Insects and Pests
Cabbage Stem Flea Beetle
Cabbage stem flea beetle is a serious pest of oilseed rape. Larval feed in the stems and petioles which reduces vigour and may ultimately lead to stunting or plant death. Adults are 3-5 mm long and are have a distinctive metallic blue-black appearance.
Adults migrate into the crop, feed on leaves and mate. After eggs hatch larvae feed on the main stem behind the growing point before dropping to the soil to pupate.
A wet season will likely increase slug pressure as wet soils help slugs move around and also help egg survival. Crops should be monitored regularly from emergence to see if control is warranted. Use slug bait traps to determine the numbers present and if there are 4 or more per trap then consider treatment. Rolling the seed bed is an important to control slugs as this restricts their movement between soil particles.
Pollen beetle may cause problems at green bud stage where they burrow into the bud and consequently killing it. However they quickly become beneficial to the crop after flowering has commenced as they help pollination of the flowers.