Asian Lady Beetle: Q & A
By Chris Williams on October 6, 2010.
Q. In the last few years, homes in our neighborhood have been invaded by what are called Asian lady beetles. I thought lady beetles were outside bugs! What can we do to keep them out.
A. Most lady beetles (ladybugs) are beneficial since they live outdoors and feed on plant pests. But the Asian lady beetle, which has only been in this country for a few years, can be a serious pest. It can swarm into buildings from September through November looking for a place to spend the winter, and hundreds or thousands may find their way into your attic and wall voids, and then wander into living areas during warm winter days.
These beetles secrete a yellowish fluid when disturbed, and this fluid can stain walls, furniture, and other surfaces. They also can cause allergic reactions in some people.
Once they are inside, they are tough to deal with. Aggressive vacuuming is probably your best tool. But you’re much better off keeping them out in the first place. Caulk and seal openings 1/8-inch wide and larger from ground level to the roof line where beetles can enter such as:
- Around windows and doors
- Gaps and cracks where different materials meet, such as where siding fits over brick or block
- Gaps around the fascia board and soffits at the roof line
- Openings around pipes, spigots, cable lines, etc.
- Use sweeps and thresholds to eliminate gaps under doors, including garage doors
- Repair damaged screens and windows
Be thorough because lots of Asian lady beetles can enter through just a few openings.
We can help, too, by applying a special, long-lasting barrier treatment around your home that will keep the beetles from entering. But for the treatment to be effective, be sure to call us before the weather gets cold.