Asparagus Beetles

Family: Chrysomelidae (Crioceris asparagi)

Description

The beetle is 6 mm to 9.5 mm long and slightly elongated. Adults are metallic blue-brown in colour with cream spots on their red-bordered wing cover. The larvae are gray grubs with dark heads and three pairs of brown legs. The eggs are shiny dark rods 3 mm long and are laid in rows of 3 to 10 eggs, on the asparagus plants.

Life Cycle

The life cycle of the asparagus beetle has four stages: Egg, Larva, Pupa, and Adult. Adult beetles emerge in the early season and colonize asparagus fields to mate, feed, and lay eggs.  The eggs are laid on the branches and leaves of the asparagus plants, and hatch within a week depending on the temperature. Larvae feed in spears and ferns, and when mature, fall to the ground to transform into pupae. About a week later, adults emerge to start another generation. There are 2-3 generations each season, with the first generation producing the most eggs.

Damage

Common asparagus beetle is an important pest of Asparagus crops, and it is its only food plant. It frequently occurs earlier in the season wherever asparagus is grown. The adults feed on the asparagus spears and cause browning and scarring. Once the ferns appear after the harvest of asparagus, the larvae and adults can also chew the ferns. Beetles feeding on the ferns weaken the plant and reduce the plant’s ability to provide sufficient nutrients for the following season. Fewer ferns also make asparagus a target for Fusarium, a fungal disease. Moreover, the presence of common asparagus beetle eggs on the spears can make the asparagus unappealing.

Control

Advice