The Asian lady beetle Harmonia axyridis , is a common and widespread wintertime household pest across all of Iowa and most of the United States. Large numbers of these insects invade homes during the fall and remain active over the winter, especially in late winter when temperatures warm and days get longer. Ladybugs do not feed and cannot reproduce indoors; they have not multiplied indoors although it must seem that way to homeowners who have been inundated with them. When lady beetles stranded indoors for the winter are emerging from inside house walls, there is no control option more practical or effective than repeated vacuuming. Spraying insecticides has little or no effect. One available trap is essentially a cardboard box with a sticky inner covering that captures beetles that wander inside it.
Asian Lady Beetle Infestation of Structures
Asian Lady Beetles: How to Get Rid of Ladybugs, Diet, etc.
Large numbers of lady beetles ladybugs infesting homes and buildings in the United States were first reported in the early s. Ladybugs normally are considered beneficial since they live outdoors and feed on plant pests. One species of lady beetle, Harmonia axyridis , can be a nuisance however, when they fly to buildings in search of overwintering sites and end up indoors. Once inside they crawl about on windows, walls, attics, etc. In many areas of the U. The beetle is native to Asia e.
Lady Beetle Traps
Adults are 4 to 8 mm. Variable elytra coloration with no spots or up to 10 spots. Yellow pronotum possesses up to 5 black spots forming an M-shape or trapezoid pattern. Larvae are black with bi-lateral orange sawtoothed bands.
Outdoors, Asian lady beetles helpfully feed on plant pests like aphids and many others. From September to November, they move indoors to overwinter, crawling along windows and walls. Small cracks around windows and door frames provide entry points.