Species

Lady beetles, commonly called "ladybugs," belong to the order Coleoptera and family Coccinellidae. The convergent lady beetle (Hippodamia convergens) is among the most common. Their role as a natural predator of soft-bodied insects such as aphids is well known.

Leaf beetles of the family Chrysomelidae are common pests that can be mistaken for lady beetles because of their similar dome shape. Lady beetles have shorter antennae, which have a clubbed end. Also, leaf beetles have four tarsal (foot) segments, while lady beetles typically have three.

Identification

Life Cycle

Eggs are laid early in spring. Females can lay up to 1,000 eggs during the spring and early summer. Eggs are oblong in shape and attached to leaves. Some are laid individually, others in clusters. After hatching, the larvae go through four instars which last between 20-30 days before attaching themselves to a leaf to pupate and become adult lady beetles. Development from egg to adult takes 3-6 weeks with an overall lifespan between 3-12 months.

Prey

Lady beetles prey on soft-shelled pests including:
Aphids
Mites
Mealybugs
Thrips
Moth eggs
Beetle eggs
Cottony-cushion scale

Function

Both the larvae and adult beetles are predators. However, they differ in they way that they attack and feed on prey. The larvae pierce and suck out the contents of their prey while adults will consume their prey in its entirety. Both larvae and adults are active predators that travel throughout areas hunting for prey. Healthy populations of lady beetles are known to effectively destroy aphid infestations, with each beetle consuming upwards of 500 aphids per month.

Commercial Availability

Lady beetles are commercially available for purchase from several distributors.

Handling and Use

Purchased lady beetles can be stored in the refrigerator (not the freezer), periodically warmed up and misted with water, then returned to the refrigerator. This way, smaller amounts can be released on plants as needed. Release in the evening and after setting a water source nearby to encourage lady beetles to stay on site.

Keep in mind that lady beetles are genetically programmed to fly a distance following waking from dormancy. Don't be surprised if some of your beetles fly out of your garden at first. Repeated releases may be necessary.

Cultivation Techniques

When practical, allow weeds in the garden such as dandelion, wild carrot, and yarrow, which can attract lady beetles. Lady beetles like pollen and nectar from flowers such as angelica, alfalfa, coffee berry, Mexican tea, evergreen euonymus, goldenrod, dill and fennel and/or grains like buckwheat.

When aphids and other prey are unavailable some species of lady beetles feed on pollen, nectar from flowering plants, or artificial foods such as the product Wheast,

Refer to Farmer Fred's Guide for suggestions on plants to include in your garden to naturally attract these beetles.

References

Antonelli, Arthur. "Lady Beetles." 2003. Washington State University Cooperative Extension. 12 Nov. 2008.
< http://www.puyallup.wsu.edu/plantclinic/resources/pdf/pls85ladybeetles.pdf>.

Flint, Mary Louise, and Steve H. Dreistadt. Natural Enemies Handbook: The Illustrated Guide to Biological Pest Control. Berkeley: UC Division of Agriculture and Natural Resources and the University of California Press, 1998.

Weeden, C.R., A. M. Shelton, and M. P. Hoffman. "Lady Beetles." Biological Control: A Guide to Natural Enemies in North America. 12 Nov 2008
< http://www.nysaes.cornell.edu/ent/biocontrol/predators/ladybintro.html >.