by Steven Jakobi, Master Gardener Volunteer, Cornell Cooperative Extension of Allegany County
Autumn is a time for unwanted guests in the house. These insects are like squatters, moving in for the winter and looking for a place to ride out the cold months.
In my house, we have to deal with cluster flies, Asian lady beetles and western conifer seed bugs. (Western conifer seed bugs are often confused with the marmorated stink bug.) Other folks I know also have occasional infestations by boxelder bugs.
All of these insects can be a nuisance if their numbers are big enough. Their populations may fluctuate from year to year, depending on a number of environmental and population control factors, but in some years there may be hundreds or even thousands attempting to enter homes.
None of these come to eat or reproduce. They are simply searching for a suitable place to bide their time until the warmer months of next spring.
Cluster fly
Of the insects I listed above, the most loathed species is the cluster fly.
Slightly larger than house flies, they spend the summer months eating flowers and fruit. They also parasitize earthworms during their larval development.
In autumn, they enter homes through cracks or crevices and set up shop in any dark part of the house. These hiding places may be in walls, dark ceiling corners, baseboards or even behind curtains.
If they are numerous enough, they may buzz around the house and occasionally fall into food, clothing, bedding or even people’s hair. They can be quite a disgusting nuisance.
Unlike the house fly, cluster flies do not eat or reproduce in the home and they don’t carry disease-causing germs.
The best remedy is to keep them out in the first place by sealing any openings around doors or windows and caulking tiny crevices. However, this is easier said than done, especially in older dwellings. (A large portion of my home was built in the 1840s.)
Once cluster flies are inside the house, the vacuum cleaner is the home owner’s best friend, although occasionally a professional exterminator’s equipment and chemicals are needed to get rid of these flies. The use of over-the-counter insecticides isn’t recommended.
Asian lady beetles
Multicolored Asian lady beetles were brought to North America from Japan as biocontrol agents of aphids and scale insects in southern forests and fruit orchards. Another group of these beetles was accidentally introduced in shipping containers in the port of New Orleans, and they have been spreading throughout the eastern part of the United States. In New York, they were first recorded in Chemung County in 1994.
Often mistaken for the common ladybug, this species invades homes in October or November and can congregate by the hundreds in ceiling corners, porches or other structures.
Beetles may range in color from pale yellow to dull red, and may or may not have numerous black spots on their bodies.
Like the cluster flies, the lady beetles do not eat or reproduce during the winter months. Many die and litter carpets, floors or tops of cabinets, but the majority simply leave the home when the weather turns warm.
Control measures are pretty much the same as for the cluster fly: exclusion and the vacuum cleaner. The use of insecticides is not recommended.
Western conifer seed bug
For the past three or four years, I have had another group of unwanted guests: the western conifer seed bug.
These insects are often misidentified as “stink bugs.” To be sure, they do produce a strong odor when handled improperly, but they are not related to the marmorated stink bug.
A western North American native, the conifer seed bug has spread eastward and was first recorded in New York State in 1992.
During the summer, they eat the flowers and seeds of pines, spruces, firs and hemlocks.
In the fall, they enter dwellings, but they neither bite nor sting, nor do they cause any damage.
Because of the smell these beetles can give off when injured, some people prefer to handle them with paper towels or disposable gloves.
Adults are about 3/4 inch long, slender with brown stripes and a darker abdomen. They have characteristic bumpy enlargements on their hind legs, which easily distinguishes them from the shorter and wider marmorated stink bug.
I don’t mind these beetles too much in the house, although they occasionally startle one of us in the bathroom or in the kitchen.
For folks who do not care to have them at all in the house, exclusion is once again the best practice.
Boxelder bugs
The boxelder bug is a handsome red-and-black insect that is frequently encountered in areas where boxelder trees (a kind of maple) are common.
For folks who do not care to have them at all in the house, exclusion is once again the best practice.
Exclusion means keeping the pests out of your house; excluding them. Thanks for asking for clarification.
What does Steven Jakobi mean by exclusion?