Cabbage stem flea beetle

Cabbage stem flea beetle has become more of a problem on Scottish winter oilseed rape crops.  The beetles are most noticeable in mid August/early September, often being caught up in the rape harvest.  The beetles won't damage the harvested seed, but they can cover trailers, wlls, machinery and seed in their thousands as they seek a way out of the store.

The beetles feed for 2-3 weeks on rape seedlings before they lay eggs near germinating rape plants.  The shot-holing of coteyledons and young leaves can lead to stunding of the crop.  From October onwards newly hatched larvae sek out young rape seedlings, and tunnel their way into the stem of the plant and occasionally the grouing point.  THis weakens the stems and allows water to enter their feeding tunnels which, when frosts occur, cause the leaves and stems to freeze, contributing to the winter loss of plants and foliage.

In the spring, infested plants will remain stunted and topple over if the stems are severely damaged.