How to Manage Pests

Identification: Natural Enemies Gallery

Convergent lady beetle

Scientific name: Hippodamia convergens

Phylum: Arthropoda Class: Insecta Order: Coleoptera Family: Coccinellidae Common prey: Predaceous on aphids and occasionally other soft-bodied homopterans. Used for aphid control in roses. Can be important in every crop with aphid pests. Commercially available: Yes Life Cycle

DESCRIPTION

Lady beetles are easily recognized by their shiny, convex, half-dome shape and short, clubbed antennae. Most lady beetles, including this species, are predaceous as both larvae and adults. Young lady beetle larvae usually pierce and suck the contents from their prey. Older larvae and adults chew and consume their entire prey. Larvae are active, elongate, have long legs, and resemble tiny alligators. Many lady beetles look alike and accurate identification requires a specialist.

Adult convergent lady beetles measure 4-7 mm (<1/4 inch) long and have orange to red forewings, with up to 13 black spots; however, many individuals have fewer spots and some have none. The thorax is black with two converging white lines inside and a white margin. The elongated larvae grow up to 7 mm (1/4 inch) long and are blackish with orange spots. Eggs are oblong, yellow, measure about 1 mm (1/25 in) in length and are laid on end in groups on leaves and stems near aphids. Pupation occurs in sheltered places on stems or other substrates. Convergent lady beetles undergo complete metamorphosis and have one or two generations per year.

Both adults and larvae of H. convergens feed primarily on aphids and occasionally on whiteflies, other soft-bodied insects and insect eggs. In California, many Hippodamia species overwinter in large aggregations in the Sierra Nevada. In the spring, adults fly down from the mountains to coastal and valley areas. Commercially available Hippodamia are collected at overwintering sites and can be bought and released. Unfortunately, lady beetles have the tendency to disperse once they are released, even if food is abundant. Although they are extremely important natural enemies of aphids, their propensity to disperse makes it difficult for them to be used in inoculative or inundative biological control programs.

See also: Lady Beetle Releases for Aphid Control: How to Help Them Work (PDF )

Research articles on lady beetle releases:

• Flint, M.L. and S.H. Dreistadt. 2005. Interactions among convergent lady beetle (Hippodamia convergens) releases, aphid populations and rose cultivar. (PDF ) Biological Control 34 (2005): 38-46.
• Flint, M.L.; S.H. Dreistadt, J. Rentner, M.P. Parrella. 1995. Lady beetle release controls aphids on potted plants. California Agriculture 49(2): 5-8.

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