Pest Type: Cabbage Pest
Row: Coleoptera – Coleoptera
Family: leaf beetles – Chrysomelidae
It occurs in the steppe and forest-steppe zones. Damages cabbage, canola, radishes, swede, mustard, and other cabbage plants.
Beetle 7-10 mm in size, elongated oval; yellow-black on top with longitudinal black stripes along the seam and in the middle of the elytra; scutellum, the middle part of anterior and with 11 segments, black antennae. Egg size 2.0-2.5 mm, black-brown, oblong; its surface is hard. The larva is 13-16 mm long, the dorsal surface is brownish brown, the abdomen is yellow, the body is covered with dark warts and tubercles, on which the bristles are placed (caustic, sticky substance is released when touched with warts). Pupa 9 mm yellow-black.
A rapeseed leaf beetle hibernates in the egg stage, and sometimes larvae in the surface soil layer. Larvae hatch in the south – in early April, in the north – in the first decade of May, feed on cabbage weeds, often of different species. In the case of mass propagation, they damage cultural plants (cabbage, radish, etc.), eat out the flesh of leaves, leaving thick veins. Larvae develop 15-28 days. Pelletize in the soil at a depth of 5-8 cm in dense cocoons.
Pupa develops for 14-20 days. At the end of May – in June there are beetles that feed on leaves, flowers, and pods of various cabbage plants. In summer, at high average daily air temperatures, beetles burrow into the soil to a depth of 15-20 cm, where they are in the state of summer rest until autumn. At the end of August – in September, beetles come to the surface of the soil, feed on various cabbage plants, then mate. Females lay eggs in the surface soil from August to November. Fertility is 180-250 eggs.
In autumn, larvae that are in the soil until spring can hatch from early laid eggs. One generation develops per year.
Protective measures. Autumn soil cultivation. Destruction of cabbage weeds. Loosening the soil between the rows. In the case of 10% of plants being populated by the pest and with an average density of 5-6 or more individuals, insecticides are sprayed on one plant.