INTRODUCTION
Red turnip beetles, Entomoscelis americana, are typically associated with plants from the mustard family (also known as crucifers or Brassicaceae). They are more prevalent in areas with sandy soils. Red turnip beetles may migrate into home gardens from nearby fields where plants from the mustard family are currently growing or were growing in previous years.

IDENTIFICATION AND LIFE CYCLE
Red turnip beetles overwinter in the soil as oblong, reddish-brown eggs. The eggs hatch starting in March and continue hatching until early May.

The larvae feed on vegetables and weeds from the mustard family such as cabbages, turnips, flixweed, shepherd's-purse, and wild mustard. Mature larvae are black, about ½ inch long with a rough skin and short hairs covering a segmented body. The larvae feed primarily at night although they have been observed during the day. If disturbed, they will drop to the ground and readily blend in with the soil. After feeding for about three weeks, the larvae form bright orange pupae within the top inch of the soil. Pupation takes about 2-3 weeks.

Adults emerge and appear in gardens from early June until early July. The adult beetles are about ½ inch long, bright red with three black strips that run lengthwise down its back. The head is red with one large black patch and smaller black spots on the edges. The adults feed for 2-3 weeks. They feed on plants from the mustard family such as turnips, cabbages, radish, kohlrabi, hoary alyssum, sweet alyssum, and wild mustard. They have also been reported on strawberries, dandelion, beans, and potatoes which are from other plant families.

From late June to mid-July, the adults burrow into the soil to rest for about one month. They re-emerge in late July or early August. The adults feed, mate, and lay eggs until late October. The eggs are laid singly or in clusters in shallow depressions in the soil or underneath leaves or other debris left on the soil. Each female produces about 300 to 400 eggs. There is one generation per year.

DAMAGE
In spring, both the larvae and adults feed on leaves, stems, and flowers. The extent of the damage depends on population levels. The damage can consist of light feeding to defoliation of the entire plant which can stunt or even kill it. Young seedlings and transplants are the most susceptible to injury from heavy feeding. Older plants can tolerate more severe defoliation. Later in the summer when only adults are present, the densities are usually not high enough to cause significant damage. Red turnip beetles are usually not an annual problem in home gardens and high numbers occur sporadically over the years.

MANAGEMENT
Cultural Control
Rototill or rake the soil in fall or early spring to bury the eggs. When the eggs hatch in spring, the larvae are unable to climb out of the soil to reach host plants. Cultivation from mid-May through June exposes the pupae to desiccation (drying out) and predation.

Plants from the mustard family are a primary food source for the emerging larvae. Eliminating weeds from the mustard family may help to reduce the number of red turnip beetles.

Physical Control
If only a few plants are affected, handpick and kill the larvae and adults (e.g., drop them into a pail of soapy water).

Chemical Control
If cultural and physical methods do not provide adequate control, using a residual insecticide may be necessary. Common products include carbaryl (e.g., Sevin) or permethrin (e.g., Eight).

When treating any vegetables with an insecticide, you often have to wait for a specified number of days before you can harvest and eat them. Read the label to determine the number of days between insecticide application and harvest for the specific vegetable that you have treated.

CAUTION: Read all label directions very carefully before purchasing and again before using an insecticide. Information on the label should be used as the final authority. Treat only plants listed on the label of the insecticide.

This publication was modified from a Department of Entomology University Minnesota publication entitled Red Turnip Beetle by A. Genetzky, E.C. Burkness, and W.D. Hutchison.

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