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They're back!

I was eating a bowl of cereal the other day when "she" dropped in from the ceiling and just missed my bowl. I looked up and several of "her" colleagues were crawling around the ceiling's light fixture.

It's that time of year; sunny, warm October days when multi-colored Asian lady beetles go from being a beneficial insect to a pest. In most situations, ladybugs are good for growers and gardeners as they aggressively feed on plant pests, specifically aphids and scale. If left unchecked, aphids can reduce plant growth and yield. Instead of utilizing insecticides, many growers rely on predators, such as lady beetles to manage a pest infestation.

The pest label comes into play when this ladybug starts their home invasion in the fall by congregating on the sides of homes. In some instances, it may only be 30 or 40 beetles while others experience mass gatherings in the thousands. From the exterior, many find their way into the house.

The problem has occurred the past several years as a non-native lady beetle, the multicolored Asian lady beetle, has become established in our area. According to Cornell University, the USDA made several releases throughout the eastern United States in an attempt to introduce this beetle into North America. It took a long time for releases made in Louisiana and Mississippi in 1979 and 1980 to become established and spread, but are now widely disseminated in North America with frequent reports from the south, northeast, and midwest. Although a friend at times, its life cycle and habits has become a nuisance.

In it native homelands, the Asian lady beetle will congregate and overwinter in cracks and crevices on cliff faces. Unfortunately, we don't have a lot of cliff faces in central Pennsylvania so they have chosen the next best thing, your house. The beetles will tend to congregate on the sides of light colored houses that receive afternoon sun. At this time, they are looking to gain access to your house and set up for a nice winter nap.

The multicolored Asian lady beetle only overwinters in a house. It does not feed on building materials or on human food. Unlike mosquitoes, lady beetles do not carry disease organisms. Luckily, these beetles do not reproduce in structures, so no multiplication is occurring.

Disturbed lady beetles will leave a yellow-orange body stain on walls, drapes, and carpets that is difficult to remove (hint: do not crush these beetles as this really disturbs them). Some people have stated that they have been bitten by beetles but they are not aggressive to humans and the occasional nibble will not draw blood.

Options are few with the management of this insect. If these insects are finding a way into your house, you must prevent them entering by finding and sealing all cracks and crevices with a caulking material. Insecticides are labeled for use in the house, but once used you will need to sweep up the dead beetles. I say skip the use of the interior insecticide application and just vacuum up the beetles live.

This annoyance will disappear as soon as we get into some really cold weather. We will be revisited by them in the spring when they wake up from their long sleep in your house.