University of Illinois Extension
Bruce Spangeberg

These articles are written to apply to the northeastern corner of Illinois. Problems and timing may not apply outside of this area.

Stateline Yard & Garden

Ladybugs Common These Days

October 29, 1998

With several mild, sunny days over the past few weeks, anyone outdoors most likely has seen a few ladybugs. In some locations, dozens and dozens have been converging on south or west walls of home or garages. Perhaps in raking leaves, you may have found a cluster of ladybugs at the base of a shrub. In either case, these insects are preparing for winter.

The very visible ladybug flying around is often the multicolored Asian lady beetle, a newer species to Illinois and the upper midwest. These insects range from 1/4 to 3/8 inch long, and typically have orange wing covers with 19 black spots. However, multicolor is in the name because of wide color variation from no spots to 19 and various shades of color to the wing covers. In all cases, the area behind the head is black with white areas on the sides.

The multicolored Asian lady beetle species migrates to cliffs in its native Asia to overwinter in cracks and crevices. Not finding any cliffs here, the insect goes to buildings instead. This is why they are common in and around homes this time of year.

This insect was introduced into the northeastern United States earlier this century from China and Japan. As with other lady beetles, it feeds heavily on aphids and other small, soft-bodied insects, making it beneficial.

Lady beetles will not reproduce indoors and do not feed. As is the case with boxelder bugs, these insects are only indoors for shelter to overwinter, and will find their way back outdoors in spring. They will feed on aphids and other insect pests.

When cleaning up fallen leaves around shrubs, it’s common to run across a cluster or two of lady beetles in them. Many of the native species overwinter in debris such as leaves around the bases of shrubs, so do them a favor and maybe allow a few leaves trapped near the base of shrubs here and there to sit until spring for the lady beetle to overwinter successfully.

Since these insects are beneficial, use restraint in killing them. Restrict entry by caulking or using weather stripping to seal cracks and crevices. If needed, remove by hand or vacuuming when found indoors. Spraying insecticides is not suggested.

 

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