Biology and Habits

Asian lady beetles are a species of ladybird beetle that was introduced to the US from Eastern Asia as an effort to control crop pests. Asian lady beetles are voracious predators of scale insects, mealy bugs, and aphids.  In fall, large aggregations of adult beetles accumulate near protected places to overwinter. Such locations include under rocks, leaves, and wood. On occasion, they invade homes and buildings, being particularly attracted to light colored walls on the south and west side. They enter cracks and crevices, through attic ventilation, or gaps around utility lines. On warm days in winter and summer, the beetles may reawaken and emerge into living spaces. 

Control

Prior to fall it is recommended to seal openings around attic vents or other cracks or crevices with caulk or fine mesh screening. If necessary, treat these areas or anywhere that clusters of Asian lady beetles are found with an appropriately labeled liquid insecticide. Dusting inside of cracks and crevices can be effective. Indoors, it is recommended to seal as many gaps in the ceiling or walls as possible. Since populations regularly fluctuate, Asian lady beetles may not reinfest a home or building the following year.