Most people, even those who don't care much for insects, are at least casual fans of ladybugs. After all, ladybugs are known for their pest-eating habits, and it's difficult to resist their charming, "cute" appearance.
However, the multicolored Asian ladybug (or ladybeetle), can push its welcome too far and may need to be controlled as a result. Below is more information about this species and what can be done to keep this diminutive predator from driving you crazy.
Identifying the Species
The multicolored Asian ladybug is a large species (Harmonia axyridis) of ladybugs that can measure about a fourth of an inch in length. They draw their name from their varied shell appearance; some members of the species are bright orange, while others may be a pale shade of yellow. Some have dots, but many don't.
The one trait that all multicolored Asian ladybugs have in common is the appearance of a black, M-shaped mark immediately behind the heads of adults. This positively identifies the multicolored Asian ladybug and distinguishes it from other species.
Breeding and Behavior
The multicolored Asian ladybug is hatched from eggs laid on leaves close to prey food sources. Once hatched, the larvae immediately began devouring prey insects, which include plant-killing aphids and scale bugs. Even after the larvae mature into full-blown adults, multicolored Asian ladybugs continue to eat these pests.
As adults, multicolored Asian ladybugs tend to congregate in trees, where they will mate and produce multiple generations per year. Though not as short-lived as some insects, the ladybugs will typically die by their third year of adulthood.
Interactions with People
The multicolored Asian ladybug is not native to the United States and was introduced as a natural means of controlling aphid populations. That means they are technically an invasive, though largely beneficial, species. However, not all encounters are favorable for either the ladybugs or humans.
As an example, multicolored Asian ladybugs have multiple defenses that can prove annoying to people. One such defense is the ability of ladybugs to emit a foul-smelling, stain-causing fluid when threatened.
Another unpleasant aspect of multicolored Asian ladybugs is their bite. While they don't carry disease nor are they venomous, the bite of the multicolored Asian ladybug is painful to some individuals and can break the skin. Some people react negatively to the bite by displaying an allergic response.
However, the most frustrating problem caused by multicolored Asian ladybugs is their swarming behavior. During the first cool nights of autumn, the ladybugs will seek shelter from the long, cold winter months by finding a location to hibernate.
Unfortunately, human habitations are the first place often found by multicolored Asian ladybugs, and this can result in the appearance of hundreds of bugs inside homes. Many will die inside houses, thus adding to the mess and confusion; for those that don't, expect to see them crowding around windows on sunny, warmer days in late winter.
Controlling Bug Populations
If you are experiencing an outbreak of multicolored Asian ladybugs, then there are several things you can do to help keep them under control. Here are a few suggestions:
Vacuum swarming bugs—Insert a nylon stocking into a vacuum cleaner hose, then fasten it in place with a rubber band. Turn on the vacuum and suck up the ladybugs; periodically empty the ladybugs out of the stocking and release them into the wild.
Seal possible entrances—It's a good practice to seal your home from insect intrusion, including multicolored Asian ladybugs, so use silicone caulk and expanding foam to close possible entrances. Look for open areas around cables, window frames, door sweeps and pipes and seal them tight.
Spray insecticides—Multicolored Asian ladybugs can be controlled using a variety of insecticides, so it you aren't able to keep them at bay using natural methods, a chemical barrier can work well. Spray the exterior of your home and swarming insects will die before they have a chance to enter. Just be cautious to read the directions carefully and heed all warnings about pesticide use.
If you have a problem with multicolored Asian ladybugs or any other insects, then you should consider contacting a residential pest management service. They can provide you with help in eliminating pests from your home and keeping your spaces free of bugs.