Purdue News

October 27, 2000 Halloween invasion of lady beetles an annual nuisance WEST LAFAYETTE, Ind. – Huge numbers of Asian lady beetles can make the insect's annual late October invasion a scary event in Indiana and across the entire eastern portion of the country, says a Purdue University entomologist. "We have received many reports this year of them biting, pinching and certainly smelling bad," said Timothy Gibb, an integrated pest management Extension specialist. While lady beetles are not normally considered aggressive, he said the insects may pinch if the weather is hot enough, and if they are in large enough numbers. Unlike native lady beetles, the Asian lady beetle makes itself a nuisance by congregating inside people's homes to spend the winter. This time of year, they are clustering on the sides of buildings, trying to find small cracks or crevices through which to work their way in. The Asian lady beetle is not always easy to identify because it varies in color from yellow to red and sometimes has dark spots. Gibb said one of the defensive tactics of these beetles is to emit a foul-smelling substance when disturbed. "Sometimes hundreds or even thousands of these beetles will invade a home, making them an obnoxious nuisance," he said. Gibb said the easiest way to dispose of beetles inside the home is to vacuum them up. "A long extension will suck them from ceilings and light fixtures," he said. "I have found that most die after being sucked through the vacuum. "We don't recommend aerosol-type foggers inside the home," Gibb said. "The effect of these treatments is negligible because the foggers only reach exposed surfaces, where the beetles can just as easily be swept up." As a preventive measure, caulking exterior cracks and sealing around windows, doors and pipes may help keep these unwanted winter visitors out of the home. Pesticides also can be applied to the exterior of the building to keep beetles from entering. The Asian lady beetle was introduced into this country as a way to control aphids. However, the natural diseases, parasites and predators that keep it in check in foreign countries were not imported as well. It may be several years before natural enemies of the Asian lady beetle have time to build up, Gibb said. At that time, the Asian lady beetle numbers should subside. Source: Timothy Gibb, (765) 494-4570; tim_gibb@entm.purdue.edu Writer: Beth Forbes, (765) 494-2722; bforbes@aes.purdue.edu Purdue News Service: (765) 494-2096; purduenews@purdue.edu To the Purdue News and Photos Page