Left: Coleomegilla maculata adult. J.Ogrodnick
Right: Early spring congregation of C. maculata. J.Ogrodnick

Coleomegilla maculata
(Coleoptera: Coccinellidae)

This lady beetle, a North American native, is found throughout most of New York, southern Ontario, and southern New England and across the south to the mid-western states. It can be very common and is sometimes called the pink spotted lady beetle.

Appearance

C. maculata, is a medium-sized (about 5-6 mm), pink to red, oval beetle with six spots on each forewing. The area behind the head is often pink or yellowish with two large triangular black marks. C. maculata larvae are dark and alligator-like with three pairs of prominent legs, growing to 5-6 mm in length. Eggs are spindle shaped and small, about 1 mm long.

Habitat (Crops)

Wheat, sorghum, alfalfa, soybeans, cotton, potatoes, sweet corn (tassels may supply both pollen and small prey), peas, beans, cole crops, tomatoes, asparagus, apples and other crops attacked by aphids and other reported prey.

Pests Attacked

C. maculata adults and larvae are important aphid predators but also prey on mites, insect eggs, and small larvae. Unlike most lady beetles, plant pollen may constitute up to 50% of the diet. Reported prey include pea, green peach, melon (cotton), cabbage, and potato aphids and greenbug; eggs of European corn borer, imported cabbageworm, fall webworm, and corn earworm; asparagus beetle, Mexican bean beetle, and Colorado potato beetle eggs and larvae. In trials to assess this lady beetle for control of Colorado potato beetle, it appeared to prefer aphids over beetle eggs and larvae.

Life Cycle

Adults overwinter in large aggregations beneath leaf litter and stones along hedgerows or in protected sites along crop borders, especially those of fields planted to corn in the previous season. They emerge from early to mid-spring and disperse, often by walking along the ground, to seek prey and egg laying sites in nearby crops.

Female lady beetles 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. Larvae grow from about 1 mm to 5-6 mm in length and may wander up to 12 m in search of prey. The larva attaches itself by the abdomen to a leaf or other surface to pupate. The pupal stage may last from 3 to 12 days depending on the temperature.

C. maculata adults may be found from April to late September and can be the most commonly observed lady beetles in corn, potatoes, and mixed crops. They may be especially abundant towards the end of the season when the adults aggregate in preparation for mating and winter hibernation. There are from two to five generations per year.

Conservation

Because pollen is an essential component of the diet of Coleomegilla, the planting or preservation of refuges, or interplantings, of early-flowering species with a high pollen load may be beneficial especially to provide a food source during late spring before the build up of aphids. Flowering dandelions, for example, have been recorded as a heavily used pollen source for dispersing adults in late spring potato fields.

Pesticide Susceptibility

Tolerance to some pesticides at recommended application rates is likely. Overwintering adults may be less susceptible than active adults and larvae.

Commercial Availability

Available commercially. See the off-site publication, Suppliers of Beneficial Organisms in North America. Also available through Entomos, LLC (info@entomos.com), 4445 SW 35th Terrace, Suite 310 Gainesville, Florida 32608, 352-371-6490, and through Integrated BioControl Systems, Inc., (goodbug@one.net), P.O. Box 96, Aurora, IN 47001-0096, 812-537-8673.*

Taken from:

Hoffmann, M.P. and Frodsham, A.C. (1993) Natural Enemies of Vegetable Insect Pests. Cooperative Extension, Cornell University, Ithaca, NY. 63 pp.

Additional References

Gordon, R.D., 1985, The Coccinellidae (Coleoptera) of America North of Mexico. J. NY Entomol. Soc., 93: 1-912.

Groden, E., Drummond, F.A., Casagrande, R.A., Haynes, D.L. Coleomegilla maculata (Coleoptera: Coccinellidae): its predation upon the Colorado potato beetle (Coleoptera: Chrysomelidae) and its incidence in potatoes and surrounding crops. J. Econ. Entomol., 83: 1306-1315.

Hazzard, R.V., Ferro, D.N., VanDriesche, R.G., Tuttle, A.F. (1991) Mortality of eggs of Colorado potato beetle (Coleoptera: Chrysomelidae) from predation by Coleomegilla maculata (Coleoptera: Coccinellidae). Environ. Entomol., 20: 841-848.

Rice, M.E., Wilde, G.E. (1991) Aphid predators associated with conventional- and conservation-tillage winter wheat. J. Kans. Entomol. Soc., 64: 245-250.

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