are 1.1-1.6 times the caudal length). Abdominal tergite VIII usually has more than 2 hairs. The body length of adult Aphis craccae apterae is 1.9-2.8 mm.

All images above by permission, copyright Claude Pilon, all rights reserved.

The aptera of Aphis craccivora (see first picture below) is dark brown with (usually) a very solid black shiny carapace from the metanotum to abdominal tergite 6. Many North American and a few Southern European Aphis craccivora populations have a reduced sclerotic shield. The longest hair on the third antennal segment is usually 0.5-0.6 times the basal diameter of that segment (cf. Aphis pseudocomosa which has the longest hair on the third antennal segment 0.67-1.38 times the basal diameter of that segment). Their siphunculi very rarely have any trace of constriction before the flange, and are 1.2-2.2 times the length of the cauda (cf. Aphis loti which has the siphunculi 0.8-1.5 times the length of the cauda). The cauda has the distal part tapering and is 0.09-0.13 times body length (cf. Aphis loti which has the cauda finger-like, almost parallel sided on the distal part). The body length is 1.16-2.3 mm.

Aphis crepidis apterae are dark bluish-green to yellow-green, and are not wax powdered (see first picture below). The dorsum of Aphis crepidis is membranous apart from a rather faint short dusky spinal bar on tergite 8, and marginal tubercles are prominent. The femora and proximal tibial hairs are shorter than the least width of the tibia. The siphunculi are dark. The cauda is dusky and bears 6-11 hairs (cf. Aphis hypochoeridis which has 4-8 caudal hairs). The body length of Aphis crepidis is 1.2-2.0 mm.

Adult apterae of Aphis crinosa are yellowish brown, with dark siphunculi and a dusky yellow cauda. The aphids are usually covered with white wax secretion which obscures the body colour, but just after moulting the yellowish brown body colour is visible (see first image below). The antennae are shorter than the body, with segment III equal to the sum of segments IV & V; the terminal process is more than 3 times the base of segment VI. The longest hairs on antennal segment III are more than 3 times the basal diameter of that segment. Siphunculi are short, cylindrical or slightly swollen, and have no flange; they are similar in length to the short cauda, which bears more than 14 hairs (cf. Myzus ligustri, which has siphunculi 2.6-3.2 times longer than longer than the cauda, which bears 5-6 hairs). The body length of adult Aphis crinosa apterae is 2.3-2.7 mm.

Images above copyright Seo, H. et al., NIBR, The Aphids of Korea I,
under a Korea Open Government Licence.

Adult apterae of Aphis cuscutae are pale green (see bottom-left, first picture below), with the entire body covered with a very thin pulverulence. There is a small postsiphuncular sclerite (cf. Aphis gossypii, which has no postsiphuncular sclerite). The siphunculi are black, and the cauda pale greenish to dusky (cf. Aphis hederae and Aphis fabae, which both have the cauda as dark as the siphunculi). The antennae are black, excepting the basal two-thirds of segment III, which is pale. The longest hair on antennal segment III is 0.8-1.0 times the basal diameter of that segment (cf. Aphis gossypii, which has longest hair on segment III 0.4-0.8 times the diameter). The rostrum reaches a little beyond the second pair of coxae. The prothorax bears a pair of marginal tubercles. The siphunculi are moderately long, 2.5-2.9 times the cauda and curved outwards (cf. Aphis gossypii, which has straight siphunculi, 0.9-2.5 times the cauda). The cauda is conical and bears 6-9 hairs (usually 7-8). The body length of adult apterae is 1.5-2.1 mm. Fourth instar immatures (see first picture below) bear a row of often very conspicuous wax spots on each side of the median dorsal line, and the entire body is covered with a fine inconspicuous wax powder.

Images above copyright James Bailey under a Creative Commons License.

Aphis cytisorum is a very dark green aphid which may appear greyish because of the strong wax secretion (see pictures below). The adult aptera has a dark sclerotized dorsal abdominal shield, which is often rather fragmented and variable in size, and is especially reduced in small specimens. The dark sclerotic areas are strongly reticulate. There are areas of membranous cuticle along the side bounded by the mid-dorsal shield and the intersegmental muscle sclerites. The apical rostral segment (RIV+V) is 0.97 to 1.3 times the length of the second hind tarsal segment (HT II). Marginal tubercles may be present. The longest tibial hairs are a little longer than the least width of the hind tibiae. The siphunculi and cauda are dark, but the antennae and tibiae are mostly pale. The siphunculi are 1.2 to 2.2 times as long as the cauda. The body length of apterae is 1.4-2.5 mm.

Alatae (see third picture above) have the dorsal shield broken up into segmental bands, marginal sclerites and postsiphuncular sclerites, with areas of membranous cuticle along side the segmented bands on the abdominal tergites.

Adult apterae of Aphis decepta have a yellow body, with the lateral portions of the thorax and small patches on the abdomen immediately posterior to the siphunculi dark brown (note the Aphis decepta pictured below are yellow-green immatures and lack the darker markings - also note they are mixed with grey Aphis fabae immatures). Their antennal tubercles are weakly developed. The antennae are pale basally, shading to brownish by the middle of antennal segment V. The apical rostral segment (RIV+V) is 1.1-1.4 times as long as the second hind tarsal segment (HTII). There are marginal tubercles on abdominal tergites I & VII. The siphunculi are dark brown, darker and a little longer than the cauda. The cauda has about 12-14 hairs (cf. Aphis gossypii, which also has siphunculi darker than the cauda, but has only 4-7 hairs on the cauda). The anterior half of the subgenital plate has only 2(-3) hairs (cf. Aphis asclepiadis, which usually has more than 2 hairs on the anterior half of the subgenital plate). Immature Aphis decepta are greenish-yellow.

Images above by permission, copyright Claude Pilon, all rights reserved.

Feeding by Aphis egomae crinkles the leaves of its host (Perrilla), producing a crumpled leaf pseudogall (see first picture below) which houses the aphid colony. Adult apterae of Aphis egomae (see second picture below) are pale yellow to yellow-green or orange, with black siphunculi and a pale yellow cauda; the antennae are pale with a dark tip. Antennal tubercles are weakly developed. Antennae are (usually) 5-segmented (cf. Aphis gossypii, which usually has 6-segmented antennae), and are about 0.70 times body length. The apical rostral segment (RIV+V) is less than 1.5 times the second hind tarsal segment (HTII) (cf. Aphis passeriniana, which has RIV+V 1.54-2.02 times HTII). There are marginal marginal tubercles on abdominal tergites I and VII. Siphunculi taper from a broad base (cf. Cryptomyzus taoi on Physostegia, which has siphunculi distinctly swollen on the distal half ); the sipunculi are about 0.2 times body length and 1.6 times the cauda. Body length of Aphis egomae apterae is unrecorded (described as 'small').

Images above copyright Seo, H. et al., NIBR, The Aphids of Korea I,
under a Korea Open Government Licence.

The adult aptera of Aphis epilobiaria is a reddish-brown to blackish-brown or blackish green, but the colour is mostly masked by a striking pattern of dense pleural wax bands (see first picture below). These converge on the thorax and posterior tergites to occupy most of the width of the dorsum, leaving a spindle-shaped area of the mid-dorsum without wax. The abdominal dorsum of the apterous Aphis epilobiaria is membranous with only a dusky narrow band across tergite 8 and sometimes 7. There are small marginal tubercles on tergites 1 and 7. The apical rostral segment (RIV+V) is 1.3-1.6 times the length of segment II of the hind tarsus and has 6 or more subsidiary hairs. The second tarsal joint is almost entirely smooth (cf. Aphis epilobii where it is ridged). The siphunculi are 1.0-1.6 times the length of the cauda and often bear a few fine hairs. The siphunculi are usually quite pale, sometimes a little dusky. The cauda is quite dark. The body length of apterae is 2.2-2.7 mm.

Adult apterae of Aphis epilobii are dark blackish-green to reddish-brown (see first picture below) which often appears dark-grey to pinkish-brown (see second picture below) because of a rather uniform powdering of wax (cf. Aphis grossulariae which is dull green to light green with only a light wax bloom). The apical rostral segment (R IV+V) is 1.28-1.55 times the length of segment II of the hind tarsus (HT II) (cf. Aphis grossulariae which has R IV+V 1.42-1.68 times the length of HT II). The abdominal dorsum of Aphis epilobii is membranous with only a dusky narrow band across tergite VIII and sometimes VII. There are small conical marginal tubercles on tergites I and VII (visible if you can expand the first micrograph image below), but not on tergites II-VI (cf. Aphis grossulariae which has marginal tubercles on most tergites). The siphunculi and basal parts of the antennae are pale, but the cauda is dusky. The siphunculi are 1-1.6 times the length of the cauda. The body length of Aphis epilobii apterae is 1.3-2.1 mm. Immatures (see second picture below) resemble the adults with blackish-green and reddish-brown forms.

Adult apterae of Aphis epipactis are very dark green, almost sooty black, as in the first picture below. The terminal process of antennal segment VI is 2.7-2.9 times the length of its base. The femora and tibial hairs are much longer than the least width of the tibiae, making Aphis epipactis a member of the "long-haired black-aphis group", which includes Aphis ilicis and Aphis viburni. The siphunculi are 1.0-1.1 times the length of the cauda. The body length is 1.43-1.69 mm (estimated allowing for effects of dehydration on the type specimens).

Note: There are no satisfactory distinguishing characters from other members of the "long-haired black aphis group". Aphis epipactis may well be synonymous with Aphis viburni, or possibly Aphis ilicis.

Aphis euphorbiae apterae are dark blackish brown and are rather strongly wax powdered. They have a dark dorsal shield (clearly visible in the first picture below) which is confined to a rather rectangular mid-dorsal area. The cauda is rather slender and tapering. Marginal tubercles are protuberant and often present on abdominal tergite 6. Aphis euphorbiae body length is 1.7-2.1 mm.

Guest images copyright Jivko Nakev, all rights reserved.

The adult aptera of Aphis evonymi (see first picture below) is a reddish- to chocolate-brown with broad dark sclerotic bands across the pronotum and mesonotum, and narrower ones across abdominal tergites 7-8. It consistently lacks marginal tubercles on abdominal tergites 2-4 (cf. the similarly coloured Aphis ilicis and Aphis viburni which tend to have marginal tubercles on abdominal tergites 2-4). The longest hairs on the third antennal segment is 2-3 times as long as the basal diameter of that segment (cf. Aphis fabae which has longest hairs on the third antennal segment 0.6-2.4 times as long as the basal diameter of that segment). The middle and hind femora are mostly dark and tibiae are darkened on the apical quarter. The body length of Aphis evonymi adult aptera is 1.7-2.9 mm.

The Aphis fabae adult aptera is matt black or very dark brown, sometimes with a distinct greenish hue. It has a variable abdominal sclerotic pattern - confined to abdominal tergites 6-8 in smaller apterae, but broken bands are present in larger ones. Marginal tubercles are protuberant but small. The antennae usually have segments III-IV and the base of V quite pale. The longest femoral and tibial hairs are longer than the least width of the tibia. Their siphunculi and cauda are dark. The black bean aphid immatures (see second picture below) often have discrete white wax spots, as do sometimes the adults. The body length of Aphis fabae adult apterae is 1.2-2.9 mm.

Aphis farinosa apterae are quite small, and are green mottled with yellow-orange. The antennal terminal process is 1.6-2.3 times as long as the base of antennal segment VI. The abdominal dorsum in apterae is usually entirely pale and membranous with fairly numerous protuberant, hemispherical or teat-shape marginal tubercles on the tergites. The siphunculi are long and pale with a slightly dusky tip and the cauda is distinctly darker. The siphunculi of the aptera are 1.74-2.95 times as long as the cauda. The body length of Aphis farinosa apterae is 1.6-2.5 mm.

Adult apterae of Aphis folsomii are dark reddish brown, with dark or dusky siphunculi (see first picture below). Their antennal tubercles are weakly developed. The antennae of apterae are pale, apart from segment VI which is dark. The longest hairs on the third antennal segment are less than 3.5 times the basal diameter of the base of antennal segment III. The apical rostral segment (RIV+V) has 8-10 accessory hairs (cf. Aphis illinoisensis and Aphis fabae, which each have only 2 accessory hairs on RIV+V). Abdominal tergites 1 and 7 always have marginal tubercles. Their legs are dark apart from the apical parts of the tibiae. The cauda is short and broad, about as long as its basal width, with more than 20 hairs (cf. Aphis illinoisensis and Aphis fabae, which each have the cauda much longer than its basal width, with 7-19 hairs). The body length of adult apterae is 1.6-1.8 mm. Immature Aphis folsomii are light reddish brown with pale siphunculi.

Images above by permission, copyright Claude Pilon, all rights reserved.

Adult apterae of Aphis forbesi (see first picture below) are dark bluish green, sometimes with bluish-yellow mottling. The antennal tubercles are weakly developed. The apical rostral segment (RIV+V) is 1.6-1.9 times the length of the second hind tarsal segment (HTII) (cf. Aphis fabae & Aphis gossypii which both have a shorter RIV+V at 0.9-1.5 times the length of HTII). The cauda is tongue-shaped and longer than its basal width. The body length of adult apterae is 1.0-1.9 mm. Immature Aphis forbesi (see second picture below) are yellowish green.

Aphis frangulae apterae are generally dark green or blue-green, sometimes mottled (see pictures of apterae on the primary and secondary hosts below). Their abdominal sclerotic pattern is variable - it is usually confined to abdominal tergites 6-8 in smaller apterae, but broken bands are present in larger adults. The siphunculi are dusky or dark and are 0.85-2.16 times the length of the pale or dusky cauda. The body length of Aphis frangulae apterae is 0.9-2.4 mm.

Adult Aphis fukii apterae (see first picture below) are yellowish-brown to grey-brown, with black siphunculi and cauda (cf. Aphis gossypii, which has the cauda pale or dusky). Antennae are about 0.8 times body length, with a terminal process a little over twice as long as the base of antennal segment VI. The rostrum reaches the hind coxae, with the apical rostral segment about 1.5-1.7 times the second hind tarsal segment. Marginal tubercles are only consistently present on abdominal tergites I & VII (cf. Aphis torquens in Europe, which has well-developed conical or hemispherical marginal tubercles present on tergites II-IV(-V) as well as I and VII). Siphunculi are 1.7-2.1 times cauda (cf. Aphis torquens, which has siphunculi 0.8-1.4 times cauda). The cauda bears 10-16 hairs (cf. Aphis gossypii, which has 4-8 hairs on the cauda; and cf. Aphis torquens, which has 16-21 hairs on the cauda). Body length of adult Aphis fukii apterae is 2.1-2.5 mm.

Images above copyright Seo, H. et al., NIBR, The Aphids of Korea I,
under a Korea Open Government Licence.

Adult apterae of Aphis 4genistae are black, and have a black cauda and siphunculi, but are quite thickly coated with wax meal. The hairs on antennal segment III are 0.8-1.3 times the basal diameter of that segment (cf. Aphis ononidis, which has shorter hairs on that segment - only 0.3-0.4 times the basal diameter of that segment). The dorsal abdomen has extensive dark sclerotisation (cf. Aphis fabae, which only has a few small dark spots anterior to the siphunculi). Their siphunculi are quite short, only 0.5-0.8 times as long as the cauda (cf. Aphis craccivora and Aphis cytisorum, which both have siphunculi 1.1-2.2 times the length of their cauda). The body length of adult Aphis genistae apterae is 1.4-2.6 mm.

Both images above by permission, copyright Claude Pilon, all rights reserved.

Adult apterae of Aphis gerardiae (see first picture below) are blackish-brown with black siphunculi and cauda. Their antennae are mostly pale, other than antennal segments I & II and the bases and apices of other segments which are dark. The hind tibiae are uniformly dark, or only a little paler in middle (cf. Aphis fabae, which has mostly pale hind tibiae, dark only at the ends). Their siphunculi are about 1.5 times as long as the cauda and equal to, or longer than, twice the length of the hind tarsi (exclusive of claws). The cauda has 7-11 hairs (cf. Aphis fabae, whose cauda has 11-24 hairs). The body length of adult apterae is 1.9-2.9 mm. Immature Aphis gerardiae (see second picture below) are reddish brown.

Both images above by permission, copyright Claude Pilon, all rights reserved.

Adult apterae of Aphis glycines (see first picture below) range from pale yellow to lime green in colour, commonly green mottled with pale yellow. On late season soybeans, some aphids may be much smaller and paler than usual. The insect's head is pale, as are the basal antennal segments, and the antennal tubercles are weakly developed. The siphunculi are dark except at their bases (cf. Aphis nasturtii which has the siphunculi usually rather pale, only darker at the apices). The cauda is very pale, usually with a slight midway constriction, more than 3 times longer than its narrowest width at midlength, and usually bearing 7-9 hairs (cf. Aphis gossypii for which the cauda is pale to dusky, without a constriction, less than 3 times longer than its width at midlength, and usually bearing 5-6 hairs). The body length of adult Aphis glycines apterae is 1.2-1.7 mm.

Wingless females of Aphis gossypii are usually medium-sized and blackish green or green mottled with dark green (see first picture below). In hot conditions or when crowded they are smaller and are a very pale whitish yellow. The dorsum has no dark sclerotized markings. The longest hairs on the third antennal segment are 0.3-0.5 times the basal diameter of that segment. The terminal process of the last antennal segment is 1.7-3.2 times the length of the base of that segment. The apical segment of the rostrum is 1.1 to 1.5 times the length of segment 2 of the hind tarsus. Marginal tubercles are only consistently present on abdominal tergites 1 and 7. The siphunculi are dark. The cauda is usually paler than the siphunculi and bears 4-8 hairs. The body length of adult Aphis gossypii apterae ranges from 0.9-1.8 mm.

Adult apterae of Aphis gregalis (see two pictures below) are bluish-green to yellowish-green, with darker head and pronotum, and variably-developed dorsal abdominal dark markings. The body is covered with a thin dusting of grey wax. The head is rounded in front, with only slight antennal tubercles. The antennae are black, apart from the base of antennal segment III. They are about 0.4 times body length, with circular secondary rhinaria distributed 0-3 toward the distal end of the segment III, and 0-1 on IV. The terminal process is 1.1-1.5 times the base of antennal segment VI (cf. Aphis ornata, which has the terminal process 1.3-2.0 times the base of antennal segment VI - note the overlap of ranges and see note below). The rostrum reaches the third coxae, and the apical rostral segment is not extended as a needle-like tip (cf. Aphis chrysothamni, which has the apical rostral segment extended as a needle-like tip). Marginal tubercles are well developed on most abdominal segments, as well as on the first two thoracic segments. Siphunculi are black, and slightly bent downward. The cauda is black, almost conical, with a very slight constriction near the base. The anal plate is black and rounded. Body length of adult Aphis gregalis apterae is 1.2 to 1.85 mm.

First image above copyright Jared Shorma, second copyright Andrew Jensen
both under a creative common licence.

The adult aptera of Aphis grossulariae (see first picture below) is dull green to dark green and is slightly to moderately wax powdered. The antennae are shorter than the body, and the hairs on the third antennal segment are straight or curved and at most 1-2 times the least width of that segment (cf. the very similar Aphis schneideri which has the hairs on the third antennal segment fine and wavy and conspicuously erect, 1.8-4.0 times the basal diameter of that segment). The abdominal dorsum is entirely membranous or at most has narrow dusky bands across tergites 7 & 8. Aphis grossulariae has marginal tubercles present on at least some of abdominal tergites 2-6 (cf. Aphis epilobii and Aphis epilobiaria which have no marginal tubercles on abdominal tergites 2-6.) The siphunculi and legs are pale except for the tibial apices and tarsi which are dusky. The longest tibial hairs are greater than the least width of the hind tibia. The cauda is pale or slightly dusky. The body length of adult apterae is 1.2-2.1 mm.

The apterae of Aphis hederae (see first picture below) are dark greenish or reddish brown although immatures are paler. They are supposedly not waxy, although the immatures here appear to have a wax 'bloom'. The abdominal sclerotic pattern is mostly confined to a band on abdominal tergites 6-8. The body length of Aphis hederae apterae is 1.4-2.5 mm.

Adult apterae of Aphis hieracii (see pictures below) are bluish to dark green, with a dark head, cauda and siphunculi (cf. Aphis fabae, which is black, or very dark brown). The antennal flagellum (=segments III-VI) is pale on the basal half, and apically darker, the tarsi are dark, and the tibiae are pale-dusky with dark apices. The antennae are (5)6-segmented, 0.5-0.7 times the body, and with the terminal process 1.8-2.5 times the base of antennal segment VI. There are usually no secondary rhinaria in apterae. The longest hair on antennal segment III is 0.8-1.6 times the basal diameter of that segment. The rostrum reaches to or behind the hind coxae, with the apical segment slender, and 1.1-1.4 times the second hind tarsal segment. The dorsum is without sclerotized areas in front of the siphunculi (cf. Aphis fabae, which usually has scattered dark sclerotic markings anterior to the siphunculi). Larger specimens sometimes have a diffuse spinal sclerite on tergite VII, and a transverse bar on tergite VIII. The longest hairs on abdominal tergite III are 25 μm long, about 1.3 times the basal diameter of antennal segment III (cf. Aphis heie, which has the longest hairs on tergite III 50-70 μm long, 2.5-3.5 times the basal diameter of antennal segment III). The siphunculi are 1.3-1.8 times the caudal length with a rather small, but distinct flange. The cauda is tongue-shaped, with 6-8 hairs. Body length of normal adult Aphis hieracii apterae is 1.2-1.8 mm, but in mid-summer there are dwarf apterae which are yellow or yellow-green, with body length only 0.8-1.1 mm.

Both images above by permission, copyright Marko Šćiban, all rights reserved.

Adult apterae of Aphis horii (see largest individuals in first picture below) are dark green, with the head, antennae, siphunculi, cauda, anal plate and legs almost black. The abdomen has dark sclerotic cross bands on tergites VII and VIII. The antennae are rather short, and bear long and very fine hairs, the longest on segment III being 1.7-2.1 times the basal diameter of that segment (cf. the closely related Aphis sambuci, which has shorter hairs on segment III, the longest only 0.5-1.7 times the basal diameter). There are no secondary rhinaria on antennal segment III. The rostrum reaches beyond the middle coxae. The prothorax has a large marginal tubercle, and the abdomen has quite large domed marginal tubercles on tergites I-V & VII. The siphunculi are very long and slender, distinctly curved, moderately dilated towards the base, much longer than the 3rd antennal joint, and 2.2-4.0 times longer than the cauda. The cauda is short, dark and blunt, and is provided with many long fine hairs. The body length of adult Aphis horii apterae is 2.1-2.7 mm.

First image above Nan Yang, second image copyright zdk0812,
both under a creative common licence.

Apterae of Aphis hypochoeridis are bright yellow to pale greenish yellow, often with orange hues (see first picture below). The antennal terminal process is 1.5-2.7 times the length of the base of antennal segment VI. The abdominal dorsum is entirely pale or with dusky bands across tergites 7-8 only. The siphunculi are dark. They are 3.5-7.1 times their midlength diameters, and 0.9 to 1.6 times the length of the elongated pale or dusky finger-shaped cauda. The body length of adult apterae of Aphis hypochoeridis is 0.7-1.6 mm.

Adult apterae of Aphis ichigocola (see first two pictures below) are yellow to greenish yellow to brownish yellow, with a dark brown head, a dark green pronotum, dark green patches on abdomen around and between siphunculi, black siphunculi and a pale cauda. Antennae have segment I dark, II-III pale, and remainder dusky to dark; femora and tibiae are dark apically, and tarsi dark. Dorsal hairs on head are conspicuous, long and blunt. Antennae are 5-segmented, about 0.57 times body length, with the longest hairs on segment III about equal to, or more than, the mid-segment diameter; the terminal process is long, 4.3-5.2 times the base of segment V (cf. Aphis ichigo, which has the terminal process between 1.3-3.6 times the base of the segment). The rostrum reaches the middle coxae, with the apical rostral segment about 1.3 times the second hind tarsal segment. The abdomen is not reticulated, but has distinct brown scleroites at the bases of spinal hairs on tergites I-V (VI) plus larger marginal sclerites (cf. Aphis ichigo, which lacks spinal scleroites). Siphunculi are about two times cauda, with a distinct flange. The cauda is well constricted and rounded on the distal part, with 11-12 hairs. Body length of adult Aphis ichigocola apterae is 1.5-2.0 mm.

Images above copyright Seo, H. et al., NIBR, The Aphids of Korea I,
under a Korea Open Government Licence.

Viviparous apterae of Aphis idaei are small mottled green and yellow aphids with a rather even wax pulverulence giving an overall pale green colour. The abdominal dorsum in apterae is quite pale. Aphis idaei is characterized by the combination of long very slender dusky siphunculi and a short thick blunt cauda. The siphunculi of Aphis idaei apterae are 2.4-3.3 times as long as the cauda. In midsummer their progeny develop into dwarf apterae which are pale cream and live dispersed between the veins of the underside of the leaves. The body length of apterae is only 1.3-2.2 mm (dwarfs 0.8-0.9 mm).

Aphis ilicis apterae are dark olive-brown, reddish-brown or greyish-brown. The sclerotic dark banding of the dorsum is variable - it is confined to the latter abdominal tergites in small apterae, but there are broken bands on some anterior tergites in larger apterae. Aphis ilicis siphunculi are black, rather short and slightly tapered distally. The siphunculi are 1.15-1.67 times longer than the dark, blunt, finger-shaped cauda. Aphis ilicis is a member of the Aphis fabae group, so immatures may have white pulverulence. Adult apterae have a body length of 1.7-2.9 mm.

Adult apterae of Aphis illinoisensis are quite shiny, varying in colour from reddish brown to almost black (see first two pictures below). The antennal tubercles are weakly developed. Antennal segments III, IV and V are dark at their apices. The antennae are 0.7-0.9 times as long as the body, with the terminal process 1.1-4.0 times the length of the base of antennal segment VI. The apical rostral segment (RIV+V) has 2 accessory hairs. The fore-legs have the femora and mid-tibiae pale, but the mid-legs are mainly dark, and the hind tibiae are wholly black (cf. Aphis fabae, Aphis gossypii & Aphis craccivora, which all have the hind tibiae mainly pale with black apices). Their siphunculi are black, curved outwards and quite long, approximately equal in length to the terminal process of antennal segment VI. The cauda is deep brown, distinctly constricted in the middle and is much longer than its basal width (cf. Aphis folsomii, which has a short and broad cauda, about as long as its basal width). The body length of adult apterae is 1.6-2.1 mm. Immature Aphis illinoisensis (see second picture below) are reddish brown with dark siphunculi.

First and third image above by permission, copyright Claude Pilon, all rights reserved.
Second image above copyright Stan Gilliam under a Creative Commons Attribution License.

Adult apterae of Aphis impatientis (see first picture below) have a black head, siphunculi and cauda, and a purplish brown or brownish abdomen dusted with white wax. Antennal segments I & VI are dusky, and the others pale. The antennae are six-segmented, and shorter than the body (cf. Uroleucon impatiensicolens, Macrosiphum impatientis and other Macrosiphum species on Impatiens, which all have antennae longer than the body). The antennae are without secondary rhinaria. The hairs on antennal segment III are short, usually less than middle diameter of that segment (cf. Aphis maculatae, Aphis fabae, Aphis neogillettei & Aphis salicariae, which all have those hairs longer than the middle diameter of the segment). The rostrum reaches to the mesocoxae. The apical rostral segment (RIV+V) is 0.7-1.0 times the second hind tarsal segment (HTII) (cf. Aphis nasturtii, which has RIV+V 0.9-1.2 times HTII). Marginal sclerites are pale, but pre-siphuncular and post-siphuncular sclerites are absent. Marginal tubercles are present on abdominal segments I and VII, but absent from II, III, and IV. The siphunculi are dark, curved outwards with flange, much broader at the base than at the apex, and 0.9-1.6 times the caudal length (cf. Aphis cornifoliae on dogwood, which has siphunculi hardly broader at base than apex, and 1.2-2.0 times longer than the cauda). The cauda is dark, thumb-shaped and blunt. The body length of adult Aphis impatientis apterae is 1.0-1.8 mm.

First image above copyright James Bailey, second image copyright Ryan Sorrelis;
both under a Creative Commons License.

Adult apterae of Aphis intybi are black and wax-powdered to a greater or lesser extent, giving them a matt grey-black appearance (see first two pictures below) (cf. adult Aphis craccivora, which have a shiny black carapace). The dorsal abdomen has dark markings which are usually fused between segments to form a central patch or shield (cf. Aphis fabae, which has some dark markings on the dorsal abdomen, but they are not fused between segments). The hairs on antennal segment III are 0.25-0.75 times the basal diameter of that segment (cf. Aphis fabae, which has hairs on antennal segment III 0.8-3.4 times the basal diameter of that segment). The apical rostral segment (RIV+V) is 1.1-1.5 times the length of the second hind tarsal segment (HTII) and usually 1.25-1.75 times the base of antennal segment VI (cf. Aphis craccivora, which has RIV+V 0.7-1.3 times HT II, and usually 0.8-1.2 times the base of antennal segment VI). The siphunculi and cauda are both black. The cauda bears 4-9 hairs (cf. Aphis fabae, which has 11-27 hairs on the cauda). The body length of adult Aphis intybi apterae is 1.2-2.3 mm.

Both images above by permission, copyright Claude Pilon, all rights reserved.

Aphis jacobaeae are usually found under ant tenting on ragwort (see first picture below). The apterae are dark green and are not wax powdered (cf. Brachycaudus lateralis which is also found on ragwort under ant tenting, but has a shiny black dorsum). The thorax has rather extensive dark lateral sclerites, whilst the abdomen has small marginal sclerites on tergites 2-4, small sclerites just behind the siphunculi, dark bands across tergites 7-8, sometimes a small median sclerite on 6, and dark intersegmental muscle sclerites. The marginal tubercles are prominent. The siphunculi have a conspicuous apical flange. The legs are dark except for the extreme bases of their femora. This feature will usually distinguish Aphis jacobaeae from Aphis fabae which also occurs on ragwort, but has pale tibiae. The body length of Aphis jacobaeae apterae is 1.8-2.2 mm.

Adult apterae (see first picture below) of Aphis lambersi are blackish-green, dark mottled green, or (less commonly) purplish brown. Aphis lambersi resembles (but is not especially closely related to) other dark green species such as Aphis plantaginis and Aphis violae. The dorsal abdominal sclerotic pattern consists of a dark band across tergites 7-8, small postsiphuncular sclerites and dark intersegmental sclerites. Marginal tubercles on the aptera are prominent and mostly subconical in shape (see micrograph below). Leg hairs are short, mostly much shorter than the least width of the tibiae. The siphunculi are dark and relatively short being 1.06 - 1.75 times the length of the cauda. The body length of the Aphis lambersi aptera is 1.3 - 2.2 mm.

Aphis lamiorum cause downward leaf-curl on the shoot apices of dead-nettles (Lamium spp.), and dense colonies may also cause distortion and yellow blotching of the leaves (see first picture below). The adult apterae are dark blue-green to green, usually paler green on the posterior dorsum, and not wax covered, although there may be traces of wax on the dorsal cuticle (see second picture below). The antennal terminal process is 1.8-3.2 times the length of the base of antennal segment VI. The fused apical rostral segment (RIV+V) is 1.20-1.43 times the length of the second hind tarsal segment (HTII). The abdominal dorsum is membranous, with no sclerotic bands on tergites I-VI, but sometimes with small postsiphuncular sclerites. There are 0-5 marginal tubercles on abdominal tergites II-VI, with a mean of 1.4 (cf. Aphis frangulae which has 0-3 marginal tubercles on those tergites, usually 0). The siphunculi are dark and are 1.67-1.95 the length of the cauda. The body length of the adult aptera is 1.6-2.2 mm. Aphis lamiorum is a member of the Aphis frangulae complex, and difficult to distinguish from other members except by biology and host plant. Specimens can only be accepted as authentic Aphis lamiorum (as opposed to Aphis frangulae beccabungae on its secondary host) if leaf curl is present, and if samples are found early in the year (both were true with our specimens), or contain fundatrices or sexuales.

The aptera of Aphis lantanae is dark greenish-brown, and is not wax-powdered (see first picture below). Larger specimens have dark bands across tergites 6-8 and shorter bars on some or most of the other tergites. Their cauda is rather short and bluntly tapering. The body length of apterae is 1.5-2.1 mm.

Adult apterae of Aphis leontodontis (see first picture below) are greenish black with a brown head and no dark sclerotization on the dorsum (cf. Aphis picridicola, which has a marked dorsal abdominal sclerotic pattern). Assuming our pictures do indeed represent Aphis leontodontis (see note below), then there is a faint reddish-brown suffusion of the dorsum around the siphunculi, most noticeable in fourth instar immatures. The antennal terminal process is 2.1-2.6 times the length of base of antennal segment VI. Most hairs on antennal segment III are about 0.6 times the basal diameter of segment III, but a few hairs are frequently up to a little more than 1.0 times the basal diameter (cf. Aphis crepidis, Aphis hypochoeridis and Aphis taraxacicola, which have no long hairs on segment III). The abdomen has conspicuous, well-developed marginal tubercles on abdominal tergites II-IV (sometimes on V), as well as on tergites I and VII. The diameter of the marginal tubercle on tergite VII is 1.6-2.9 times the basal diameter of antennal segment III. The siphunculi are dark and are 1.4-1.8 times the length of the similarly dark cauda. The cauda is finger-shaped (cf. Aphis picridicola and Protaphis terricola, which both have a bluntly triangular cauda). The body length of adult apterae is 1.2-1.7 mm. Immature Aphis leontodontis are similarly coloured to the adult apterae with dark siphunculi.

Note: We cannot confirm our identification in this case as we obtained very few specimens (one adult aptera & a few immatures) for examination under the microscope - albeit the longest hairs on antennal segment III were 0.63 and 0.75 times the basal diameter of that segment. The only likely alternative identities of the aphid we found are Aphis crepidis or Aphis taraxacicola, but these have never previously been reported on Leontodon.

Adult apterae of Aphis longirostris (see first picture below) are dark green to dull bluish green and are not wax powdered. The abdominal dorsum is entirely membranous, except sometimes for a faint dusky spinal band on tergite 8. The fused apical rostral segment (RIV+V) is 1.45-1.63 times the length of the second hind tarsal segment, markedly longer than is the case with Aphis plantaginis. The siphunculi are 0.94-1.64 times the length of the cauda, somewhat shorter than those of Aphis plantaginis. All the hairs on the legs are shorter than the least width of the hind tibiae, most very much so. The body length of the adult Aphis longirostris aptera is 1.0-1.8 mm.

Adult apterae of Aphis loti (see first picture below) have a solid shiny black dorsal carapace, extending from the metanotum to abdominal tergite 6 inclusive (cf. Aphis lotiradicis which never has a solid dorsal carapace and varies from being entirely membranous to having transverse bands across all tergites). Note that the black dorsa of adults that have been stored in alcohol turn dark brown rather than black, because one of the dark pigments dissolves in alcohol, turning the alcohol deep purple. This has led many authorities to (wrongly) describe Aphis loti adults as being 'warm dark brown' in life, rather than shiny black; immatures (see second picture above) are, however, reddish brown. Abdominal tergites 2-6 may bear 0-2 (exceptionally 3-4) marginal tubercles (cf. Aphis lotiradicis which has a total of 6-7 marginal tubercles). The apical rostral segment is 0.8-1.1 times as long as the second hind tarsal segment. The siphunculi are roughly imbricate, often with a slight constriction just before the flange. The cauda is rather elongate finger-shaped, not uniformly tapering from base to apex (cf. Aphis craccivora, which has the distal part tapering). The Aphis loti aptera adult body length of is 1.2-2.1 mm.

Adult apterae of Aphis lugentis are dull blackish green to dark olive, or dark yellow-brown with a greenish tinge, with entirely dark appendages, often marked with sclerotic bands on tergites VII & VIII. There are 1-11 secondary rhinaria on antennal segment III, 7-11 on segment IV and 0-2 on segment V. The antennal terminal process is usually 1.6-2.1 times the base of antennal segment VI (cf. Aphis senecionis in mid-west USA, which has the terminal processs 1.35-1.55 times the base of that segment). The antennal hairs are pointed, 0.7-1.1 times as long as the basal diameter of antennal segment III. Marginal tubercles are only present on abdominal tergites I & VII (cf. Aphis jacobaea in Europe, and Aphis senecioradicis in western USA, which regularly have marginal tubercles present on tergites II-IV). The tibiae are entirely dark. The siphunculi are cylindrical, with flanges and imbrication, and are generally 1.2-1.5 times the caudal length. The cauda is elongated, nearly parallel-sided, with a tendency to constriction near its base. The cauda bears 6 or 7 hairs on either side, and is broadly rounded at the apex (cf. Aphis senecionis which has a cauda which tapers to an almost pointed apex). The body length of adult Aphis lugentis apterae is 2.0-2.8 mm.

First image above copyright Chieffo, second image copyright Krasik,third image copyright CBG Photography Group all under a Creative Commons License

Adult apterae of Aphis lupini are dusky olive to greenish black, shading to brown or black on the head. The legs are mostly light brown, and the siphunculi, anal plate, genital plate and cauda are dark. The antennae are rather uniformly dark, although sometimes the base of segment III is pale or dusky (cf. various polyphagous Aphis spp. whose segments III-V are mainly pale). The terminal process is less than twice as long as the base of antennal segment VI, and shorter than segment III. The rostrum reaches to between the second and third pairs of coxae. The apical rostral segment (RIV+V) is acute and quite long, 1.2-1.4 times the second hind tarsal segment (HTII) (cf. Aphis lupinehansoni in northwestern USA on Lupinus, which has RIV+V blunter, and about the same length as HTII). There are sclerotized dark dorsal bands on abdominal VII and VIII. The siphunculi are rather closely imbricated, cylindrical or slightly larger at bases, and with no polygonal reticulation (cf. Macrosiphum albifrons, Macrosiphum euphorbiae and Macrosiphum zionense on Lupinus, which all have a subapical zone of polygonal reticulation). The cauda is elongate, tapering, acute at the tip, and with only a slight constriction near the base; it is unusually hairy bearing 6-10 hairs on each side. The body length of adult Aphis lupini apterae is 2.0-3.0 mm. Newly deposited immatures are yellowish-brown; older immatures are green.

First image above copyright Andrew Jensen, second image copyright CBG Photography Group,
both under a Creative Commons License.

Adult apterae of Aphis maculatae are brownish black, with black siphunculi and cauda, and a paler head, legs and antennae. The body is marked with conspicuous patches of white wax powder on the lateral areas and along broken dorsal bands. The antennal tubercles are undeveloped. The antennae have numerous conspicuous setae as long as, or longer than, the width of the segments of the antennae, and antennal segment III has 15-22 secondary rhinaria over the distal 0.8 of its length. The tibiae have numerous long, fine hairs. Their siphunculi and cauda are black (cf. Aulacorthum solani & Macrosiphum euphorbiae, which also occur on the primary host, Cornus, but have pale siphunculi and cauda). The body length of adult Aphis maculatae apterae is 1.7-1.8 mm. Immatures (see second picture below) are light rusty brown, mostly covered with white wax powder patches with only the mid-dorsum of abdominal tergites II and III, and around the bases of the siphunculi, wax-free.

Images above by permission, copyright Claude Pilon, all rights reserved.

Adult apterae of Aphis mirifica (see picture of colony below) are mottled bluish-green or yellowish-green with black siphunculi. Their antennae are mainly pale, with only segments I, II, and distal portion of the antenna dark; the terminal process is 1.6-2.2 times the base of antennal segment VI (cf. Aphis frangulae, whose terminal process is 1.9-3.0 times the base; & cf. Aphis praeterita, which has a terminal process 3.3-4.7 times its base). The apical rostral segment (R IV+V) is 0.98-1.25 times the length of the second hind tarsal segment, and bears only 2 accessory hairs. The dorsum is membranous with narrow pale cross bars occasionally present on tergites VII and VIII. The abdomen has marginal tubercles on tergites I & VII, and frequently also on some of tergites II-VI (cf. Aphis frangulae, which very rarely has marginal tubercles on tergites II-VI). The siphunculi are imbricate, 0.9-1.4 times as long as the cauda. The siphunculi are less than twice as long as the base of antennal segment VI (cf. Aphis frangulae, which has the siphunculi at least twice as long as the base). The cauda is slightly constricted in the middle and bears 5-11 hairs. The body length of adult Aphis mirifica apterae is 1.2-2.2 mm.

Image above copyright Pierre Duhem on CC BY-NC creative commons licence.

The Aphis nasturtii aptera is rather bright pale green to yellowish-green in life and is not wax-powdered (see yellow aptera below in a mixed species colony of Aphis nasturtii and Aphis fabae). The abdominal dorsum is pale and membranous without dark bands or sclerites. The antenna barely exceeds half the body length. The siphunculi are usually rather pale sclerotic becoming a little darker towards the apex. The legs are dusky or rather pale - the apices of the tibiae are slightly darker as can be seen in the micrograph ventral view below. The body length of buckthorn - potato aphid apterae is 1.1-2.4 mm.

Adult apterae of Aphis neilliae (see first picture below) are dark olive-green or black (see first picture below), or sometimes reddish brown (see second picture below). The antennal tubercles are weakly developed. Their antennal hairs are long and fine, with the longest on antennal segment III being 2.3-3.5 times the basal diameter of that segment. Abdominal tergite VIII has a dark cross-band and bears 6-8 hairs. The siphunculi and cauda are uniformly dark. The siphunculi are tapering, being slightly swollen at the base. The cauda is short, tapering from a broad base to a rounded apex. The body length of adult Aphis neilliae apterae is 1.3-1.8 mm.

Images above by permission, copyright Claude Pilon, all rights reserved.

Aphis neogillettei live in curled leaf pseudogalls (see first picture below) on red-osier dogwood (Cornus sericea = Cornus stolonifera). Their adult apterae are dark olive-green with some red-brown mottling and a more or less dense covering of grey wax powder (see second picture below). The siphunculi, cauda and the apices of the antennae, femora and tibiae are dark (cf. Aphis nigratibialis, which has the tibiae uniformly dark). The antennal terminal process is 1.1-2.1 times the length of the base of segment VI. The hairs on antennal segment III of Aphis neogillettei are long, clearly exceeding the mid-diameter of that segment (cf. Aphis spiraecola, Aphis asclepiadis, Aphis gossypii, Aphis cornifoliae and Aphis impatientis, which all have hairs on that segment short, shorter or equal to the mid-diameter of that segment). Antennal segment III has no secondary rhinaria (cf. Aphis viburniphila, which has 15-23 secondary rhinaria on antennal segments III). The dorsal hairs on abdominal tergites I-VI are usually long, more than 40 µm. Abdominal tergite VIII has 4-6 hairs (cf. Aphis salicariae, which has 6-12 hairs on tergite VIII). The siphunculi are often curved outwards distally, and are about 5 times longer than their width at base. The cauda has 6-11 hairs. The body length of adult apterae is 1.0-1.4 mm. Immature Aphis neogillettei, especially fourth instar alatoid nymphs, have serial white wax markings on the dorsum.

Images above by permission, copyright Claude Pilon, all rights reserved.

Adult and and immature apterae of Aphis nerii are bright yellow-orange or lemon-yellow, with dark antennae. The antennal terminal process is 3.4-4.7 times the length of the base of the sixth antennal segment. The abdominal dorsum is entirely membranous. The legs including the hind tibiae are dark (cf. Aphis asclepiadis and several polyphagous Aphis species which have the hind tibiae pale for more than half their length). The rather long siphunculi and finger-shaped cauda are black, and the siphunculi are 1.7 - 2.7 times as long as the cauda. The body length of adult Aphis nerii apterae is 1.3-1.7 mm. The pictures below show live immatures on one of their prefered hosts, milkweed (an Asclepias species).

Both images copyright Alan Outen, all rights reserved.

Adult apterae of Aphis newtoni (see first two pictures below) range from pale reddish brown to dark greenish black. The terminal process is 2.8-3.6 times as long as the base of antennal segment VI. The fused apical rostral segment (RIV+V) is relatively short at 0.86-0.98 times as long as the second hind tarsal segment. The dorsal sclerotic pattern is similar to that of others of the Aphis fabae 'black aphid' group - namely transverse bands on tergites 7-8, marginal and postsiphuncular sclerites and some paired spinal sclerites on tergites 1-6. Marginal tubercles are protuberant and conspicuous on most or all abdominal tergites and are visible in the first picture of the live aphid below (cf. Aphis fabae, which has marginal tubercles present on tergites I & VII, but small or absent on tergites II-IV). The hairs on the femora and tibiae (see micrographs below of apterae in alcohol) are almost all much longer than the least width of the tibiae. The siphunculi are dark and are 0.92-1.55 times the length of the cauda. The dark cauda is tongue-shaped, much longer than its basal width (cf. Dysaphis tulipae, which has the cauda helmet-shaped, no longer than its basal width). The body length of the Aphis newtoni aptera is 1.78-2.15 mm.

Adult apterae of Aphis ochropus are yellow, yellowish-green or greenish yellow. The terminal process of antennal segment VI is 2.9-3.7 times the length of the base of that segment. The fused terminal segments of the rostrum (RIV+V) are 1.4-1.8 times the length of the second hind tarsal segment (HTII).The siphunculi are dark and are 2.00-2.86 times the length of the cauda. The cauda is pale (although in some of our specimens it appears dusky) with 7 hairs. The body length of the aptera of Aphis ochropus is 1.2-2.0 mm.

Adult apterae of Aphis odinae are usually grey-brown to reddish-brown (see first picture below) but, in east Asia, a dark green form also occurs. Both their siphunculi and cauda are dark. The antennal terminal process is 2.5-3.0 times as long as the base of antennal segment VI (cf. Aphis aurantii and Aphis citricidus, which have the terminal process 3.5-5.0 times as long as the base of antennal segment VI). A stridulatory apparatus is present, comprising a pattern of ridges on the ventro-lateral areas of abdominal sternites V and VI, and a row of short, peg-like hairs on the hind tibia. The siphunculi are only 0.4-0.6 times as long as the cauda (cf. Aphis aurantii which has the siphunculi 0.9 - 1.5 times as long as the cauda). The body length of adult Aphis odinae apterae is 1.3-2.4 mm.

First image above by permission, copyright Lu Zhaozhi, all rights reserved.
Second image above by permission, copyright Sunil Joshi & Poorani, J. Aphids of Karnataka (accessed 12/2/20).

Adult apterae of Aphis oenotherae (see first picture below) are pale yellowish green to dark green, and are lightly wax powdered. The ratio of the antennal terminal process to the base of antennal segment six (PT/base) ranges from 1.9-2.5 and is usually more than 2 (cf. Aphis holoenotherae for which that ratio ranges from 1.5-2.3 and is usually less than 2). The length of the terminal process is more than 0.23 mm (cf. Aphis holoenotherae where the length of the terminal process is less than 0.22 mm.). There are no marginal tubercles on abdominal tergites 2-6 (cf. Aphis grossulariae which has marginal tubercles on most of abdominal tergites 2-6). The siphunculi and cauda are completely pale (cf. Aphis nasturtiiwhich has the siphunculi darkened just at the apices). The body length of the adult Aphis oenotherae aptera is 1.5-2.0 mm.

Adult apterae of Aphis oestlundi are a more or less uniform pale green. The siphunculi are mainly pale, but with darker tips (cf. Aphis grossulariae, Aphis epilobiaria, Aphis oenotherae, which all have completely pale siphunculi, and cf. Aphis fabae, Aphis gossypii, Aphis spiraecola, all of which have dark or dusky siphunculi). The antennal terminal process is only 1.2-1.9 times the length of the base of antennal segment VI (cf Aphis praeterita, which has the terminal process 3.3-4.7 times the base of that segment). The apical rostral segment (RIV+V) is quite short at 1.35-1.70 times the length of the second hind tarsal segment (HTII) (cf. Aphis nasturtii, which has RIV+V less than 1.40 times the length of HTII). The anterior half of the subgenital plate has 4-6 hairs. The cauda and the anal plate are pale to slightly dusky. The body length of adult Aphis oestlundi apterae is 1.8-2.0 mm.

Both images above by permission, copyright Claude Pilon, all rights reserved.

Aphis origani is one of a group of species related to Aphis frangulae, but living monoeciously on Labiatae (see also Aphis passeriniana on Salvia and Aphis lamiorum on Lamium purpureum). Aphis origani lives on the stems and leaf-undersides of oregano (Origanum vulgare) causing a characteristic downward leaf-curl where they are often tented over with earth by attending ants (see first picture below). Adult apterae of Aphis origani vary in colour from greenish-yellow (see second picture below) to dark mottled green, with no waxing. Their antennal terminal process is 1.8-2.6 times the length of the base of antennal segment VI. The apical rostral segment (RIV+V) is 1.08-1.15 times the length of the second hind tarsal segment (HTII). The dorsal sclerotic pattern is variable but, at most, there may be marginal and postsiphuncular sclerites and bands on tergites VII-VIII. Hairs on the hind tibia vary from slightly shorter to slightly longer than the least-width of the tibia. The siphunculi are wholly dark and the cauda is dusky (cf. Aphis nasturtii, which have pale siphunculi with dark apices and a pale cauda). The siphunculi are 1.05-1.45 times as long as the cauda (cf. Aphis gossypii, whose siphunculi are 1.3-2.5 times the caudal length). The body length of adult apterae is 1.0-1.8 mm. Immature Aphis origani apterae are wax-free, and similarly coloured to their adults.

Adult apterae of Aphis paludicola (see top aphid in first picture below) are dark brown with a thick covering of grey-white wax. The hairs on antennal segment III are quite long and finely pointed, and 1.1-2.0 times the basal diameter of segment III (cf. Aphis euphorbiae, which has the longest hairs on antennal segment III 0.55-0.95 times its basal diameter). The siphunculi are 0.70-1.37 times longer than the cauda. The cauda bears numerous (28 or more) hairs. The body length of adult apterae is 2.3-2.7 mm.

Images above copyright Aimaina Hikari under a Creative Commons CC-Zero (public domain) licence.

For most of the year Aphis parietariae apterae range in colour from dark to light mottled green (see first picture below). In summer pale yellowish dwarf apterae may develop (see second picture below). There is a dusting of light grey wax on the dorsum. The antennal tubercles are weakly developed. The apterae have bands across tergites 7-8 in larger specimens but the dorsum is otherwise unpigmented. The siphunculi are blackish, much darker than any other sclerotic part of the body, although the siphunculi of dwarf apterae lighten somewhat near the bases. They are 1.0-1.5 times the length of the pale cauda, which bears 6-10 hairs. The body length of Aphis parietariae apterae is 0.9-1.7 mm.

Adult apterae of Aphis passeriniana (see first picture below) are mottled dull-green to dark-green in life, with a fairly marked wax bloom. The abdominal dorsum is wholly pale and membranous or, at most, with faint traces of dusky bands across tergites 7-8. The apical rostral segment (RIV+V) is conspicuously long and the second hind tarsal segment (HTII) is conspicuously short, giving a ratio of 1.54-2.02. Aphis passeriniana siphunculi range from pale to dark (see pictures of apterae below), and are tapering, rather long and stout. The siphunculi are 0.80 - 1.25 times the length of the relatively short and bluntly finger-shaped cauda. Hairs on the legs are rather short, mostly distinctly shorter than the least width of the hind tibiae. The body length of adult apterae ranges from 1.16-1.78 mm

Adult apterae of Aphis pawneepae have the head and thorax brown, and the remaining body portion reddish-brown, with a fine covering of white wax powder. The antennae are dusky-brown; the base of the third segment is lightest and apical antennal segments progressively darker. The legs are brown with knees and apical portions of femora and tarsi dusky. The siphunculi and cauda are dark. The antennae are either five- or six-segmented. When six segmented, the antennal terminal process is about twice as long as the base of antennal segment VI (cf. Longistigma caryae, which has the terminal process shorter than the base of that segment). Secondary rhinaria are absent. The rostrum reaches mid-way between the meso- and meta-thoracic coxae. The prothorax has a pair of very large marginal tubercles. The siphunculi are rather short, poorly imbricated without a flange, taper slightly towards the apex, and about 1.3 times the caudal length. The cauda is more or less triangular, with about 20 hairs. The body length of adult Aphis pawneepae apterae is 1.5-1.7 mm.

Image above copyright Even Dankowicz, under a Creative Commons Attribution License.

Adult apterae of Aphis pentstemonicola are green (see first picture below), greenish yellow, or light yellow (see second picture below), with a dark green patch in the mid-dorsum (the dark green colour is in the internal tissue, so is lost in clarified mounts) (cf. Aphis asclepiadis, which does not have a dark green mid-dorsal patch). The head and thorax are dusky, and there are traces of mid-dorsal bands on tergites VI, VII & VIII. There is a large dusky patch on the dorsum on the inside of each siphunculus (cf. Aphis asclepiadis, which does not have dusky patches, but may have a dark narrow sclerite by each siphunculus). The antennae are dusky or dark, apart from the basal part of segment III which is pale. The number of secondary rhinaria on antennal segment III is extremely variable, varying from 0-18, leading to suggestions that more than one species might be involved here (see note below). There are marginal tubercles on the prothorax and abdominal tergites I and VII. The siphunculi, cauda, anal plate and genital plates are dark, and the legs are pale to dusky, with the tarsi and tips of tibiae blackish. The siphunculi are cylindrical, coarsely imbricated and with a flange. The anal plate is slightly produced on the ventral margin. The cauda is bluntly triangular with only a slight tendency to constriction near the base, and bearing three hairs on each side. The body length of adult Aphis pentstemonicola apterae is 1.8-2.0 mm

First image above copyright Andrew Jensen under a cc by-nc-sa licence.
Second & third images above, copyright Jesse Rorabaugh no rights reserved.

The fundatrix of Aphis phaceliae (see pictures below) has the posterior dorsum pale yellowish-green shading anteriorly to pale green or apple-green mottled with darker bluish-green, and a pale yellowish cauda. Apterous viviparae are rusty yellow on the head, with rest of the dorsum yellowish green or canary-yellow mottled with green anteriorly. The dorsum has no dark transverse intersegmental sclerites (cf. Myzus ornatus, which has conspicuous dark transverse intersegmental sclerites). The antennae are shorter than body length (cf. Illinoia phacelia which has antennae much longer than body length). They have weakly developed antennal tubercles, and secondary rhinaria are occasionally present on antennal segment III. The apical rostral segment (RIV+V) is 0.15 mm in length, 1.5-1.6 times the length of the second hind tarsal segment (HTII); it is longer than the cauda and bears 4-5 hairs. The prothorax and abdominal tergites I & VII have marginal tubercles. The siphunculi are dark (or sometimes pale with dark tips, given these pictures), and are cylindrical or somewhat tapering distally (cf. Myzus ascalonicus and Myzus persicae, which have slightly or moderately swollen siphunculi). The cauda is elongate, parallel-sided, with a light constriction or neck near the base, and bears 3 hairs on each side.

Images above copyright Andrew Jensen under a cc by-nc-sa licence.

Colonies of Aphis picridicola live basally on the rosette and root collar of hawkbit (Leontodon taraxacoides) where they are tented with sand or soil particles by attending ants (see first picture below). Adult apterae of Aphis picridicola are bluish-grey, bluish green or pale green with a greyish wax bloom (see second picture below). The antennae normally have 6 segments, although in some smaller individuals segments III and IV are more-or-less fused. The antennal terminal process is 1.5-1.9 times the length of the base of antennal segment VI. The rostrum is rather long with the fused apical rostral segment 1.21-1.36 times the length of the second hind tarsal segment. There is a marked dorsal abdominal sclerotic pattern characterised by a tendency for the dark intersegmental sclerites to enlarge, especially on tergites IV-V where they form large spreading dark patches just in front of the siphuncular bases. Spinal bands and marginal sclerites are also present on most segments. Marginal tubercles on abdominal segments I and VII are rather large. The siphunculi are rather short, only 0.9-1.11 times the length of the short subtriangular cauda. The body length of adult Aphis picridicola apterae is 1.4-2.1 mm.

The alate Aphis picridicola (not pictured) has large marginal sclerites on tergites II-IV but not on V, no postsiphuncular sclerites, short bands on tergites VII-VIII, and two distinct series of dark pleural intersegmental muscle sclerites, the outer series lying very near the marginal sclerites. There may also be small spinal sclerites on tergites I-VI. Immatures (see third picture above) are greenish with or without faint dark intersegmental markings.

Adult apterae of Aphis pilosellae are pale to dark green. Immature aphids are paler (see pictures below). Large apterae have dusky bands across tergites 7-8 or 6-8; small apterae have only faint dusky bars on 7-8. The most distinctive character of Aphis pilosellae is the long apical rostral segment which is longer than antennal segment IV or V. The marginal tubercles on abdominal segments 1 and 7 are rather large. The siphunculi are 0.80 to 1.25 times the length of the cauda, which is tapering with very strongly incurved hairs. The body length of the Aphis pilosellae aptera is 1.02-1.54 mm.

Aphis podagrariae induces characteristic tightly bunched leaf-curls on its main host, ground elder (Aegopodium podagraria, see first picture below). Adult apterae of Aphis podagrariae are black or blackish-green sometimes with areas of reddish-brown suffusion (see second picture below), and are usually without wax. Their antennae are 6-segmented with a terminal process 2.1-2.6 times as long as the base of antennal segment VI. The apical rostral segment (RIV+V) is 1.13-1.31 times the length of the second hind tarsal tarsal segment (HTII) (cf. Aphis fabae sstr., which has RIV+V 0.88-1.06 times the length of HTII). The degree of abdominal sclerotization is variable. Stroyan (1984) reported that it varied with the size of the aphid, with larger adults having a complete series of bands over the thorax and abdomen, and smaller ones having bands only on tergites VII & VIII, but most of the specimens we have found only have bands on VII & VIII regardless of size. There are usually no marginal tubercles on tergites II-IV (cf Aphis solanella, for which about 50% of individuals have one or more marginal tubercles on tergites II-IV). The length of the hairs on the tibiae and femora are up to about twice the least width of the tibiae. The siphunculi are 0.75-1.45 times as long as the cauda (cf. Aphis brohmeri, which has siphunculi 1.26-1.58 times the length of the cauda). The length of adult Aphis podagrariae apterae is 1.44-2.47 mm. Immatures, especially third and fourth instars, often have small pleural white wax spots (also see second picture below), and younger instars may have a more general wax dusting.

Adult apterae of Aphis polygonata are red-brown (see first picture below) to dark brown to black. The antennal terminal process is 1.7-2.6 times the length of the base of segment VI. The abdominal dorsum is membranous without any banding of the tergites, but there are small dark intersegmental muscle sclerites and rather strong reticulation of the cuticle (which is clearly visible in the first image below). The siphunculi of Aphis polygonata are conspicuously pale and are very short and strongly tapering, being only 0.63-0.85 times the length of the cauda. The cauda is of the same colour as the siphunculi or darker and is bluntly tapering. The body length of adult apterae is 1.6-1.2 mm.

Third image above copyright Mihajlo Tomić, all rights reserved

The Aphis pomi aptera (below first) is bright apple green or yellow green and is not wax-powdered. The abdominal dorsum is pale and usually entirely membranous, although rarely a small sclerite or short bar may occur on the spine of tergite 5. The fused last two rostral segments are more than 120 μm in length and marginal tubercles are present on abdominal tergites 2-4 (the latter two characters distinguish Aphis pomi from the very similar invasive Aphis spiraecola). The siphunculi and cauda are conspicuously blackish. The cauda has 10-19 hairs (rarely less than 13). The body length of an adult aptera is 1.2-2.2 mm.

Adult Aphis praeterita apterae are lemon yellow to greenish yellow (see two pictures below). Their abdominal dorsum is membranous with little or no sclerotization. Marginal tubercles are small (barely visible in the micrograph below right), those on tergites 1 and 7 being distinctly smaller than the adjacent spiracular plates. The tapering siphunculi are apically dusky and have regular imbrication. They are 1.29-1.95 times the caudal length. The cauda is slightly dusky and finger-shaped. The body length of adult Aphis praeterita apterae is 1.44-2.47 mm.

Adult Aphis pseudocomosa apterae usually have a solid and extensive shiny black dorsal sclerotic shield with reticulation incorporating all the marginal sclerites (see first picture below). Smaller specimens sometimes have a more broken pattern. Unsclerotized parts are a dark warm brown. The longest hair on the third antennal segment is 0.67-1.38 times the basal diameter of that segment (cf. Aphis craccivora on which the longest hair on the third antennal segment is usually 0.37-0.75 times the basal diameter of that segment; cf. Aphis loti on which the longest hair on the third antennal segment is usually 0.40-0.71 times the basal diameter of that segment). Marginal tubercles are variable in size and distribution - when present those on tergites 2-6 are small (cf. Aphis coronillae on which there are 4-10 protuberant marginal tubercles on tergites 2-6). The cauda is tapering. Adult aptera body length is 1.52-2.29 mm. Immature Aphis pseudocomosa (see second picture below) are reddish brown to magenta with a greyish wax bloom.

Adult apterae of Aphis punicae are yellowish-green, green or grey-green with siphunculi pale green to brown with darker apices (but wholly dark in spring) and a pale cauda (cf. Aphis achyranthi, Aphis aurantii, Aphis craccivora, Aphis fabae and Aphis spiraecola, which all have both the cauda and siphunculi very dark). All the segments of antennae are pale, except for the base of segment VI and the terminal process which are darkened. The antennae are almost half as long as the body, with the terminal process about twice as long as the base of antennal segment VI. The rostrum does not reach the third pair of coxae. There are marginal tubercles on the pronotum and on abdominal tergite I. The legs are pale, with tarsi dusky to dark. The siphunculi are 1.1-1.5 times the caudal length. (cf. Aphis gossypii, which usually has siphunculi more than 1.5 times the length of the cauda). The cauda is 0.35-0.44 times as long as the width of the head across the eyes, and has 7-9 hairs (cf. Aphis gossypii, which usually has 4-7 hairs on its cauda). The anal plate is dark. The body length of adult Aphis punicae apterae is 1.0-1.7 mm.

First two images above by permission, copyright Sunil Joshi & Poorani, J. Aphids of Karnataka (accessed 12/2/20)
Third image copyright Stavros Apostolou under a under a Creative Commons licence.

Adult apterae of Aphis rubicola (see two pictures below) are very small, yellowish to green aphids, with mainly pale appendages. The spring form has 6-segmented antennae, but the summer dwarfs have 5-segmented antennae (cf. Aphis rubifolii, which always have 5-segmented antennae). The antennal terminal process is 2.0-2.6 times as long as the base of antennal segment VI. The apical rostral segment (RIV+V) usually has 3-4 accessory hairs. The prothorax and abdominal tergites I & VII usually have marginal tubercles. The dorsal body hairs are mostly very long, the longest being 2.5-4.0 times the basal diameter of antennal segment III (cf. Aphis rubifolii, which has much shorter body hairs). The siphunculi taper from base to flange and are pale or dusky, and sometimes dark at their apices. Abdominal tergite VIII has 3-5 hairs, and the cauda usually has 10-12 hairs. The body length of the Aphis rubicola spring form is 0.9-1.2 mm, with summer dwarfs only 0.6-0.9 mm in length.

First image above by permission, copyright Claude Pilon, all rights reserved.
Second image copyright CBG Photography Group under a Creative Commons License.

Aphis rubifolii lives in curled-leaf pseudogalls (see first picture below) of various species of blackberry (Rubus species). The adult apterae are pale yellow, mottled to a greater or lesser extent with green (see second picture below). Their appendages are mainly pale, but the tarsi and apices of the siphunculi are dusky or dark. The antennae of Aphis rubifolii are 5-segmented (cf. Aphis rubicola, which usually have 6-segmented antennae - except for the summer dwarfs of that species which have 5-segmented antennae). The antennal terminal process is 1.6-2.6 times the length of the base of antennal segment VI (cf. Aphis ruborum, which has the terminal process 2.5-3.6 times the length of the base of antennal segment VI). The cauda has 7-11 hairs (cf. summer dwarfs of Aphis ruborum, which have 4-7 hairs on the cauda). The body length of adult Aphis rubifolii apterae is 0.9-1.4 mm.

Images above by permission, copyright Claude Pilon, all rights reserved.

Aphis ruborum apterae (see first picture below) are commonly dark blue-green in spring and pale yellow-green in summer. Dwarf apterae (0.8-1.0 mm) occur in late summer. The abdominal dorsum is mostly pale and membranous. The siphunculi are pale but with dusky bases and apices, and 1.1-2 times the length of the cauda. The antennae and legs are pale. The body length of Aphis ruborum apterae usually varies from 1.1-2.2 mm.

Aphis rumicis rolls and crumples the leaves of its host to form pseudogalls, (see first picture below) before later in the year moving up stems and into the inflorescences (cf. Aphis fabae which does not roll the leaves). The apterae (see second picture below) are coal-black to very dark greenish-brown. Their antennae are pale near their bases but are darkened from the middle of segment III to their tips. The dorsum typically has well marked bands across tergites 6-8 as well as fragmented bands on tergites 1-5 (these bands are difficult to see in live specimens). The hairs on their hind legs are all much longer than the least width of the tibiae. The black siphunculi are 0.89-1.35 times the length of the black cauda. The body length of Aphis rumicis is 2.05-2.77 mm.

Aphis salicariae apterae are reddish brown with a marked wax bloom making the aphids appear grey or pinkish (see first picture below). The mid-dorsum of the Aphis salicariae aptera is more or less membranous but there are small postsiphuncular and marginal sclerites, dark intersegmental muscle sclerites and transverse bands across tergites 6-8. The siphunculi are gently to rather strongly curved outwards, and the cauda is short and bluntly tapering. The body length of Aphis salicariae apterae is 1.8-2.3 mm.

On their primary host (elder), Aphis sambuci apterae (see first picture below) are very variable in colour from dark green through to yellowish brown; on their secondary host (e.g. root collar of dock) Aphis sambuci are usually dark green. Adults and immatures often have white waxy stripes acros the sides of the abdominal segments. Antennae, siphunculi and legs blackish on the primary host and brownish in root colonies. The dorsal abdominal sclerotic pattern comprises small marginal and postsiphuncular sclerites, dark intersegmental muscle sclerites and variably complete transverse bands across tergites 6-8. Tergites 1-4 and and 7 have marginal tubercles (visible if you expand the images below) between their dark marginal sclerites. The cauda is dark and bluntly tapering. The body length of adult Aphis sambuci apterae is 2.0-3.5 mm.

Colonies of Aphis sanguisorbae can be found on the stem bases and surface roots of burnets (Sanguisorba spp.) which have been ant-tented with chalk fragments (see first picture below). Adult apterae are blackish brown, sometimes with copper and red-brown hues on the posterior tergites. The newly moulted aphids are very shiny, but as they age they develop a slight wax bloom giving them a matt appearance. The wax bloom is most apparent on immature Aphis sanguisorbae. The dorsal cuticle usually has a distinct reticulation. The dorsal abdominal pattern is confined to narrow dark bands across tergites 7-8 and small dark intersegmental muscle sclerites. The siphunculi are dark, more or less cylindrical and with hardly any apical flange. The cauda is short, broadly tongue shaped and often very pale. Hairs on the legs are blunt and mostly short.

Adult apterae of Aphis schinifoliae are dark reddish-brown with paler brown blotches (see large aphids in both pictures below). The femora, tibiae and antennae are pale basally, but dark apically. The cauda is dusky, but the siphunculi are pale (cf. Aphis schinivora & various polyphagous aphids on Schinus which all have dark siphunculi). Antennal tubercles are undeveloped. The antenna has a short terminal process, about 1.4 times as long as the base of antennal segment VI. Well-developed marginal tubercles are usually present on abdominal tergites II-VI, as well as I and VII. The siphunculi are rather short and almost flangeless. Body length of adult Aphis schinifoliae apterae is 1.4-1.7 mm. Young immatures are bright orange, darkening as they pass through the larval instars.

First image above copyright Flavio Martinez under a Creative Commons License.
Second image by permission copyright Ortego, Nieto Nafria & Mier (2007) all rights reserved.

Adult apterae of Aphis schinivora are shiny black with partially white legs (see clarified slide mount of aptera in first picture below). The antennae are 6-segmented, but antennal segments III & IV sometimes coalesce. Antennae are 0.47-0.67 times the body length, and lack secondary rhinaria. The rostrum reaches or overlaps the hind coxae, with the apical rostral segment 1.0-1.3 times the second hind tarsal segment. Dorsal abdominal pigmented sclerotic areas are very variable, from minimal coverage to broken large spinal-pleural patches on tergite IV, small patches on tergites I-III & V-VI and bars on tergites VII-VIII. There are large marginal tubercles on the prothorax and tergite I, and numerous conspicuous marginal tubercles on other tergites. The siphunculi are dark brown to black (cf. Aphis schinifoliae on other Schinus spp., which has pale siphunculi). Siphunculi are cylindrical, and rather short, only 0.3-0.7 times the cauda, with a small apical flange (cf. the polyphagous species Aphis aurantii, Aphis craccivora, Aphis fabae, Aphis gossypii & Aphis spiraecola, whose siphunculi are more than 0.7 times the cauda). The cauda is brown to dark brown, more pigmented on the margins and with 4-8 hairs. The body length of adult Aphis schinivora apterae is 0.9-1.4 mm.

Aphis schneideri apterae are dark bluish green to blackish green with distinct wax powdering. The hairs on the third antennal segment are long, acute and 2.0-3.1 times the basal diameter of that segment (cf. Aphis grossulariae which has those hairs only 1.0-1.5 times the basal diameter of that segment). The dorsal abdominal sclerotic pattern of Aphis schneideri is absent or limited at most to dusky bands across tergites 6-8. The abdominal marginal tubercles are very prominent, subconical and are often present on all segments from 1-7 inclusive. Their siphunculi and legs are pale.The cauda is short and blunt. The body length of apterae is 1.7-2.3 mm.

Aphis sedi apterae are small and dark green to blackish green with no wax powdering. The antennal terminal process of Aphis sedi is 1.6-2.3 times the base of the sixth antennal segment (cf. Aphis gossypii which has the terminal process 2.1-3.2 times the base of the sixth antennal segment). The fused apical rostral segment (RIV+V) of Aphis sedi is 1.04-1.20 times the length of the second hind tarsal segment (HT2) (cf. Aphis gossypii where RIV+V is 1.00-1.57 times the length of HT2.) Their dorsal abdominal sclerotic pattern is limited at most to dusky bands across tergites 7-8. The siphunculi of Aphis sedi are dark, but the antennae and legs have conspicuous pale sections (see first picture below). The siphunculi are 0.8-1.5 times the length of the cauda which is short, blunt and rather dark, only a little paler than the siphunculi (cf. Aphis gossypii where the cauda is usually pale/dusky, markedly paler than the siphunculi). The body length of Aphis sedi apterae is 1.0-1.6 mm.

Adult apterae of Aphis serpylli are rather dark blue-green, with a very slight wax bloom (see first two pictures below). The dorsal abdominal sclerotic pattern is usually limited to bands across tergites 7-8, but is lost in small individuals. Marginal tubercles are present on abdominal tergites 1 & 7, but not on tergites 2-6. Hairs on the legs are mostly rather short, but caudal hairs are long. The siphunculi have a marked flange and are 0.54-1.33 times as long as the cauda. The adult apterae are small with a body length of only 1.00-1.38 mm.

Adult apterae of Aphis solanella are dull black or blackish brown, occasionally with white pleural transverse wax stripes. The longest hair on antennal segment III is 0.6-1.9 times the basal diameter of antennal segment three, in most specimens shorter than 1.5 times the basal diameter. The third antennal segment of the adult Aphis solanella aptera is 11-20 times longer than the longest hair borne upon it (c.f. Aphis fabae fabae & Aphis fabae cirsiiacanthoidis where the third antennal segment is 4-9 times longer than the longest hair borne upon it). The dorsum has variable dark markings usually with dark sclerotic bands on the pronotum, mesonotum and abdominal tergites 7 and 8, and small dark marginal sclerites. They have marginal tubercles on abdominal segments VI and usually also on I (see first picture below), and sometimes smaller ones on some of the segments II-IV.

Adult apterae of Aphis spiraecola are bright greenish yellow to apple green. The abdominal dorsum is pale and usually entirely membranous. The fused last two rostral segments are less than 120 μm in length (cf. Aphis pomi which has the fused last two segments more than 130 μm in length). Marginal tubercles are restricted to abdominal tergites 1 & 7, with none present on abdominal tergites 2-4 (cf. Aphis pomi which has marginal tubercles on tergites 2-4 ). The femoral hairs are long and fine, the longest of them being longer than the diameter of the femur at its base. The siphunculi and cauda are black. The cauda usually has less than 12 hairs (7-15) (cf. Aphis pomi on which the cauda usually has more than 13 hairs (10-19)). The body length of an adult Aphis spiraecola aptera is 1.2-2.2 mm.

Adult apterae of Aphis spiraephaga (see large aphid in centre of first picture below) are dark greyish brown, with transverse dorsal bands of greyish-white wax (cf. Aphis spiraecola, which is green or yellowish green). The siphunculi and cauda are equally dark (cf.Aphis gossypii, which has the cauda paler than the siphunculi). The antennae & legs are also dark, except for antennal segment III, and the major part of the tibiae. The antennae are 6-segmented, 0.5-0.8 times the body length, with a terminal process 1.6-2.3 times the base of antennal segment VI. The longest hair on antennal segment III is 0.5-0.9 times the basal diameter of that segment (cf. Aphis fabae and Aphis solanella, which both have the longest hair 1.0-3.4 times the basal diameter), and there are no secondary rhinaria. The rostrum reaches to, or behind, the middle coxae, and the apical rostral segment (RIV+V) is 0.7-0.9 times the second hind tarsal segment (HTII). The dorsum has a very variably developed pattern of sclerotization. The abdomen has marginal tubercles on segments I & VII, rarely with smaller ones on segments II-IV. The siphunculi are scaly, 0.7-1.1 times the caudal length (cf. Aphis spiraephila in North America, which has short siphunculi, only 0.4-0.5 times the cauda). The cauda has 7-17 hairs. The body length of adult Aphis spiraephaga apterae is 0.9-2.0 mm. Young immatures are usually light reddish brown, darkening as they mature, and with wax bands.

Images above by permission, copyright Dr László Érsek, all rights reserve

Adult apterae of Aphis spiraephila (see first picture below) vary in colour from hazel to chestnut-brown. They are coated with powdery white wax. The head, siphunculi and cauda are dusky or dark, but their antennae and legs are mainly pale. The antennal terminal process is 1.3-1.5 times the length of the base of antennal segment VI. Abdominal tergites I and VII bear marginal tubercles. The siphunculi are quite short, only 0.4-0.5 times as lomg as the cauda (c.f. Aphis spiraecola, which has siphunculi more than 0.6 times the caudal length). The cauda bears 13-16 hairs. The body length of adult Aphis spiraephila apterae is 1.3-1.7 mm.

Both images above by permission, copyright Claude Pilon, all rights reserved.

Adult apterae of Aphis symphyti (see two pictures below) are dark green to pale yellowish green, more rarely lemon yellow. They are not covered in wax. Their antennae are 6-segmented with the terminal process 1.7-3.0 times as long as the base of antennal segment VI. The apical rostral segment (RIV+V) is 0.12-0.16 mm in length (cf. Aphis gossypii, which has RIV+V 0.075-0.135 mm long). The apterae have no dark markings anterior to the siphunculi, but may or may not have bands across tergites VII-VIII (cf. Aphis fabae, which usually has some dark markings anterior to the siphunculi, and always has well developed dark cross bands on tergites VII & VIII). There are marginal tubercles on tergites I and VII which are very variable in size. The femoral hairs are similarly variable in length, and may be less than or more than the least width of the hind tibiae. The siphunculi are uniformly dark, and are 1.2-1.7 times the length of the cauda. The cauda, which bears 5-8 hairs, is usually dusky, but in spring is sometimes black. The body length of adult Aphis symphyti apterae is 1.3-2.0 mm.

Note: This is one of the 'small frangulae' species much referred-to by Stroyan (a group of perhaps 10 species closely resembling Aphis frangulae, including Aphis lamiorum, Aphis parietariae, Aphis praeterita, Aphis ruborum, Aphis urticata). Aphis symphyti is difficult to distinguish from other members of this group on morphological grounds but, in most cases, differs in host. There are however some generalists in the group, most importantly Aphis gossypii, which is thought to occur on various genera in the Boraginaceae. Working solely from these photographs we cannot therefore be 100% certain of the identity of the aphids pictured here - given the host they are most likely Aphis symphyti, but could be Aphis gossypii.

First two images above, by permission copyright Dirk Baert, all rights reserved.
Third image above above, by permission copyright Marko Šćiban, all rights reserved.

Aphis taraxacicola apterae are mottled dark green (see first picture below), and are not wax powdered. Their siphunculi are dark and the cauda is dusky. The terminal process of the sixth antennal segment is 2.1 to 2.8 times the length of the base of that segment. The abdominal sclerotic pattern varies from being heavily marked with dark intersegmental muscle sclerites and small marginal and postsiphuncular sclerites across tergites 7-8 to almost complete lack of any dark pigmentation. Abdominal marginal tubercles are rather large and prominent. The hairs on their legs are short with all femoral hairs shorter than the least width of the hind tibiae. Aphis taraxacicola siphunculi are 1.2 to 2.4 times the length of the cauda. The body length is 1.6 to 2.02 mm.

Adult apterae of Aphis thalictri are bluish grey to greenish brown, with often heavy wax deposits in transverse bands across the dorsum. The frons has weakly developed antennal tubercles. The antennae are 6-segmented, about 0.6-0.7 times body length, and with the terminal process 1.5-1.7 times the base of antennal segment VI. The longest hair on antennal segment III is 0.7-1.2 times the basal diameter of that segment. There are no secondary rhinaria on the aptera. The rostrum does not reach behind the hind coxae. The dorsum is membranous, with a narrow dark cross bar on tergites VII and VIII, and intersegmental muscle sclerites. There are small conical marginal tubercles on the prothorax and abdominal segment VIII, and flat marginal tubercles on tergite I. The siphunculi are nearly cylindrical, wrinkled and very short, only about 0.02 times body length and 0.3-0.4 times the cauda. The cauda is rather broad, more or less triangular with an acute apex, hardly longer than its basal width, and with 9-12 hairs (cf. Longicaudus trirhodus, which has the cauda finger-like and much longer than its basal width). The body length of adult Aphis thalictri apterae is 2.0-2.8 mm.

First image above copyright Gennadiy Okatov; second image copyright Vyacheslav Yusuppov,
both under a cc by-nc-sa licence.

Adult apterae of Aphis tormentillae (uppermost aphid in picture below) are rather small and very dark blackish green, appearing black in life. The antennae of the adult aptera often only have five segments. The dorsal abdominal pattern of Aphis tormentillae aptera is confined to bands across tergites 7-8, small dark intersegmental muscle sclerites and sometimes rudimentary marginal and postsiphuncular sclerites.There are small protuberant marginal tubercles on abdominal tergites 1 and 7. Their siphunculi are short and stout, 0.64-1.00 times the length of the cauda. The cauda is finger-shaped and dark like the siphunculi. The body length of the Aphis tormentillae aptera is 1.00-1.67 mm.

Apterous Aphis tripolii are apple green with a dusky head and no wax powdering (see first picture below). The abdominal dorsum is entirely pale. The siphunculi are yellowish with dusky apices, and are 0.86-1.22 times the length of the cauda. The cauda is dusky with 5-9 hairs. The body length of Aphis tripolii is 1.3-2.45 mm.

The apterae of Aphis ulicis are very dark blackish green, but may appear greyish because of strong wax powdering (see first picture below). Their sclerotized dorsal abdominal shield may appear shiny black. The size and solidity of the dorsal shield in apterae is very variable - it may cover a large area or be greatly reduced or it may break up into irregular segmental bars or sclerites (as shown in the first micrograph below). Marginal tubercles are present on abdominal segments I and VII. The apical rostal segment is slender (more than 3 times as long as width at base) and pointed. It is narrower at its base than is the case in the very similar Aphis cytisorum. The siphunculi are dark and are 0.9-1.6 times as long the cauda. The cauda is also dark, but legs and antennae are mostly pale. The body length of Aphis ulicis apterae is 1.3-2.4 mm. Immatures (see second picture below) are usually more heavily waxed than the adults.

Aphis ulmariae live in pseudogalls comprised of the more or less curled terminal leaves of meadowsweet (Filipendula ulmariae, see first picture below). Adult apterae are generally described as mottled dark green in life but (as the second picture below shows) some are yellow mottled with green, similar to the colour variation shown by its closest relative Aphis ruborum. They are not wax coated. The antennal terminal process is 2.0-2.6 times as long as the base of antennal segment VI (cf. Aphis ruborum, which has a terminal process 2.5-3.6 times the length of the base of that segment). The apical rostral segment (RIV+V) is 1.13-1.45 times the length of the second hind tarsal segment (HTII). The dorsal abdominal sclerotic pattern may be absent, or reduced to dusky bands on tergites VII & VIII. The siphunculi are rather pale dusky, darkening slightly from base to apex, and 1.15-2.00 times the length of the cauda. The cauda is bluntly subtriangular to elongate tongue-shaped. The usual body length of adult Aphis ulmariae apterae is 1.4-2.4 mm, but summer dwarfs are only 1.1-1.4 mm.

Images above by permission copyright Mark Wilson, all rights reserved.

Adult apterae of Aphis umbrella (see first picture below) are pale green or yellowish green usually mottled with darker green. The abdominal dorsum in apterae is quite pale. The siphunculi in apterae are usually pale, often becoming slightly dusky at the apex. The siphunculi are 1.53 to 2.06 times the length of the cauda. The body length of Aphis umbrella apterae is 1.7-2.3 mm.

Aphis urticata is a small to medium size aphid. Early generations of the dark green nettle aphid are dark bluish-green (see first picture below) with no wax covering. Later generations of dwarf summer apterae become pale yellowish. The abdominal dorsum is either unsclerotized or rarely with rather narrow dusky bands across tergites 7-8. The longest posterior hairs on the femora, and the longest tibial hairs, are always much longer than the least width of the tibiae. The pale tapering siphunculi are usually slightly dusky, and are 0.90-1.78 times the length of the cauda. The tongue shaped cauda is also pale. The body length of adult Aphis urticata apterae is 1.7-2.2 mm.

Adult apterae of Aphis vaccinii (see largest individuals in first picture below) are very dark blackish-green, appearing bluish-black from the presence of a fine wax bloom. Antennal segments III, IV (except apex) and often base of V are pale, with the remainder black. The femora, tibial apices, tarsi, siphunculi and cauda are all black, with just the mid-tibia pale. The antennae are 0.6-0.7 times the body, with the terminal process 2.2-3.2 times the base of antennal segment VI. The longest hair on segment III is 1.2-2.4 times (Stroyan gives 0.8-1.0 ×) the basal diameter. The rostrum reaches the hind coxae, with the apical rostral segment 0.93-1.12 times the second hind tarsal segment. The abdomen has intersegmental muscle sclerites, marginal and postsiphuncular sclerites and often dorsal cross bars or small dorsal sclerites. There are marginal tubercles on tergites I & VII, often with smaller ones on other segments. The siphunculi are imbricated, rather short, about as long as (0.8-1.2 times) the cauda, with a small flange. The cauda is tongue-shaped with 8-16 hairs. The body length of adult Aphis vaccinii apterae is 1.3-2.0 mm (cf. Aphis fabae, which is usually more than 2 mm in length, but can be smaller). Immatures (see second picture below) resemble the adult apterae, but with a slightly heavier wax deposit.

First & third images above by permission, copyright Linda Kjaer-Thomsen, all rights reserved;
Second image, copyright Hans Henrik Bruun, under a creative common licence.

Adult Aphis vandergooti apterae (see first picture below) are dark blue-green (or rarely yellow), with blotchy paler areas and no wax powdering. There is usually no dorsal abdominal sclerotic pattern, or there may be narrow bands across tergites 7-8. Marginal tubercles are large and conspicuous but rather flattened (best seen in the micrographs of preserved specimens below). Leg hairs are all very short, much shorter than the least width of tibiae. The siphunculi are tapering, usually widening slightly at the apex with a very small apical flange. The siphunculi are 1.93-2.57 times the length of the cauda. The body length of Aphis vandergooti apterae is 1.4 to 2.0 mm. Immatures (see second picture below) are a dappled light green.

Adult apterae of Aphis varians (see two pictures below) are dark blue-green to greenish-brown or orange-brown with a rather uniform powdering of wax; the siphunculi are pale and the cauda is mainly dark or dusky. The hairs on antennal segment III are very long, fine & wavy, 1.8-4 times the basal diameter of that segment (cf. Aphis epilobii and Aphis oenotherae, both in Europe & USA, which have those hairs only 1-2 times the basal diameter). The antennal terminal process is 1.5-2.0 times the base of antennal segment VI (cf. Aphis epilobii & Aphis oenotherae, which both have the terminal process more than 2 times the base of that segment). The apical rostral segment (RIV+V) has 6-12 accessory hairs (cf. Aphis praeterita, Aphis frangulae, Aphis asclepiadis & Aphis gossypii, which all have only 2 accessory hairs on RIV+V). There are marginal tubercles on abdominal tergites I & VII, but tergites II-V only sporadically have small marginal tubercles (cf. Aphis schneideri in Europe & Asia, which has well-developed marginal tubercles on all abdominal tergites other than VI). The siphunculi are milky-white, with dusky tips, and the cauda is dark or dusky. The body length of adult Aphis varians apterae is 1.0-2.2 mm. Immatures are dull green.

First image above copyright M. Alex Smith, CBG Photography Group,
second image copyright Andrew Jensen, both under a cc by-nc-sa licence.

The original description of adult apterae of Aphis veratri states they are black, not shining, with a slight greyish wax bloom. They have since been redescribed as dark greenish-brown. Our (sadly rather blurred) pictures suggest they are somewhat variable in colour varying from reddish-brown to black. The antennal terminal process is 2.3-3.4 times the length of the base of antennal segment VI. Antennal segment III has 8-12 hairs. The apical rostral segment (RIV+V) is 1.2-1.7 times the length of the second hind tarsal segment (HTII). There are usually marginal tubercles on abdominal segments II-IV as well as on I & VII. The siphunculi are 0.8-2.1 times the length of the cauda. The body length of an adult aptera is 1.5-2.3 mm.

Adult apterae of Aphis verbasci are bright golden-yellow to pale-green and slightly wax-powdered (see first two pictures below). The apical rostral segment is very narrow, only slightly tapering and about 3.5-5.0 times as long as its basal width. Bands may occur on tergites 7-8, but may be absent. There is also a pair or irregular dark pleural sclerites on tergite 5 in front of the siphuncular bases - these are just visible in the two adult apterae in picture below, but are clearer in older adults. The black siphunculi are rather heavily built, strongly tapering and usually with a distinct outward curvature at the extreme base. The cauda of Aphis verbasci is short and tapering.

Second image copyright Dr László Érsek, all rights reserved.

Adult apterae of Aphis vernoniae (see first picture below) are yellowish to green, with pale siphunculi, and a pale yellow cauda. The legs are pale, with dusky joints and tarsi. The antennae are about one third the body length, with the terminal process 1.5-1.9 times the base of antennal segment VI (cf. Aphis coreopsidis on Eutrochium and Aphis gossypii, Aphis spiraecola & Aphis aurantii on Vernonia, all of which have the terminal process 2 or more times as long as the base of antennal segment VI). The rostrum reaches to the hind coxae. The siphunculi are pale, cylindrical, twice the length of cauda, 6.5-11.2 times their width at midlength, constricted at base and cylindrical or slightly flared on distal half, and almost flangeless. Body length of adult Aphis vernoniae apterae is about 1.4-1.6 mm.

First two images above copyright Mike Hatfield, third image copyright Susan Hewitt;
both under a Creative Commons License.

Adult apterae of Aphis verticillatae are mottled yellow-green (cf. Aphis salviae, which is shining brown). The siphunculi are dark, and the cauda is pale or dusky. The antennae are about 0.54 times body length, with the terminal process 1.7 times the base of antennal segment VI. The apical rostral segment (RIV+V) is less than 1.5 times (usually around 1.2 times) the second hind tarsal segment (HTII) (cf. Aphis passeriniana, which has RIV+V 1.54-2.02 times HTII.). The siphunculi are long, almost cylindrical on the distal half, with coarse imbrication; they are 6.8-9.0 times longer than their midlength diameter, and about 1.2 times the caudal length. The cauda has 4 hairs. Body length of Aphis verticillatae is 1.5-1.8 mm

Note: identification of images uncertain.

First image above copyright Gennadiy Okatov, second image copyright Savvas Zafeiriou
both under a Creative Commons Attribution 3.0 License.

Apterae of Aphis viburni are slate-coloured, brownish green or dark brown, sometimes with paired pleural wax spots on the abdomen. The sclerotic dark banding of the dorsum (just visible in the first picture below) is variable, confined to abdominal tergites 6-8 in smaller apterae, but with broken bands often present on some anterior tergites in larger specimens. Marginal tubercles are conspicuous (the brown lumps in the foreground of the second picture below) and subconical, very constant on tergites 1-4 but only irregularly on 5-6 (cf. Aphis fabae which does not generally have tubercles on each of tergites 1-4). Hairs on the femur and tibia are very long and fine and much longer than the least width of the tibia. The body length of Aphis viburni apterae is 1.83-3.04 mm.

Adult apterae of Aphis viburniphila (see first picture below) are reddish brown mottled with paler shades and marked with darker areas around and behind their siphunculi. They are not dusted with wax (cf. Aphis crassicauda & Ceruraphis viburnicola, which are both wax-dusted). The siphunculi are black and the cauda is dusky. Their antennae and tibiae are whitish to yellow with darkened apices. The femora are mainly brown, but pale basally. Antennal segment III often bears up to 15 small rhinaria, not in a row (cf. Aphis crassicauda, which has no rhinaria on segment III, except in obvious alatiforms). There are rarely any marginal tubercles on abdominal tergites II-IV (cf. Aphis viburni, which always has at least 6 marginal tubercles on those tergites). The tibiae bear long, erect hairs nearly twice as long as the diameter of the tibiae. The cauda is parallel-sided to blunt-tapering, with its length 0.9-1.3 times its basal width (cf. Aphis crassicauda, which has a cauda with length 0.5-0.9 times is basal width). The body length of adult apterae is 1.7-2 mm. Immature Aphis viburniphila (see second picture below) are reddish brown, with distinct darkened areas around the siphuncular bases.

First two images above by permission, copyright Claude Pilon, all rights reserved.
Third image above copyright Beatriz Moisset, via BugGuide, under a Creative Commons license.

Adult apterae of Aphis violae are dark green, mottled to a greater or lesser extent with pale green. The terminal process of the antenna is 2.4-3.7 times the length of the base of the sixth antennal segment. The abdominal sclerotic pattern is variable, with the most heavily marked having dark intersegmental muscle sclerites, small marginal and postsiphuncular sclerites and bars across tergites 7 and 8. Marginal tubercles are rather large, especially in alates.The siphunculi are black and 1.63-2.00 times the length of the dusky cauda. The body length of Aphis violae adult aptera is 1.1-2.0 mm.

The dorsum of adult Aphis vitalbae apterae has no wax (cf. Aphis clematidis, which is covered with powdery wax). The colour of the dorsum varies from very dark green (see first picture below) to mottled dark and pale green to pale green or yellowish (see second picture below). The antennae are pale, except for segment VI which has both the base and the terminal process darkened (cf. Myzus varians which has conspicuously banded antennae). The antennal terminal process is 1.7-3.5 times the length of the base of antennal segment VI. The apical rostral segment is 1.1-1.7 times longer than the second segment of the hind tarsus (cf. Aphis clematidis which has the apical rostral segment 0.75-1.0 times longer than the second segment of the hind tarsus). The siphunculi are either completely pale or dusky/dark at the apices (but see below for more discussion on this), and are 1.3-2.1 times as long as the cauda. The cauda is pale or dusky and is 0.17-0.21 mm long. The body length of the adult Aphis vitalbae aptera is 1.2-1.9 mm. Immature Aphis vitalbae show the same range of colour variation, but may show some light wax dusting.

In spring and early summer adult apterae of Aphis viticis (see first picture below) are mottled dark & pale grass-green with brown siphunculi. In midsummer dwarf forms predominate, which are pale straw-coloured with pale siphunculi. The longest hairs on antennal segment III are 0.4-0.75 times the basal diameter of that segment. The apical rostral segment is 1.05-1.30 times the second hind tarsal segment (HTII), and tapers almost to a point (cf. the polyphagous aphid species Aphis fabae, Aphis gossypii, Aphis nasturtii, Myzus ornatus & Myzus persicae, which all have RIV+V with blunt or rounded apex). The hairs on the hind tibiae are all shorter than the width of the tibia at midlength. Abdominal tergites I & VII have marginal tubercles. The siphunculi are tapering, pale or dark, or darker towards apices, and are 0.8-1.7 times the caudal length. The cauda is pale with 6-13 hairs. The body length of adult Aphis viticis apterae is 0.8-1.7 mm.

Both images above copyright Savvas Zafeiriou under a Creative Commons licence.