Asparagus Beetle, Spotted
The common and spotted asparagus beetles are both less than 3/8" long.
The common asparagus beetle (CAB) has a bluish-black body with cream-colored, square or rectangular spots, while the spotted asparagus beetle (SAB) is tan to orange with 12 round, black spots.
The common and spotted asparagus bettels overwinter as adults in protected areas along fields, feed on spears and ferns, pupate in the soil and have 2 to 3 generations per year. Adult feeding on spears or the presence of eggs can render the crop unmarketable.
Grey CAB larvae may cause severe defoliation of ferns and decline of the planting, while yellow or orange SAB larvae only feed on berries. Scout for adults and eggs on sunny afternoons.
Treat spears if >10% of the plants are infested with beetles or 1 to 2% have eggs or damage. Treat ferns if 50 to 75% are infested.
If possible spot spray along edges of planting where overwintering adults colonize the field and/or band insecticide over the row to help spare natural enemies. Disk old ferns lightly in the fall and clean areas around planting of debris to reduce overwintering populations. Eliminating female plants, and thus berries, can reduce or eliminate SAB populations.
Use selective insecticides on ferns.
For Current information on production methods (including varieties, spacing, seeding, and fertility), weed, disease, and insect management, please visit the New England Vegetable Management Guide website.
Identifying and Enhancing Natural Enemies in Vegetable Crops
Insects
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