Aggregating Asian Lady Beetles

Eventhough this is a beneficial predator of aphids and scales, the multi-colored Asian ladybeetle tends to congregate in large numbers around buildings as they overwinter. This causes them to sometimes move indoors in the cooler months, where they can crawl on floors, walls and ceilings. They will exude a yellowish liquid when disturbed (reflux bleeding), which can stain fabric and can cause skin irritation. They can also bite since they have chewing mouthparts.
Exclusion practices should be used to prevent these ladybeetles from entering into buildings. All cracks and crevices, such as around windows, doors, air conditioners, and utility pipes should be sealed in late summer and fall. Also if beetles are spotted inside the home, then a vacuum should be used to remove them. Remember to dispose of the vacuum bag outside, so the beetles do not escape and re-invade the building.

Multi-colored Asian Ladybeetle. Photo by Mike Merchant, Professor and Extension Entomologist, Texas A&M University.