Dresser odorous (willow)

Borer odorous (Cossuscossus) is a pest of deciduous trees, among which willow predominates, which is why it received the second name - willow. Often damages the wood of fruit trees. The development takes place a full cycle - from egg to moth. The insect is hardly noticeable, since the adult woodworm is odorous, thanks to mimicry, merges with the bark, and the caterpillar rarely leaves the stroke made in the trunk.

Appearance at different stages of development

Insect refers to the order of Lepidoptera or butterfly.Adult individual is nocturnal. The front wings mimic the pattern of the bark of the tree, which allows the butterfly to remain invisible. Hind wings slightly darker, transversely striated. The insect chest has a characteristic pattern. The appearance of the mask gives it a graduated color - dark at the top, it brightens closer to the abdomen. The black horizontal bar divides the chest into two uneven parts.

A rare feature in moths is the lack of a mouth apparatus. The fragrant woodworm does not feed, but lives off the reserves that it accumulates in the caterpillar stage.

Like all moths, the willow tree flowers have well developed olfactory organs. Sensilla localized on the surface of the antennae.

The organs of hearing are located on the base of the abdomen or in the area of ​​the posterior thorax. Dresser odorous perceives the sounds of high frequency and ultrasound, which allows it to respond to the approach of bats.

Borer odorous

The abdomen of the butterfly is oblong, thick, with well-defined segments. On the outer edge of the segments visible thick gray pubescence. Scales in the form of hairs cover the whole body of imago, except for complex faceted eyes.

The size of the adult female is slightly larger than the male.The floor of the butterfly can be distinguished not only by its size, but also thanks to the well-visible egg-laying coming out of the abdomen.

A large, heavy butterfly flies low above the ground. In the evening and at night, she crawls along a tree trunk. By folding the front wings with a hut, the insect protects their abdomen, which makes it indistinguishable against the background of bark folds.

The caterpillar is large, bright. The color of chitinous cover changes with age. Juveniles are pink. Gradually, the caterpillar darkens, acquiring a reddish-brown or cherry color with a darker back. The body is covered with sparse hairs. The head is black, equipped with powerful mandibles - jaws, at the base of which are located glands that emit a secret with a strong smell of woody vinegar.

Pupa reddish-brown with a light yellowish belly.

Features of reproduction and development

The whole cycle of transformation of fragrant wood borer passes in two years. Adult adults begin to age depending on the air temperature. In central Europe, summer begins at the end of May and lasts until the beginning of August. In the warm south, the first butterflies appear in April, and in the cold north in late June. This period lasts about 14-16 days.

After fertilization, the female lays 300-1400 eggs, in groups of several dozen. The female takes care of the offspring only in the egg phase. She covers the top of the eggs quickly hardening in the air secret of the accessory glands. The egg phase lasts 1.5-2 weeks. Masonry is located in the butt of the trunk, in the folds and cracks of the bark.

Eggs and woodworms are odorous

The young caterpillars that emerged from them burrow into the bark, forming a broad common move above the bast. Growing up, the caterpillars damage the bast and cambium, gnawing interconnecting passages that are filled with fine wood dust and excrement. According to the brown discharge, it becomes clear how to find an odorous woodworm. After wintering for the first time, adult caterpillars go deep into the trunk, gnawing wide oval passages directed from the base of the trunk upward.

Important!

The caterpillar of a fragrant woodworker of the first wintering does not leave a tree. It can be seen only when cutting down a tree or it will detect the external openings of the passages. If you smell it, the presence of a caterpillar gives off a pungent smell. Adults occasionally can be seen on the ground when large, up to 8-12 cm caterpillars crawling in search of a place for pupation.

The fragrant woodworm in the photo is depicted below in the stage of a caterpillar and butterfly.

In the period from May to June, the caterpillars pupate, forming around themselves a dense cocoon of sawdust, in the same place where they wintered, or crawling into the soil. Silk threads form the basis of a cocoon into which willow borers interweave tiny lumps of soil or drilling flour. The pupa develops within 2-6 weeks. After that, the pupa is half a length protruding from the cocoon.

Thus, fragrant wood borer passes two stages in two years:

• Egg - 12-16 days;
• The larva is a caterpillar;
• Dolly - 2-6 weeks;
• Imago or butterfly - 2 weeks.

The fragrant tree borer causes the greatest harm to green plantings at the larva stage.

Pest control methods

Trees, chosen by tree borers, are ill, and can be killed during mass settlement. This rarely happens, but in order to prevent damage to fruit trees, the stumps are whitened with a special emulsion that protects the bark from cracking and embedding the larvae. The outer openings of the passages are filled with cotton balls soaked in an insecticide, or liquid is injected into the cavity. Top hole smear garden pitch, a mixture of clay and hydrated lime.

They carry out mechanical cleaning of trunks from fallen bark and caterpillars. Damaged branches are cut.If the tree is badly damaged, then it is removed, and the collected caterpillars burned.

Interesting!

Despite the wide area of ​​distribution, in some countries the fragrant wood borer is listed in the Red Book. Fishermen are happy to collect caterpillars, as they are excellent catfish. They are not easy to find and can not be collected with bare hands, but even from a damaged larva you can make an attractant for fishing.

Some insect lovers grow woodworms at home due to large and bright caterpillars. Despite the fact that willow borer is a pest, it is interesting to study it as one of the largest species of moths.