Pest Type: Cabbage Pest
It is found everywhere. It damages cabbage, radish, rapeseed, turnip, turnip, less often wild cabbage.
Beetle 2.2-3.0 mm in size, black, covered with light scales and hairs, the head tube is thin, bend under the chest. Egg 0.5 mm in size, round oval, white, shiny. Larva-up to 4 mm, white, somewhat curved, with a brown head, without legs.
Pupa 2.5 mm, light yellow. Beetles overwinter in the surface soil layer and under plant debris in the fields where they fed. They wake up in April at an average daily air temperature of 7-8 ° С and additionally eat first on weeds, and then on the testes of cabbage, radish, and other cabbage plants.
Adults gnaw out small stems in the stems, pedicels, and buds. After 10-15 days, the beetle’s mate. In May and early June, the female lays eggs, one or two, one inside the young pods. The ovipositor is stretched for 20-30 days. The fertility of the female is 30-50 eggs. After 7-10 days, larvae hatch, which feeds on young seeds, gnawing them outside orbiting inside.
One larva during the development period can damage 6-9 seeds. Externally populated pods are almost no different from healthy ones. After 25-30 days, the larvae complete their development, gnaw a hole in the walls of the pod, fall onto the soil and pupate at a depth of 2-4 cm. In July, new-generation beetles that feed on cabbage weeds come out. In autumn they fly to wintering places. One generation develops per year. The abundance of the seed crypto-venom is reduced by the parasites Aneuclis melanarius Hobmgr.
Protective measures. Compliance with spatial isolation when placing testes (from 500 m to 1 km). Destruction of cabbage weeds. Deep autumnal plowing of fields that were occupied by the testes. Loosening of the soil during the period of mass pupation of larvae. When 10% of plants with 2-3 beetles per population are populated during the period of bud formation, it is recommended that the plants be treated with insecticides.