Any openings invite ladybug problem

The annual gathering of the ladybugs has begun. If your home has been invaded by swarms before, expect a repeat appearance. The insects are seeking winter refuge and want to get into the attic, wall cavities and interiors, by the thousands.

This is not to be encouraged: The insects can smother interior sills and walls and, when disturbed, secrete a smelly yellow fluid that stains furnishings and paint. The key to ladybug-human harmony is, frankly, exclusion.

Experts advise that you (or your handyman) examine the exterior of your home for cracks, holes and gaps that might provide an entryway. Caulk cracks and unsealed joints, especially around vents and windows; apply weatherstripping to leaky windows and doors; and attach screening to open attic and soffit vents.

If the beetles make it inside, you can sweep them up or use a vacuum cleaner to collect them, though that may trigger the yellow secretions.

The swarming is associated with a species of beetle relatively new to these shores, the multicolored Asian lady beetle. In its native Korea and Japan, it gathers in the fall to find winter nesting sites in limestone cliffs. The beetles see an exposed, brightly colored, west-facing house wall as merely a cozy bluff.

Organic gardeners pay good money for ladybugs, which are predators of aphids. Aphid species are major pests that attack shade trees and garden plants. If you want to harbor your own ladybug swarm, take the vacuum bag to a toolshed or the like, where the bag should be cut open to allow the bugs to find a place to cool down and become inactive for the winter, said Michael Raupp, entomologist at the University of Maryland.