The main pest of forests and gardens is unpaired silkworm

Dangerous pest of forests and cultural plantations unpaired silkworm is characterized by a wide distribution area. This pest can be found in Asia, Europe, North Africa, in the northern part of America. It covers the entire territory of Russia, is found in the south, in Siberia and the Far East. Deciduous tree species are especially affected by caterpillars. In the absence of food, silkworms move to young conifers. Once in the nursery, insects are capable of causing significant damage to the plantations.

What does an unpaired silkworm butterfly look like?

An unpaired silkworm is a butterfly belonging to the order of Lepidoptera from the family of Piper. A distinctive feature of these insects is the noticeable differences between males and females.

Differences in adults are noticeable in color and shape:

1. Females - the size of the wings when unfolded reaches 90 mm. The thick body has the shape of a cylinder. A grayish fluff is visible on the abdomen. The antennae are thin and long.
2. Male - wingspan 40-50 mm, thin body, covered with hairs. The color of the wings is brown, the surface is covered with a pattern of dark spots and broken lines. The antennae are comb.

Moth silkworm butterflies prefer light woods, dry places with plenty of light. The first foci of distribution are usually at the edges. During droughts, large outbreaks of mass reproduction of silkworms occur. This species leads among pests in the number of outbreaks of breeding and the duration of these periods.

Silkworm breeding

Heavy females rarely fly, they sit on the bark of trees and attract males with the help of pheromones. Males begin years several days earlier. They are especially active in the evening. In search of a pair, they fly long distances. After fertilization, the females lay their eggs under the bark of trees at a height of 3-4 m. They are round in shape, yellow or pinkish in color. Size - 1 mm, the number of eggs in the masonry of unpaired silkworm - 100-1000 pieces. In the state of the egg, the insect spends most of its life - about 8 months.

An embryo forms inside the egg shell, which remains to hibernate. In spring, with a rise in temperature to +10⁰ the first caterpillars appear. For a while they sit motionless, then creep on a tree. The body of small caterpillars is covered with bristles and air bubbles. This allows them to travel with gusts of wind. To travel long distances, insects can release cobwebs.

Interesting fact. The caterpillar is the only form of garnet that feeds, storing energy for the remaining phases of development.

Unpaired silkworm belongs to the family of cocoonworms. The caterpillar appears with sixteen legs. At birth, it is light yellow, but quickly darker and becomes brown or black. On the body are several longitudinal rows of warts.

Information. Unmatched silkworm eggs are extremely resilient, they are able to withstand frosts down to -50.

After moving to a new territory, active food begins.Young caterpillars eat in the daytime, gnawing small holes in the leaves. After 3-4 months, they switch to food at night, eating the leaf completely. In addition to foliage in the diet of pests, buds, young shoots, flowers. Depending on the climatic zone, caterpillars need 50 to 80 days to develop. Then they pupate. This occurs in June-July, the pupal stage lasts 10-15 days.

Information. The optimum temperature for insect growth is + 20-25, if it drops to +10, development stops. Male caterpillars up to the adult stage (adult) survive 5 stages of the larva, females - 6 stages.

Spread and harm

The pest has a wide distribution range. In Europe, it occurs before Scandinavia, in Asia it covers many countries: Israel, Turkey, Afghanistan, Japan, China, Korea. An interesting story is the butterfly entering North America. The insect was introduced artificially for carrying out experiments on crossing with other species. Larvae managed to spread from the territory of the experiments into open forests. The problem that has arisen was not given due importance and over the course of several years, unpaired companions seized a vast territory. Only in 1889, unpaired silkworms were recognized as a pest. But the insect is already firmly entrenched in the new territory.

Interesting fact. Due to the wide distribution range, butterflies are divided into races. In Russia, there are Far Eastern, European, Siberian and other races.

The caterpillar of an unpaired silkworm exposes deciduous trees in forests and gardens. She prefers fruit plantings of apple trees, plums, apricots. In the wild, he chooses oak, birch, linden. Bypasses ash and alder. In total, the pest eats about 300 species of plants, not excluding conifers. The main division occurs in the European and Asian races. The Asian group is a real polyphage, feeds on various types of trees and bushes.

Varieties of unpaired silkworms

Butterflies of unpaired silkworms are assigned to different species depending on the places of residence and feeding habits. Among the common groups:

Ringed silkworm

This is a small representative of its kind. The size of the wings of females is 40 mm, males are 30 mm. The insect is common in Europe and Asia. The caterpillar will grow to 55 mm; it is gray-blue in color with white and yellow stripes. Pests live in colonies, create spider webs. In the fight against unpaired silkworms, it is necessary to cut and burn branches where the ovipositor is seen. The trees themselves are sprayed with insecticides.

Marching silkworm

Silkworms are characterized by the ability of caterpillars to migrate to new feeding sites. At the same time, they line up in a long chain, following each other. The first caterpillar, which is the leader, releases a silk thread along which the remaining insects are oriented. There are two types of marching silkworms - oak and pine.

Coconut Moth

Insects are common in coniferous forests of Siberia and Europe. They damage pine plantations, less often than other species. Grayish-brown females are 85 mm in size, males - 60 mm, caterpillars - up to 80 mm. Caterpillars spend the winter in the ground under tree trunks. In the spring they rise for feeding, pupate in July.

Siberian silkworm

Unpaired Siberian silkworm feeds on conifers. This species damages spruce, pine, cedar and fir. The insect settled in the forest and forest-steppe zone of Siberia. The northern border of its distribution passes through the Arctic Circle. The development of silkworm from egg to butterfly in a cold region takes 2 years. In warmer years, it can accelerate to a one-year cycle. Butterflies of the Siberian silkworm are distinguished by a variety of colors. There are brown, gray, and black adults. The wingspan of females is 6-10 cm, males are more modest in size - 4-7 cm. Three dark jagged stripes run across the front wings. Hind wings are brown. The head and chest are the same color as the front wings.

The laying of butterflies is bluish in color, the size of the eggs is 2 mm. They are laid off in uneven heaps of 100 pieces. Placed in the bark, needles and twigs. When it appears, the larva eats up half of the shell. Caterpillars grow up to 11 cm, their bodies are gray or black. On the back are blue hairs. Insects are able to take a threatening pose. At the same time, they raise the front of the body and bend their heads. A strip of bright yellow color runs along the sides. The body is covered with hairs, in front and on the sides they are the longest.

The head of the caterpillar is brown, orange spots are located on the abdomen. The pupa of the Siberian silkworm is dark, almost black. Its length is up to 5 cm, the cocoon is suspended on branches or between needles. Burning hairs are woven into its shell. The local silkworms distinguish three races:

• larch;
• fir;
• cedar.

Silkworm caterpillars calmly tolerate cold, they leave for wintering at a temperature close to 0⁰. They creep into the trees after wintering immediately after the snow melts. As it grows, resistance to frost increases.

Information. When frozen to -10 caterpillars die, they do not survive the snowy winters.

Pest Control Methods

The identification of a partner occurs on gnawed leaves, excrement, butterflies and oviposites in the web. Basic information is taught by studying the imago and the number of eggs in the clutch. This provides information for prediction, allows you to determine the phase of the flash. Pest control methods are selected depending on the degree of their distribution.

Attention. The Siberian and Far Eastern races of silkworms represent a quarantine hazard. A thorough inspection of goods and vehicles coming from the Siberian region is carried out. Pests are lured using pheromone traps.

How to deal with unpaired silkworms in your garden? You should carefully monitor the trees. When signs of caterpillar damage appear, begin the destruction of the ovipositor. They are visible among foliage, cut nests and burn along with eggs. Caterpillars can be assembled by hand, this tedious procedure is feasible in small areas. An effective way - the device of adhesive rings, crawling caterpillars will stick to the surface of the traps. In autumn, egg laying is scraped from the bark of trees.

Attention. Wear protective gloves when working on pests.

The use of insecticides is the most effective measure to control unpaired silkworms in the garden and forest. In early spring, trees are treated with "Chlorophos", "Metaphos", as well as organophosphorus compounds.