Samhain has come and gone. But, there may still be some “trick or treaters” at your house.
The Asian multicolored ladybird beetle, also known as the Halloween ladybird beetle, may be trying to find a nice, warm, comfortable place to spend the winter. If it was only one or two wanting to come into your house, it wouldn’t be much of a problem and I wouldn’t be writing about them.
However, when one finds a nice place to hunker down for the winter, it sends out a call to all of its friends and they begin showing up, sometimes in the thousands. Now, this beetle doesn’t injure people or pets. They don’t harbor any diseases communicable to us or our pets. They rarely bite and they don’t breed indoors. So, what’s the problem?
Throughout the warmer months, these colorful beetles supply us with a cost-free benefit. They happily consume their body weight in aphids every day. But, when the weather begins to cool, they resort to their instinct to congregate in the cracks and crevices of cliff faces. Unfortunately, we have no cliff faces in our neck of the woods.
The beetles have found an alternative: our homes. They are attracted to the sunny sides of light colored structures. At night, they come to lights. If the beetles can find an entry point, they gather by the thousands in wall spaces and window/door frames. Common over-wintering sites include: window and door frames; porches, garages and out buildings, beneath exterior siding, under roof shingles, wall voids, soffits and in attics. Structures in poor repair are especially vulnerable to invasion.
Asian multicolored ladybird beetle releases a fluid that has a foul odor and difficult to wash off. It will also leave a yellow-orange stain that, for all intent and purposes, is permanent. The easiest way to remove them is with a vacuum. If you want to save them for you garden, place a pair of panty hose in the vacuum and secure it with a rubber band.
Once you’ve filled your stocking with beetles, take it outside. When it warms up in the spring, you can release them. You can also try to sweep them up. But this method will disturb them and may crush a few.
To stop future incursions, do a little pest-proofing. Seal up every nook and cranny with caulking. Adjust or install tight fitting door sweeps or thresholds at the bottom of exterior doors. Any gaps greater than four millimeters will allow halloween beetles to re-enter your home. Repair damaged window screens. Seal up utility openings where pipes and wires enter walls or foundation.
I don’t recommend using pesticides against these creatures. Bug sprays will have limited effect against hibernating beetles. Their metabolism has slowed too much. You’re better off saving them for your garden next spring.
Tim Lockley, a specialist in entomology, is retired from a 30-year career as a research scientist for the U.S. Department of Agriculture. For answers to individual questions, please send a stamped, self-addressed envelope to Tim Lockley, c/o Sun Herald, P.O. Box 4567, Biloxi MS 39535.