Birch moth - how to deal with the invasion of caterpillars

The family of moths has about 23 thousand species. Most of them are dangerous pests of forests, fruit and ornamental crops. The most famous species, which is often described in biology, is the birch moth. Its habitat covers all of Europe, Central Asia, southern Siberia, the Caucasus, Sakhalin, Korea and Japan.

Insect appearance

The birch moth belongs to the order Lepidoptera along with other butterflies, moths and moths. The length of the wings is 22-25 mm, wingspan - 43-50 mm. The insect has a thick cone-shaped body. On the front and hind wings is a cover of chitinous scales. The body of the insect is divided into three main departments: head, chest and abdomen. Long antennae are sensory organs; they perceive vibrations and smells. Butterflies are active mainly at night.

Biston betularia or birch moth is light in color. Her wings are covered with a pattern of black dots and longitudinal stripes. At moths Sexual differences are clearly visible. Males have developed wings, in females they are reduced, and in some cases are absent. Butterfly refers to a species with a full development cycle. She goes through all stages:

• egg;
• larva (this species has a caterpillar);
• pupa;
• adult (adult).

Interesting fact. Insects got their name due to the behavior of caterpillars. They move, folding and straightening the body, as if measuring the length of a span - the distance from the extended index to the thumb. The Latin name Geometridae means "surveyor", which is associated with the same feature.

Breeding

The years of birch moths begin in May or June. Adults fly out of the cocoon and mate. The female lays a large number of eggs under the bark of trees - 600-100 pieces. They are oval in shape, by the time the larvae appear brown. The peculiarity of the caterpillars of this species is the differences in color. There are individuals of green color with a red stripe on the back. Other specimens are brown with a black mark. Their length is 40-50 mm. On the caterpillars, white warts are located on the 8th and 11th segments of the abdomen.

Pest larvae have a special limb structure. Their legs are located on segments 6 and 10 of the body, so when moving insects pull the back of the body to the front. The color of the tracks is camouflage. They feed intensively, become food for larvae in the forest: oak, birch, linden, acacia. When pests get into the garden, they eat leaves of fruit trees - apple trees, plums, cherries, and also currant bushes. The full life cycle of an insect takes a year. In autumn, the caterpillar pupates in the soil. She hibernates in a dense brilliant cocoon of brown color.

Information. The caterpillars have very developed musculature, they can catch on their cortex with their hind limbs, rise, and freeze motionless for a long time. In this position, they look like a thin twig.

Case Study of Evolution

Butterfly birch moth is known for its ability to change color. This property was manifested under the influence of external factors caused by human activity. The process of natural selection, which caused the appearance of a dark color, was called industrial melanism. Until the middle of the XIX century, insects had white wings with black spots.This range provided them with a good disguise against the background of bark of birches. Butterflies hid among lichens and were invisible to enemies. Later, monochromatic colonies of birch moths appeared near large industrial centers in Europe and North America ... These insects changed their primary color to black, a new group appeared - Biston betularia carbonaria.

Such changes, melanistic forms, arose as a result of natural selection. In areas with developed industrialization, lichens disappeared, and trees became covered with soot. Bright moths were quickly eaten by birds, so the protective color changed to black. Dark butterflies easily camouflaged against the background of dirty trunks. In clean areas, the color of butterflies remains light. An intermediate form has appeared, living on the border of industrial regions, its color is gray with a black pattern.

Information. After the adoption of laws aimed at preserving the ecology, the black-painted group lost its advantage. The amount of Biston betularia carbonaria has decreased significantly.

Pest Management Methods

Insects bring damage to plants at the caterpillar stage. Voracious larvae eat buds, flowers, leaves, fruit ovary. Gathering in large numbers, they cause significant damage to the garden or forest area. Pesticides are used on an industrial scale to control pests.

Mechanical methods

If destruction is carried out on a personal site, then mechanical methods are also used. Butterfly females fly poorly, so they climb a tree along the trunk. Glue belts are arranged against them. Their basis is thick paper, plastic film or rubber. Non-drying glue is applied to the surface.

A sticky trap can be purchased at the store. On sale there are hunting belts of various manufacturers: "Argus", "Mashenka", "Trap". They are 5 m long tapes that are coated with waterproof glue. The composition does not dry out within 60-90 days. A trap is an environmentally friendly and effective way to protect trees from pests. Not only butterflies remain on it, but also aphids, bugs, ants, ticks. The belt is installed at a height of 7-100 cm from the ground. It is removed in the fall and burned. Mechanical caterpillar picking is possible, but this is a complex and time-consuming procedure.

Tip. On apple trees, the trap is left until November. It prevents one of the species of butterflies from falling onto a tree - winter moth. The pest lays eggs under the bark in late autumn.

Do not forget the annual agricultural activities that contribute to the destruction of pests:

• collecting fallen leaves and dry grass under the trees;
• digging of soil in near-stem circles, allowing to destroy larvae and pupae;
• timely removal of growths and moss from the bark of fruit trees;
• whitewash trunks.

Information. Moths are characterized by outbreaks of mass breeding associated with special climatic conditions. Such a period can last several years. During this time, caterpillars destroy trees in a large area. The largest outbreak was observed in 1940-44. It covered the whole of Europe, including the western part of Russia.

Chemicals against moths

Trees should be sprayed with biological pesticides, organophosphates and other insecticides. Modern biological products effectively destroy pests by contact-intestinal action. Organophosphorus compounds have a nerve agent effect on insects. Systemic drugs are used that enter the body of the caterpillars through breathing, nutrition, or direct contact. Among the recommended formulations are Karbofos, Neoxin, and Decis.

The fight against birch moths will be effective if all of the above methods are used.