Pine silkworm is a voracious caterpillar that can cause irreparable damage not only in the garden, but also in large forestry. This insect gives particular preference to pine trees, but can be enjoyed by cedar and other representatives of the coniferous genus. Today, there are several really effective methods that can overcome the pest and save the trees.
Appearance
The silkworm or cocoonworm is a large-sized butterfly and caterpillar. Is a representative of the order Lepidoptera from the cocoonid family.
The color of the insect is variable, from gray, brown to brown. In general, the colors of the butterfly resemble pine bark as much as possible. On the upper wings of all individuals there are brown-red stripes, with a serrated black border. And closer to the head there is a white spot on each wing. The body with the lower wings is solid.
Males are slightly smaller than females, their wingspan is 7 centimeters, females 9. Another difference - females have a whisker, and males are comb.
The difference between a pine scoop and a Siberian silkworm
These two types of insects have many characteristic features, and, most importantly, both species eat pine. However, the pine scoop prefers young growth and is a nocturnal inhabitant. The color of the scoop is also different: their wings are brownish-green, reddish, that is, most suitable for the color of young buds of buds. At the caterpillar stage, the color of the insect is green, with white stripes, of which there are five and one white strip above the legs. Years of butterflies begin in the same period as that of the Siberian silkworm.
Distribution geography
Silkworm pine is present wherever pine trees grow. In Russia, a huge accumulation of insects can be observed along the shores of the North Donets, in the tape forests of Western Siberia. In the 50-60 years of the last century there were even protracted outbreaks of mass reproduction of the pest. The death of a pine from an insect is periodically observed in the Bryansk and Gomel regions.
Coconut moth prefers middle-aged plants. In places where it is very humid, it often dies from fungal diseases, therefore it prefers dry forests.
Breeding
The butterfly years fall in mid-June and ends around mid-August. Already in the middle of the first month of summer, females begin to lay eggs. They can be found on the bark of pines, branches, needles. One female is able to lay about 300 eggs, in one heap about 50 pieces.
Egg development lasts from 14 to 25 days and already in early August, young caterpillars appear, which, having matured, reach 8 centimeters in length. A distinctive feature of the cocoonworm at this stage is a reddish tint on the hairline and dark blue stripes on the second and third body segments. Thanks to this, perhaps, everyone recognizes in the photo a pine silkworm, as well as seeing it firsthand.
Nutrition and Development
Already on the second day from birth, the caterpillar begins to actively eat needles. By mid-autumn, insects descend to the ground and hide under the fallen branches and needles. Some individuals even burrow into the ground, about 10 centimeters.
Already with the first spring warming, the caterpillars climb onto the pines and begin to devour them actively, preferring young shoots. However, the insect is usually found on older trees, from 10 years old. Only by mid-June does the insect turn into a chrysalis. During this period of time, a huge number of pupae can be observed on the branches. And after about three weeks, butterflies begin to appear.
Most pine silkworm caterpillars winter for one season. But some individuals do not have time to fully develop and winter for two seasons.
Harm
Cocoonworm, like most insects, along with harm, has certain benefits. First of all, the insect eats the old needles of diseased trees, and only with a huge population it moves to young growth.
One adult is able to eat 60 needles per day, if you count for the entire period before pupation, you get more than 1 thousand pieces. Naturally, the trees simply do not have time to recover if the region has a huge population of cocoonworms. During a drought period, insects are able to absorb hectares of forests, because it is drought that is the most favorable factor for reproduction and growth.
An interesting fact is that in the same region, massive outbreaks of population growth can be observed for 5 consecutive years.
Danger to humans
Butterflies do not carry any danger to humans, but the situation with caterpillars is different.
The usual pine and marching silkworm at the caterpillar stage has a hairline on which there are toxic substances. The poison is contained in minimal doses and is designed to protect the caterpillar from insects and birds. However, he can also cause trouble to a person. Naturally, it is impossible to poison the poison from the hairs of the caterpillar, but it strongly irritates the mucous membranes and the skin. Therefore, it is strongly discouraged to take the cocoon moth in hands at the caterpillar stage.
Natural enemies
The main enemy of the cocoonweaver is the egg-eater. The larvae of this parasite develop in silkworm eggs. Butterflies themselves transfer this parasite on their body to masonry places. The egg-eater himself, being an adult, barely reaches 1.7 mm in size.
Silkworm eggs feed on rider flies and tahini. Hedgehogs and shrews eat eggs. Muscardins are fungi that kill silkworms.
Methods of struggle
If a small population of pine silkworm is found, then this place is isolated from the rest of the trees, grooves burst, thereby preventing pests from moving to healthy trees. Affected and isolated trees are treated with caterpillar glue. If there was a massive infection in large areas, then they carry out sanitization with dust with the help of aircraft.
Good results are toxic belts. The procedure is carried out at the end of March before the caterpillars begin to wake up before wintering. The essence of the treatment is that the trunk of the plant is treated with dust at a height of about 1.2-1.5 meters from the ground.
Additional biological methods of controlling cocoonweeds include the additional resettlement of natural enemies. Good results can be achieved with the telomes ovipositor. At the same time, the telenomus spreads quickly enough, if several individuals of the pest are placed on one clutch, then in just a couple of days the pest will spread to 300 meters.
In some cases, formic ants are resettled, which are also a natural enemy of the silkworm. The ant is under protection, therefore, its artificial resettlement is justified.
In household plots, you can process pine with dust, or use special tools, for example, "Karbofos".