The Common Asparagus Beetle (Crioceris Asparagi) is by far the most troublesome of the insect enemies of asparagus. Both the larvae and the beetles feed on the shoots, which are thus lowered in market value or rendered unfit for commercial purposes. They also feed on stems and leaves of old and young plants, which they defoliate and greatly reduce in vitality.
The beetles winter under any convenient shelter and lay eggs for the first brood in April or May. The eggs are deposited in groups of two or more, upon leaves or stems. The larvae emerge in three to eight days, begin to feed at once and attain full growth in 10 to 14 days. Chittenden ("Insects Injurious to Vegetables") describes the beetle as "a most beautiful creature, slender and graceful in form, blue-black in color, with red thorax, and lemon-yellow and dark-blue elytra or wing covers, with reddish border. Its length is a trifle less than inch." Two and frequently three broods are produced in a season.
Various methods are employed to control this insect. Arsenate of lead is effective in destroying both slugs and beetles. It may be used with safety on young plants, in old plantations after the cutting season, and on lure plants. When shoots are cut every day, and there are no other plants in close proximity, all the eggs are destroyed when the stalks are cut and sent to market. Coops of chickens are sometimes kept in the fields to feed on the beetles and slugs. The plan is considered excellent when properly managed. Fresh air-slaked lime kills the larvae, and when they are brushed to the ground in hot weather they die before they can get back on the plants.