By PAUL HETZLER

What’s oval-shaped, mostly orange, and is a common sight around Halloween time? Everyone knows the answer to that: Harmonia axyridis, obviously.

Better known as the multicolored Asian lady beetle or lady bug, this insect, while beneficial to gardens, is no treat when it masses by the hundreds on and in homes in the fall.

First brought to the U.S. in 1916 to control pests on pecan trees and other crops, the lady bug, darling of small children everywhere, didn’t turn into an ogre until the mid-1990s. Actually, there’s evidence to suggest that the current population is a new strain accidentally released at the Port of New Orleans around 1993. Whatever their origin, they’re back in season now along with corn shocks and jack-o’-lanterns.

Lady beetles don’t carry disease, damage structures, suck blood or sting, and they eat harmful garden pests. However, they stain surfaces, give off a foul odor when disturbed and will even pinch one’s skin on occasion. It’s their sheer numbers, though, swarming an exterior wall, huddling in a corner of the garage or coating the inside of a picture window, which unnerve and irritate so many people.

Managing lady beetles, it turns out, will cut your heating bill. They’re looking for someplace warm to spend the winter and if a draft can get in, so can they. Caulk around windows, vents and where cable or other utilities come through the wall, and seal between the foundation and sill. Ensure that door sweeps/ thresholds are tight and check for cracked seals around garage doors. Install screens on attic vents and inspect all window screens.

If the beetles are already indoors, don’t swat or crush them or they’ll release a smelly, staining yellow defense fluid. For a variety of reasons including the lady bugs’ habit of seeking inaccessible areas, indoor pesticide use is strongly discouraged. Rather, use a broom and dustpan, vacuum cleaner or shop-vac. Try using a knee-high nylon stocking inserted into the hose and secured with a rubber band as a reusable “mini-bag.” Just remember to empty it as soon as the vacuum is turned off. You can also make a black light trap; instructions can be found at: http://www.ars.usda.gov/is/pr/2001/010130.htm

This fall, researchers will be decorating giant pumpkins as Asian lady beetles in hopes of frightening the actual lady bugs away. If you see a 300-pound lady bug on Halloween, please call Cooperative Extension at 379-9192. Definitely don’t swat it.

Paul Hetzler is a forester and a horticulture and natural resources educator for Cornell Cooperative Extension of St. Lawrence County.