Rape Beetle

(Meligethes aeneus), a beetle of the family Niti-dulidae; a dangerous pest of seed-bearing cruciferous plants. The elongate and flat body has a length of 1.5 to 2.7 mm and is black with a metallic blue or greenish sheen. The larva, which reaches a length of 4 mm, is light gray and has three pairs of legs and a brown head.

The rape beetle is widespread throughout the USSR and yields one generation a year in northern regions and two or three in southern regions. The beetle, which winters in the soil or under plant remains, appears in April or May and feeds on the flowers of such early-blossoming plants as coltsfoot, dandelion, buttercup, wintercress, cherry, and apple. When the flower buds of crucifers appear, the rape beetle resettles on them. It eats the stamens, pistils, and petals—all of which usually yellow and fall from the plant. The larvae feed on pollen and sometimes damage the pistils. The principal damage is done by the beetles, which cause seed losses from 25 to 75 percent.

Control measures include proper crop rotation and spacing of seed-bearing plants, preplanting preparation and early setting out of seed-bearing plants, implementing measures to ensure rapid and uniform flowering, and loosening the soil between rows during pupation of the larvae. During incidences of large beetle populations, the plants should be treated with insecticides during flower budding.