Pest Type: Fruit Pests
Row: Lepidoptera – Lepidoptera
Family: Moths – Geometridae
Mass breeding zones – Polesie, Forest-steppe. It damages all fruit, as well as oak, elm, maple, birch, willow, hornbeam, ash, bird cherry.
Butterfly with pronounced sexual dimorphism. A male with a wingspan of 20-25 mm; fore wings are brownish-gray with dark wavy transverse lines; hind wings lighter, plain; the female is brown-gray, with long legs and antennae, with short outgrowths 2-3 mm long, which reach the first segments of the abdomen; abdomen inflated, in small black dots, body length – 8-10 mm. The oval egg, 0.8 mm in size, after laying yellow-green, orange or yellow-orange. The caterpillar is 25-28 mm long, yellow-green, the chairman is light brown, on the back is a brown longitudinal strip, on the sides of the body, are three white stripes, three pairs of pectoral and two pairs of abdominal legs. Pupa – 12-13 mm, light brown, with a forked spine at the end of the abdomen, in an earthen cocoon.
Eggs hibernate on shoots at the base of the kidneys. Embryo development occurs in the fall and continues in the spring. Embryos that are not exposed to temperatures below 0 ° C cannot complete development. To complete embryonic development in the spring, the sum of effective temperatures of 79 ° C (at a threshold of 6 ° C) is required. Caterpillars revive about 10-12 days before the beginning of the flowering of the apple tree and feed on leaves and generative organs for 22-28 days. After completing feeding, the caterpillars descend on cobwebs and deepen into the ground by 5-10 cm, where they pupate in an earthen cradle. In the state of diapause, the pupa remains until autumn, for 3-4 months. In September-October butterflies come out. The favorable temperature for butterflies is 5-11 ° С. They endure short-term temperature drops to -15 ° C without much loss. Females move to a tree and after fertilization lay eggs one at a time or in small groups on young shoots. Fertility – 250-300 eggs. Embryonic development begins in the fall and stops in the phase of the embryonic band surrounded by the membranes, after which diapause sets in until the spring of next year. Annual generation.
The caterpillars of the winter moth roughly eat leaves, gnaw buds, flowers, and ovaries, braiding them in a cobweb. The number of winter moth limits the temperature maximum. For the caterpillar, the temperature optimum lies in the range of 14-18 ° C, for pupae – up to 18 ° C. At high temperatures, the mass death of the pest is observed. In winter, a drop in temperature to -35 … -40 ° C causes the death of eggs.
Species close to the winter moth in terms of developmental features are fruit moth and green bird cherry moth.
Protective measures. Early autumn plowing of the soil before the release of butterflies. Cultivation between the rows and loosening of the soil in the trunk circles after completion of the development of caterpillars. With a population exceeding 2-5 eggs per 1 m of branches, it is necessary to spray pesticides early in the spring, before buds open, at an air temperature of at least 4 ° C. During the mass revival of caterpillars at a density of 4-9 caterpillars per 1 m of branches – treatment of trees with insecticides or biological products