POPLAR
AND WILLOW PESTS
1.1. Melanophila picta Pall.
This
insects is very important pest. The adults emerges between the end of may and
august. They deposit their eggs in the fissures of the bark of lower parts of
the trunk (first 2-2,5 m, especialy base of trunk). After the incubation period
of 10 days the larva penetrates into the trunk immediately where they feed on
the bark and sapwood layers; then they constructs tunnel galleries in the wood
where they overwinter (Figure 1-2). In the spring, after being pupa which last
15-20 days, adults appear. This insect has one generation per year. Attack on
the lower part of the trunk weaken the tree which is then liable to be snapped
by wind. In order to protect the poplar plantations against this insect regular
irrigation and the culturel methods should be done very strictly.
1.2. Agrilus ater L.
The
adults emerge from june to july and deposite their egg packages on the trunks.
On the attacked trunks some spots and liquid flows are observed and when the
bark is pushed it caves in interior section. Its larvae emerge ten days later
and form some sinusoidal channels in the cambium region (Figure). At the
beginning of winter larva penetrates into the wood 3-4 cm and hibernates.
Pupation take place in the middle of Spring and adults emerge on june-july. It
is known as a secondary pest therefore modern cultural technique method
applications are necessary in establishing new poplar plantation free from
attack. The attack of Agrilus ater
L. are observed in the plantations
on salty, heavy and bad drained soils.
1.3. Sciapteron tabaniformis Rott.
This insect generally attacks sapling and young poplar plantations (1-5 years old). Generally, it lays its eggs at 1.5-2 m above the ground . The adult insects resemble wasps (Figure). Betwen May and August, the fameles lay eggs seperate one from another; after an incubation of 10-15 days, the larvae hatch and penetrate the tissues below the bark; the plant reacts by forming a swollen nodule. Later they penetrate the wood as far as the pith where they bore a tunnel 10-15-cm long at the end of which they prepare a pupation chamber. The insects overwinter in the larval form. After 20 days pupation period, the adults emerge by the entrance hole to the gallery or by another opening which larva contrives for this purpose. In preventive protection against the attack of this pest, internal quarantine is introduced when taking plant material out of a nursery; other meassures consist in avoiding pruning in flying period and mechanichal lesions of trees in poplar plantations in the course of soil tillage. For chemical control, is observed to emerge of adult, Starting twentieth day after the appearance of the first adult is exercised through two or three treatments.
1.4.
Cryptorhynchus lapathi L.
This serious pest’s adults emerge from June to August and begin to mate almost immediately. The eggs are inserted into the bark usualy near the cork areas at the peduncle scars. Larvae hatch, after 15-20 days egg laying. Each female lay down an average 20-30 eggs. New- born larvae overwinter cortical and subcortical layers in the stem (Figure ). In the spring time they begin to bore a tunnel, which usualy surreands all the stem, and finally penetrate the wood . Pupation takes place in a small chamber placed at the end of the tunnel and lasts 15 days. Insect damages (Figure )are very heavy because the trees often are broken off by the wind, near the larval ring tunnel of present some overswelling.
1.5. Gypsonoma (=Semasia) aceriana Froel.
The insects attack terminal or lateral buds (Figure). The adult appears at the end of the May and the females deposit their eggs on the upper side of the leaves. On emerging, the larva move toward the underside of leaves, penetrate into the parenchyma near a vein and then tunnels a small gallery. 15 days later, it moves toward the leaf bud and there bores a gallery of 3-5 cm. After a mounth feeding, mature larva pupates in the ground in a cocoon of silk threads. Adults emerge in August to give a second generation. At this stages eggs are again deposited on the leaves, but the larva remain there until leaves begin to turn yellow. Then they move toward the branches and stem, bore a small hollow in a bud which they then cover with silk tissues mixed with waste, and there pass the winter. In the following spring the larvae move to the terminal, or lateral buds which are still partially closed, penetrate and feed in the tissue of the shoot. Then they pupate in the ground. Chemical control must be done, when larvae feed on the leaves.
1.6. Chionaspis salicis L.,
Lepidosaphes ulmi L.
The most common coccoidae are Chionaspis salicis L., and Lepidosaphes ulmi L. These insects sometimes proliferate in such vast numbers as to completely cover trunks and branches with their scales. C.salicis have grey oval shape scale (Figure). The shape of L. ulmi looks like a comma and colour is grey . Chemical control are applied against these pests in winter and summer season. In winter the target stage of pest is eggs and adults under scales. Second control time is spring and the beginning of summer when crawler emerge and before forming scales.
2.1. Capnodis miliaris Klug.
The adults emerge between the end of May and August, and feed on leaves and young shoot, then overwinter in the soil or under the dried leaves (Figure). The end of May of following year, they begin to feed again and mate. It lays its eggs between beginning of June and the end of August in Turkey. It leaves its eggs on the earth into the fissure of the soil. The incubation period is 12-13 days. The death of the eggs increases with the augmentation of the humidity. Hatching larvae penetrate into the foot of poplar stems and into the larger roots, and feed between the bark and wood . They are generally below ground level. The larva stays inactive through the winter, feeding starts again in the following spring and pupates between May and June. The metomorphosis lasts 20 days. So, this insects passes one generation every two years. The insect likes high temperatures and prefers to attack the plants which are suffered from dryness. Preventive measures are, using the most suitable sites for planting poplars, irrigating regularly every ten days, during the period of egg-laying, so that the degree of soil moisture does not fall below 80 percent. The target for chemical control is newly hatching larvae which try to reach the plants for attacking.
2.2. Melolontha melolontha L.
The larvae of these insects live in the ground and damage the roots. The attacked saplings’ leaves at first turn yellow and finally the sapling dies. The adults begin to leave from the soil in the end of April- May and attack the leaves of poplar and willows. The female lays its eggs generally in three period, each group includes 10-30 eggs. An adult lays totaly 70 eggs during its whole life. Eggs are deposited 10-15 cm depth of the soil. The egg laying period lasts about 25 day. Larvae hatch in 4-5 weeks and emerged larvae attack thin roots. Larvae move deep layer of soil, when the weather begin to cold. Larvae move to upper surface and feed with roots in spring. In the second winter they go again deep layer and overwinter there. In the spring they move upper and are nourished with roots till beginning of the autumn (Figure). The Matured larvae move deep soil and pupate and after that become adult. They overwinter as adults. After passing 3 winters of egg laying, Adults appear in the end of April and May.
3.
Defoliating insects
3.1
Stilpnotia (Leucoma) salicis L.
The Adult emerges in the end of May and June. Female deposites its eggs in oval masses which have 150-200, covered with a white satiny secretion on trees. After 15 days, the larvae hatch and begin to feed on leaves (Figure ). Larvae become mature in July and pupate in cocoons attached to leaves with silkish ropes . Second generations adults emerge in August. This generation’s larvae feed in a short time, then spin cocoon in bark crevices where they pass the winter. They begin to feed again in spring and larvae reach maturity in May.
3.2.
Melosoma populi L.
The adults hibernate during the winter in debris beneath the trees and in other sheltered places, appearing early in the spring to resume feeding. Clusters of eggs are deposited under leaves. Each cluster have 20-60 eggs and larvae hatch in 7-15 days. Feeding period of larva lasts 20-25 days. They pupate under the leaves, the adults emerge one week later. They have three or more generation annualy. It is observed together egg, larva and adult stages on a tree (Figure ).
3.3. Lymantria dispar L.
The male moth is light to dark brown and has a wingspread of 35-45 mm. The forewing have a band of dark brown or black along the edge and irregular bads or lines of the same colour across the center of the wings. Female moth has a light brown, or buff-colored body and has wingspread of 55-65 mm. The forewins are white, with a pattern of light brown zigzag bands and a row of dark dots along the outer edge. Adult moth emerge July and females lay their egg masses on tree parts, and the eggs overwinter . In the spring eggs hatch about the time leaves unfolded. Larvae feed greedily and mature larvae pupate on the leaves and branches . After 10-15 days adult begin to emerge. There is one generation in a year.
3.4. Byctiscus populi L.
Adults hibernate in the ground and appear April and May. After feeding on leaves and buds for 10-15 days, females roll the leaves into a cigar shape and lay there average 4 eggs. These eggs hatch in 10 days and whitish larvae emerge. The larvae are nourished into fold to 20-25 days. The larvae falling with cigar, pupate in the ground. After 10 days pupation period, adults emerge and overwinter in the ground. When there are vast number of cigars in plantation, cigars are collected and destroyed (Figure). After the cigars fall to the ground, Soil is deeply ploughed.
3.5. Nycteola asiatica Krul.
Female moth lay milky white coloured eggs cluster on the young leaves of terminal shoots of poplar in the end of June and August. Larvae hatch in 2-3 days. Colours of new larvae are light yellow- cream, later yellowish, light green and finally green. The larvae feed on the parenchyma, being protected by a close-woven silky covering. If The wheather is cold, they prepare a cocoon on feeding leaves and overwinter in larva stage. If the weather is convenient, they pupate and adults emerge 15 days later. There are three generation, even if four generation in convenient cases.
