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Earwigs.
Adult insects. Predatory, phytophagous, saprophagous, consuming stored produce, and mycophagous. Small to medium sized; with hardened ‘elytra’ (q.v.), representing the fore-wings; capable of flight; with one pair of propellant wings (the hindwings). Body dorsiventrally flattened. Head prognathous. Mouthparts well developed; of the biting type; not piercing; more or less conforming to the generalized biting type (the mandibles usually with two apical teeth, and parts of the maxillae much divided). Antennae conspicuous; simple; 15–35 segmented (‘many-segmented’). Ocelli 0. Wings four; markedly differently textured in the two pairs. Fore-wings leathery (comprising short elytra). Hind-wings larger than the fore-wings (when opened); much markedly broader than the fore-wings; folded in repose (folding under the small elytra). Wings with few cross-veins; more or less naked. Wings of the resting insect closed and directed backwards. Tarsi 3 segmented. Abdomen conspicuously appendaged at the rear; furnished with very large, paired, pincer-like appendages; with cerci clearly visible at its tip (represented by the much enlarged, characteristic ‘pincers’, which are sometimes used to capture prey); apparently 10 segmented (males), or 8 segmented (females, where terga and sterna of 8 and 9 are reduced, and fused to tergum 10).
Larvae. Larvae with three pairs of segmented thoracic legs; without ventral abdominal prolegs. Development of larva into adult gradual; exopterygote; not involving a pupal stage.
Classification. Subclass Pterygota; Division Exopterygota.
British representation. Anisolabidae, Forficulidae, Labiduridae, Labiidae; genera 7 (Anisolabis (casually introduced), Apterigida, Euborellia, Forficula, Labia, Labidura, Marava); 8 species.
General comments. The hind-wings are characteristically rounded, with with radiate venation. The eggs are deposited in the soil in a group, and the female sits over them and guards them and the newly hatched young until they can look after themselves, gathering them together again if they become separated.
Illustrations. • Apterygia, Euborellia, Forficula, Morava (Lucas). 1–3, Euborellia annulipes (Ring-legged Earwig): 1 and 2, female and antenna; 3, callipers of male. 4, Marava arachidis (Bone-house Earwig), adult male. 5 and 6, Forficula lesnei (Lesne's Earwig), adult male and callipers of female. 7, Apterygia media (Short-winged or Hop-garden Earwig), adult male. From Lucas (1920), with 1cm scale for the complete insects. • The British Earwigs (Burr). LABIDUROIDEA-Labiduridae. 1 and 1a, Labidura riparia, male and forceps of female (extinct?); 2 and 2a, Anisolabis maritima (male and forceps of female: introduced, occasionally persisting); 3, Anisolabis annulipes (female). FORFICULOIDEA-Labiidae. 4, Labia minor, male; 8 and 8a, Marava arachidis, male, and forceps of female. FORFICULOIDEA-Forficulidae. 5, Forficula auricularia (male), with forceps of a small male (5a), forceps of female (5b), and wing expanded (5c); 6, Forficula lesnei (male); 7, Apterygida albipennis, male and (7a) forceps of female. S.L. Mosely's plate, from Burr (1897: scales include pincers). • Forficula auricularia, as F. borealis (Northern Earwig). B. Ent 560. • F. auricularia, as F. borealis (detail). B. Ent 560. • <@subject Forficula auricularia, as F. borealis (detail). B. Ent 560> : B. Ent 560). • Forficula auricularia, and forceps of other Forficulidae: Stephens VI, 1835. The Stephens portrayal of Forficula forcipata (4, = F. auricularia) is accompanied by confusing representations of the forceps of assorted Forficulidae, labelled on the plate as follows (modern nomenclature in parentheses). 1, Forficula auricularia; 2, Forficula media (= Apterygidia albipennis); 3, Forficula borealis (= F. auricularia?); 5, Chelidura albipennis (= Apterygidia albipennis?). From Stephens vol. XI, 1835. • Labidura riparia (Lucas). Labidura riparia (Giant or Tawny Earwig), male (1) and female. From Lucas (1920), with the approximate insect lengths including callipers. • Earwig, adult (left) and larva (Lubbock 1890).
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. Insects of Britain and Ireland: orders. Version: 14th April 2022. delta-intkey.com’.
