Be on the lookout for asparagus beetles. Both the adult and larvae of asparagus beetles feed on asparagus spears by chewing the tips and spear surfaces, leading to scarring and staining of the spear tips. Asparagus beetles overwinter as adults in trash near the garden. The adults are a blue/black beetle with a red prothorax with yellow spots. The larvae are a soft, greenish grub. Small, elongated, black eggs — sticking out long ways from the side of asparagus spears — are laid on developing spears.
Early control of beetles is important to reduce feeding damage later. Permethrin will provide control but requires a 3-day waiting period between spraying and harvest. Permethrin is found in Garden and Farm Insect Control and Eight Vegetable, Fruit & Flower Concentrate.
Ward Upham, Extension Agent
