Planting resistant varieties may also help. Apply chemical treatments as needed. Aphids cluster on the underside of leaves and suck sap, causing the foliage to curl, wilt, or become distorted. Plants may be killed or rendered unmarketable. Aphids are pale green and have cornicles, or points, on the abdomen.
Cabbage aphids have a gray, waxy coat and can be winged or wingless.
Cultural practices and the use of resistant varieties help prevent flea beetle infestations. Row covers physically protect seedbeds from these insects. Good weed control and the destruction of crop residue reduce overwintering populations. Planting resistant varieties may also help. Apply chemical treatments as needed.