Unpaired silkworm - one of the most dangerous pests

Unpaired silkworm (photo can be seen below) is one of the most famous pests, which causes considerable damage to deciduous and coniferous trees. Its name was received for a too big difference between a female and a male. If the female has a massive thick belly, and the wingspan reaches 75 mm, the male is characterized by a thin belly, and its wingspan is only 45 mm. Unpaired silkworm-male has brown-gray wings with dark, discontinuous strips. The female has dirty-white wings with zigzag black lines.

Unpaired silkworm-caterpillar colored yellowish color with a marble dark pattern. On the cylindrical body is a fairly large head with brown strips. The newly released young caterpillars are black and covered with hairs. Adult individuals reach a length of 40 to 80 cm. Unpaired silkworm pupa-mummy, dark brown, up to 30 mm long.

In warm regions butterflies appear from late July to August, in colder regions - a month later. The males are the first to begin their life. Females begin to fly a few days later, although they are heavy and prefer not to fly, but sit on the bark of a tree. Males fly fast, especially in the evening, in search of females, who are attracted by pheromones. Fertilized females lay eggs on the bark of deciduous trees . One unpaired silkworm leaves between 250 and 500 eggs. The butterflies themselves will live no more than two weeks, but the eggs will overwinter, and when the temperature rises to +10 ºC (usually this happens in April), small caterpillars will appear.

The first few days they live together and do not feed. But then they spread all over the crown and in young leaves gnaw small holes, and they feed mainly in the daytime. The older individuals eat foliage in a manner characteristic of them, and very often the remains of the leaves lie on the ground. The time of intensive nutrition they have at night, although with outbreaks of mass reproduction, they can eat foliage and day. If there are not enough food for the caterpillars, then they proceed to the tissues of immature shoots, kidneys or flowers. After intense nutrition, the pupation begins. This occurs in the first half of July, but in the southern regions - at the end of June. For about 15 days, the pupa stage continues.

Unpaired silkworm - this is a pretty many-malicious pest. More than 300 plant species can damage its caterpillars. They damage almost all deciduous species and do not pass by such representatives of conifers as fir, pine or larch. Very like shrubs and fruit trees, cultivated cereals, strawberries, sedge, cranberries and cranberries. Especially viable and prolific is the offspring of an unpaired silkworm, if the caterpillars feed on the leaves of poplar, oak and fruit trees.

In Russia, unpaired silkworms are distributed practically throughout the European part. It also occurs in the Far East and Altai, the Urals and the Caucasus, Siberia, Central Asia and Northern Kazakhstan. In the XIX century, he was brought from Europe to the state of Massachusetts (the territory of the USA) and by 1952 spread throughout the country, having acquired there also the status of one of the most dangerous pests.