The group of similar looking beetle species that belong to the Coccinellidae family are commonly known as “ladybugs,” and while many people are under the impression that all ladybugs found throughout the US are one and the same species, there actually exists more than 6,000 ladybug species worldwide, including 150 in the United States. Native ladybugs are generally well tolerated by humans in the US, as they do not demonstrate pest behaviors, and many people consider them to be alluring and interesting insects. However, this is not the case when it comes to the non-native ladybug species, Harmonia axyridis, which invades homes in large numbers from September through November.
Today, these ladybug pests, which are more commonly known as “Asian lady beetles,” outnumber native ladybugs in the US, and they first became notable as nuisance home-invading insect pests in upstate New York during the fall of 1995. In addition to being a nuisance, Asian lady beetles inflict bites, and perhaps worst of all, they secrete a sticky and odorous substance within homes that leave lasting stains on carpeting, clothing, curtains, and interior and exterior walls.
On Halloween night in 1995, Asian lady beetle swarms pestered young trick-or-treaters in upstate New York, prompting countless calls to local extension offices and pest control companies in the state. At the time, and due to their resemblance to common ladybugs, Asian lady beetle pests were widely considered to be native ladybugs behaving strangely, but today, Asian lady beetle pests are well known to upstate New York homeowners. As many as 10,000 Asian lady beetles can congregate in one single corner within homes, and they also tend to gravitate into inaccessible indoor areas, such as wall voids and beneath flooring. Unfortunately, when these insect pests become stressed or threatened, they secrete blood or “hemolymph,” which is orange, sticky and foul-smelling.
Attempting to remove these pests from walls, curtains, or carpeting will leave these indoor items and surfaces stained with a plethora of orange and smelly stains. Asian lady beetle invasions often persist into November in upstate New York, and according to residents in the area, the pests have destroyed curtains, crawled into beds, invaded dresser drawers where they stained clothes, set off smoke alarms, and a few residents even claimed to have found the bugs crawling beneath the translucent film covering laptop monitors. Residents can help to prevent invasions by installing barrier screens over crawl space and attic vents, installing door sweeps, and sealing cracks and other entry points on the exterior walls of houses.
Have you ever sustained a bite from an Asian lady beetle?