The sevenspotted lady beetle, repeatedly introduced to North America from Europe for the biological control of aphids, was established in the early 1970s in New Jersey, apparently from an accidental introduction. It has since spread naturally or been introduced to many northeastern and north central states. C. septempunctata may be a more effective predator than some native lady beetle species, displacing them in some areas.
Comparatively large (7-8 mm) with a white or pale spot on either side of the head. The body is oval, and has a domed shape. The spot pattern is usually 1-4-2, black on the orange or red forewings. Lady beetle larvae are dark and alligator-like with three pairs of prominent legs, growing to 7-8 mm in length. Eggs are spindle shaped and small, about 1 mm long.
Aphid infested crops, including potatoes, legumes, sweet corn, alfalfa, wheat, sorghum, and pecans.
Reported prey include pea, cowpea, green peach, potato, corn leaf, melon aphids, and greenbug.
Adults overwinter in protected sites near the fields where they fed and reproduced. In spring, emerging beetles feed on aphids before laying eggs. Females may lay from 200 to more than 1,000 eggs over a one to three month period commencing in spring or early summer. Eggs are usually deposited near prey such as aphids, often in small clusters in protected sites on leaves and stems. The eggs are small (about 1 mm) and spindle-shaped.
C. septempunctata larvae grow from about 1 mm to 4-7 mm in length over a 10 to 30 day period depending on the supply of aphids. Large larvae may travel up to 12 m in search of prey. A second generation may appear about a month later. The pupal stage may last from three to 12 days depending on the temperature.
In the northeastern United States, there are one to two generations per year before the adults enter winter hibernation. Development from egg to adult may take only two to three weeks, and adults, most abundant in mid- to late summer, live for weeks or months, depending on the location, availability of prey, and time of year.
C. septempunctata is spreading to new areas each season. Conservation can best be accomplished by following integrated pest management guidelines as outlined in the tutorial of this guide.
Tolerance to some pesticides at recommended application rates is likely. Overwintering adults may be less susceptible than active adults and larvae.
This species has been mass reared, but at this time is not commercially available.
Hoffmann, M.P. and Frodsham, A.C. (1993) Natural Enemies of Vegetable Insect Pests. Cooperative Extension, Cornell University, Ithaca, NY. 63 pp.
Gordon, R.D. (1985) The Coccinellidae (Coleoptera) of America North of Mexico. J. NY Entomol. Soc., 93: 1-912.
Habeck, D.H., Bennett, F.D., and Frank, J.H. (1990) Classical Biological Control in the Southern United States. Southern Cooperative Series Bulletin No. 355, IFAS Editorial, University of Florida, Gainesville, FL. 197 pp.