Red Turnip Beetle

species: entomoscelis americana
common names: red turnip beetle
hosts: cole crops
notes:

Agriculture and Agri-Food Canada Insect Identification Sheet No. 18 October l982

Red Turnip Beetle

Entomoscelis americana (Brown)

The red turnip beetle occurs in Western Canada with the exception of the coastal region of British Columbia.

Injury:

In the spring, red turnip beetles (adults and larvae) damage turnip, radish, rape, mustard and other cruciferous plants by feeding on the leaves, flowers, and stems of young plants. This may result in the death of the plants. Later, the adults damage the seed pods of mature plants. In rape and, mustard, this damage may cause premature shelling in the swath and loss of crop.

Life History:

The adult beetle is about 6 to 10 mm long and bright red. It has three black stripes down the back and a black patch just behind the head. Adult beetles appear from early June until early July. After feeding for about 2 to 3 weeks, they reenter the soil to aestivate for about 4 weeks and reappear on their food plants in late July or early August, mate and lay eggs. Their brownish orange eggs are laid in small clusters on the ground, in the shelter of leaves, or in debris near the plants where the adults have been feeding. The eggs are laid from early August to late October, overwinter in the soil, and hatch in early May. The larva is six legged, rough-skinned, covered with many short hairs, and about 9 mm long when fully grown. The upper part of the body is dark, smoky black, the underside brownish. Larvae may be found until approximately mid-June. When full grown, larvae develop into orange-colored pupae, at a depth of about 2.54 cm below the soil surface. After about 10 to 14 days, they emerge as adult beetles. There is one generation per year.

Pest Management:

Fall or early spring cultivation helps to control the red turnip beetle. Volunteer rape and weeds of the mustard family should be controlled, especially in summer fallow or stubble fields. For information on the control of this insect consult your provincial Department of Agriculture. Red Turnip Beetle, Entomoscelis americana Brown.

This is a sporadic pest in Central British Columbia, the Peace River, and at higher elevations in Southern British Columbia. It is mainly a pest of cabbage, radish, and rutabagas. They can feed on and survive on many weeds.

Vegetables Attacked:

Cole crops: broccoli, kohlrabi, brussels sprouts, radish, cabbage, rutabaga, cauliflower, turnip, kale.

Injury:

Adults and the larvae feed voraciously on flowers, seed pods and foliage. Large, ragged holes are chewed in the leaves; frequently only midribs and stems are left. Yield is reduced or the plants may be killed.

Insect:

Adults or beetles are 6 mm long, bright red with black patches on the head end and three lengthwise black lines on the wing covers. Eggs are bright red and elliptical. Young larva are orange with black spots; mature larva are black and 12 mm long.

Life History:

There is one generation a year. Eggs overwinter in the soil and hatch in early May. Larvae mature by late June and pupate in the soil. Adults emerge and feed for a short time until hot weather causes them to cease feeding and return to the soil. When temperatures cool in August and September, they re-emerge, feed and lay eggs. Adults remain on the plants until the first killing frost.

Control:

Insecticides should be applied when larval feeding damage is first observed.