Crop Clinic

Over the last few seasons, a suite of ‘new’ pests of winter rape have been making an appearance, and time has shown that they are not ‘one-off’ occurrences but are here to stay.

Typically the only pests that you used to worry about on winter oilseed rape were slugs and flea beetles.

 Now there is the added threat from cabbage stem flea beetles, rape winter stem weevils and aphicide-resistant peach-potato aphids.

The flea beetles and slugs will attack germinating plants, causing poor establishment and even killing off plants. Slugs like soil conditions to be moist and tend to eat larger holes out of the leaves than the flea beetles, which prefer drier conditions.
There is an added problem with cabbage stem flea beetle as it will lay eggs on or near to plants and the resulting grub will burrow into the stem of the plant and feed overwinter.

If during this seasons oilseed rape harvest you find many blue-black beetles on the sides of the trailer or on the walls of your stores after the seed has been taken in, then this is a sign that you may have a potential problem with cabbage stem flea beetle on autumn sown rape this year.

 We would welcome any reports of cabbage stem flea beetles being seen at harvest, especially from north of the Forth.

Rape winter stem weevil also lays eggs on plants from late September onwards, and their grubs also burrow down the stem to the crown of the plant, feeding over the winter months.