Insect Pests

The asparagus beetle adult is slender, about 1/4 inch long, red and metallic blue-black with six yellow squares on its back. (There is also a spotted asparagus beetle with nearly identical shape and size that is reddish-orange or tan with 12 small black spots on its back.) - Clemson University USDA Cooperative Extension Slide Series, www.insectimages.org

Wrinkled, white to gray larvae with black heads feed on asparagus foliage, often stripping the plants. Continued feeding weakens the roots to reduce next year’s harvest. - Clemson University USDA Cooperative Extension Slide Series, www.insectimages.org

Both the adults and the larvae of asparagus beetle attack the spears and foliage of asparagus. Adults first appear in spring after emerging from spending winter in old stalks and protected places around the garden. They chew on asparagus shoots when they first come up in the spring and lay dark brown eggs on the stalks or foliage. The eggs hatch into larvae that grow about 1/2 inch long. The plants are often defoliated and stained with dark brown fluid. If you don’t control them, they weaken the plants by feeding for many weeks into the summer.

To control, use insecticidal soap at the first sign of their presence. For other controls, contact your county Extension service for products approved in your state.

To help prevent infestations, clean up the garden at the end of the season.