The lucky little lady bug is not so lucky anymore and its numbers certainly are not little. The multicolored, spotted, diminutive, flying creatures that seem to be overrunning our homes is not the same cute little lady bug of childhood memories.
It is somewhat controversial about when the tiny tormenting torpedoes that are invading our environment today were first introduced in this country.
Although the Asian lady beetle (Harmonia axyridis) was imported and released in the United States years earlier, the first evidence that they'd survived and populous numbers were noticed was not until 1988 in Louisiana. They started becoming a problem in the midwest around 1994.
According to Dick Crum, well known horticulturist and former extension educator in Marion County, the Asian beetles were brought in as an effective, natural control of crop damaging plant pests such as aphids, scale and other soft-bodied arthropods. The most apparent identifying character of the Asian lady beetle is the black 'M' inscribed on their thorax, just above the wing covers.
One reason for their large numbers is probably that their introduction into a new habitat in the United States freed them from some natural population checks and balances that occur within their native Asian range.
It's likely that time will take care of much of their over population as natural controls will probably catch up to the lady beetles and curtail their booming population.
According to "Household & Public Health" from the Purdue University Cooperative Extension Service, the Asian lady beetles have become a serious nuisance pest inside buildings but they are not a health or property damage threat. They do not directly damage anything in the home, do not infest stored food and do not destroy household furnishings. They do not lay their eggs in homes.
The only known possible health threat might be to allergy and asthma sufferers if accumulated dead beetles are not cleaned up and particles of dried and crushed beetle bodies become airborne.
But their very numbers in the fall have become a major irritant to many homeowners.
They fly into living spaces, drop from light fixtures and literally bump into people.
Also, according to Crum, if agitated or squashed, the beetles may exhibit a defensive reaction known as "reflex bleeding," in which a yellow fluid with an unpleasant odor is released from leg joints. This reaction generally prevents predators, such as birds and wasps, from eating them. But in the home, the odor is very unpleasant and the fluid may stain walls and fabrics.
Whether or not they bite is also a controversial issue. "Household & Public Health" says that "some homeowners have complained that on very warm days, especially when a person is perspiring, the beetles pinch when they land on bare skin. Why this phenomenon occurs is not completely understood but the pinching does not break the skin therefore disease transmission cannot occur."
However, Parke County Extension Educator Mark Spelbring, says he has read that the beetles take a bite of different substances, including human skin, to determine, by trial and error, what is a viable food source. Human tissue is not food for Asian beetles. Their natural food source, the soft-bodied arthropods, diminishes when crops are harvested in the fall.
Congregation usually is initiated by the first cold weather snap in October that is followed by warm temperatures. During this congregating activity, hundreds of thousands of beetles may appear around homes.
The beetles eventually find their way into homes through small cracks or openings in window sills, door jams or foundations. They will remain there for several months in a hibernation-like mode until the first warm days of late winter or early spring, when they seem to come to life again and begin crawling about. They usually depart in the spring in search of food.
Asian lady beetles are attracted to:
- Abrupt longitudinal color contrasts on buildings such as black shutters on a white house.
- Lighter colors, whites, grays, yellows.
- Buildings close to trees or woods.
- Highly illuminated or southwest-facing sides.
- Clusters of like lady beetles.
- Caulking exterior cracks and crevices before the beetles seek overwintering sites.
- Sweeping or vacuuming the insects from living area. Be sure to empty the vacuum bag afterwards as beetles can get out of the bag.
- Chemicals can be used as either a perimeter treatment outside or sprays or 'fogs' indoors. The key is to apply the chemicals to the outside of the home in October while the beetles begin to congregate but before they enter the home. Seeking professional pest control advice is recommended.
Garlinda Mathews, from Reelsville, gives no guarantees but she found a solution that worked for her.
"All-purpose household cleaner," Mathews said. "Once a month, starting about April or May, I spray around the windows and doors outside. And inside I wipe down the window sills. It doesn't matter what brand. I've used all different kinds.
"It worked for me. It doesn't kill them. But they don't like it. I guess they just go to the neighbors."