The asparagus beetle is tough to control because your asparagus is growing in a permanent bed, so it is easier for the beetle to reproduce and come back and pester you year after year. The asparagus beetle is blue-black with four white spots and reddish margins. It has an oblong shape and is 1/4 inch long. It chews on leaves, fruit, and spears. The larvae are greenish gray, hump-backed grubs with dark heads. This insect has a noticeable behavior that helps you confirm its presence. When you see an asparagus beetle on the stem of a frond or on the spear, as soon as you approach the plant, the beetle immediately moves to the other side of the stem or the spear. It plays hide and seek with you. This insect is found throughout the United States.
The spotted asparagus beetle is red or brownish with 12 black spots on the back. Its eggs are dark brown and are laid on leaves. The larvae are orange with a black head and legs.
Emergence Time - Adult beetles over-winter in garden trash and emerge in spring to lay eggs on spears. The eggs hatch in about a week.
Symptoms of Asparagus Beetle Asparagus plants are defoliated, and young spears are misshapen.