Flea beetles (small jumping bugs) do on leaves of cruciferous plant, small deepenings in an ulcer kind.
Most often from them meet: wavy, brightly-leg, sinuate, black, dark blue and a south crucifer flea beetle. Adult flea beetles winter under the fallen down leaves, under the vegetative rests, on a soil surface. Flea beetles in the early spring leave places of wintering. Flea beetles at first eat weeds. Further flea beetles attack shoots of cultural plants and sprouts. Sometimes flea beetles almost completely destroy shoots. Pericarps of cruciferous plant are damaged as well.
· Sinuate flea beetles oviposit in holes, which it gnaws out on roots;
· brightly-leg flea beetle - on leaves;
· other kinds of flea beetles - in soil.
Injuriousness of flea beetles especially increases at hot and dry weather in the spring. Larvae of flea beetles develop on roots, eating small roots. Larvae of flea beetle can eat round root crops at a neck. Larvae of brightly-leg flea beetles "mine" leaves.
Pupation of flea beetles occurs in soil. In the end of summer there is a new generation of flea beetles.
For protection the cabbage sprouts from damage by flea beetles, it should bed as early as possible. The techniques directed on acceleration of growth of plants (fertilizer application, dosing, watering, and dusting with a road dust with ashes), reduce injuriousness of flea beetles.