Spotted Asparagus Beetle

species: criocerus duodecimpunctata
common names: spotted asparagus beetle
hosts: asparagus
notes:

THE FOLLOWING (UNTIL OTHERWISE NOTED) IS FROM: GERBER, H.S. 1983.
MAJOR INSECT AND ALLIED PESTS OF VEGETABLES IN BRITISH COLUMBIA.
MINISTRY OF AGRICULTURE AND FOOD.

Spotted Asparagus Beetle

Criocerus duodecimpunctata (Linnaeus)

Occurs in the Okanagan and Similkameen Valleys. It is spreading rapidly to new asparagus plantings in these areas.

Vegetables Attacked:

Asparagus

Injury:

Adults chew rough channels in young shoots or spears. They feed most extensively on frond growth. Attacked green surface tissue is killed. Whole plants may be damaged, being left brown and bare. Severe defoliation will reduce plant vigor. Larvae feed mainly in the berries, causing little damage.

Insect:

Adults are 6 mm long, slender, reddish-orange, with six black spots on each wing cover. Dark-green eggs are laid singly on the frond growth. Orange larva are 8 mm long when mature.

Life History:

There are two generations a year. Adults overwinter in sheltered locations beneath plant debris. They emerge later than the asparagus beetle. Eggs are laid when the asparagus is in bloom. Larvae hatch in one to two weeks. Mature larvae pupate in the soil. First-generation adults emerge about mid-July and second-generation adults in late August.

Control:

Apply insecticides when beetles are observed on the shoots of producing asparagus or when first observed on the frond growth of seedlings. Community-wide control, removal of asparagus volunteers, and burning or burying plant refuse in the fall will reduce insect damage. In small plantings, removal and destruction of the berries will give control.