Pest Type: Grape Pest
Row: Coleoptera – Coleoptera
Family: Weevils – Curculionidae
It is found in the south, especially harmful in areas of the southern coast. Damages grapes, less often fruit trees and berry bushes.
Beetle 8-11 mm long, black on top, elytra convex, with small longitudinal grooves, spaces between grooves in transverse wavy wrinkles; the rostrum is short, thick, there are no lower wings, so the beetles do not fly. The body of the males is narrower, the hind femora are greatly expanded to the apex. Egg size 0.6-0.7 mm, oval, tan. Larva 10-12 mm long, light yellow, arched, curved, wrinkled, covered with sparse hard hairs, chairman brown. Pupa – 10-11 mm, white, with two spines on top of the abdomen.
Immature beetles overwinter, as well as larvae that have not completed development, in the soil and under plant debris. They leave wintering places in April at an average daily temperature of 10-12 ° C. Additionally they feed on grape buds, almond leaves, mountain ash, apple trees, roses. In warm weather, a beetle can destroy 5-7 kidneys per night. With the advent of vine leaves, beetles eat them until late autumn. They lead a nocturnal lifestyle, hide during the day.
3-6 days after leaving the wintering places, the beetles begin to mate. Mating lasts all summer. In late May and early June, egg-laying begins, which lasts until September. Eggs are laid one at a time or in small groups in the soil to a depth of 10-18 cm. Having revived after 10-12 days, the larvae feed on humus and plant debris, and later on the roots of the vine. Larvae live depending on soil moisture, at a depth of 10 to 30 cm. The drier the soil, the deeper the larvae. They molt 6 times, passing 7 centuries. The larvae, which revived at the end of May – in June, manage to complete development and pupate. Those born later remain in the soil until the spring of next year. The development of the pupa takes 11-16 days. Beetles who come out join the old, additionally feed on leaves and lay eggs in 20-25 days. The larvae regenerated from them remain for the winter in the soil. In October, when the average daily temperature drops to 10 ° С, all beetles go to winter. Beetles live 2-3 years, during which they lay only up to 1,500 eggs.
The number of Skosar is reduced by predators – large ground beetles, lizards, frogs, birds. The eggs are eaten by ants.
Protective measures. Autumn, summer, spring soil cultivation. With a population of more than 2-3 larvae per 1 m2, the introduction of insecticides into the soil. If there are three beetles per bush, two treatments with insecticides are carried out: during the period of nabubninna and blooming of the kidneys and during the mass exit of beetles.