Invasion Of The Lady Beetle

Throughout the country recently there have been many reports of lady beetles invading homes and businesses, prompting thousands of calls to PCOs. Here’s what you should know about these spotted creatures. Virtually all of the 350 species of lady beetles in the United States are beneficial to the environment and have few negative qualities. They feed on harmful insects but can turn into a nuisance quickly by invading homes.

"It’s not unusual to find one or two ladybugs in a house, but many of our field offices are receiving calls from homeowners who have found hundreds in their houses at one time," said Stoy Hedges, manager of technical services for Terminix International, Memphis, Tenn.

"The ladybugs’ food source — aphids and mealybugs found on trees and shrubs — has been plentiful this year providing them with all the food they needed to thrive and multiply," he said. "Now, there are tens of thousands of ladybugs looking for winter homes."

The ladybugs’ eggs are laid in single or multiple groups of 12 on plants infested with aphids. The larvae are flattened and spindle-shaped, with warts or spines on the dorsal (back) side. They undergo four molts and are brightly colored with blue, black and orange. The pupae, which do not form cocoons, are attached to leaves by the tip of their abdomens.

The warmer southern and western walls of a house attract ladybugs and other insects, providing entry into the house through any cracks or holes that may be present. The best method for controlling ladybugs, Hedges said, is to prevent them from entering the house in the first place.

According to the National Pest Control Association, ladybugs may enter homes around the time of the first frost of the season. They can enter structures through any crack, crevice, open window or hole. They don’t cause a huge problem for customers, except for their presence. "They will become active when it gets warm again and try to find their way back outside, where they continue their very helpful work of eating other insects, especially several kinds of major plant pests," the association says.

The reason ladybugs seek the warmth of indoors is because they are looking for someplace warm to stay throughout the cold months. "Ladybugs and a host of other overwintering insects area attracted to the warm sides (south and west exposures) of structures," said Dr. Richard Kramer, president of Innovative Pest Management. "They are looking for places to get into the wall and other protected areas where they can spend the winter.

A few preventive treatments for lady beetles do exist. "The best thing to do is make sure that all cracks and crevices around pipes, wires, windows, doors, etc., are caulked tight to prevent entry," Kramer said. "The exterior of the house can be treated with a microencapsulated insecticide and this will kill many of the bugs landing on the surface. Treating around potential points of entry will also help."

But what if the insects are already inside for the winter and it’s too late to prevent them from coming in? "If they start getting inside now or later during the winter — use a vacuum to remove them," Kramer said. "Try to avoid crushing them because they will leave a stain. Also, sealing on the inside will keep many of them from entering the interior of the house."

As far as insecticides, Kramer says spraying inside the structure is not necessary. Also, Kramer says, unfortunately, there are no baits or traps for lady beetles. The best way to prevent lady beetles is to secure the structure so they are unable to enter the following year.