Thom Smith: Colder weather means insect invasion

'Tis the season of home insect invasions!

Not all insects die with onset of cold winter, many winter over in leaves, under bark or elsewhere outside. The wooly bear caterpillar, or woolly worm, is the caterpillar we look to to predict the coming winter. The story is the narrower the rust brown stripe in the center of the body, the harsher the winter will be. According to one I saw recently, it will be the worse winter since the glaciers began forming. Of course, this isn't true!

It often spends the winter under leaves or other plant debris and may freeze solid. In the spring, this insect thaws and life resumes changing into a moth. There are others too, but they don't ever seem to be a problem.

On the other hand, there are insects that are a problem:


The box elder bug is apparently the star home invader in many towns and cities in the Northeast (and elsewhere) this season. It is easily identified by the orange and red marks on its black body. They are about 1/2-inch long and have three stripes behind the head. This species is a true bug and, in some places, is called a maple bug. They feed on low vegetation on the ground during early spring and summer. Around mid-July, they move to female box elder trees to feed on the seeds. By late summer, they leave trees and start searching for over-wintering sites, often warm homes and other buildings. They seek outbuildings with sunny exposure and this is most likely where they are first seen, often by the hundreds and without exaggerating in some instances, by the thousands. They gather on the sunny side of your home. It appears that infestations are more common after a warm spring followed by a hot, dry summer. Even unheated buildings with siding may be invaded, as they find warmth beneath siding and in insulation, and with the coming spring, may lay eggs.

We can continue, but before running out of space, should say a few words about how to control them. Once inside the house, the best way to remove them is by vacuuming them. This method will avoid crushing, that almost always ruptures scent glands and rupturing the dye sacks that contain a defensive red enzyme that stains walls, drapes and woodwork. I learned this with a fly swatter some years ago.


Stink bugs, a gift from Asia, are widespread in the United States. Regardless of the species, stink bugs, as their name suggests, stink. Crush one outside and find out for yourself just how horrible their odor is. Like the box elder bugs, they enjoy the warmth of the sunny side of houses. They may never show themselves inside the home though, content with being within walls. When large numbers invade homes, their normal activity may leave a foul odor, and is very difficult to eliminate.


When hordes of ladybugs show up on the sunny side of your home and somehow find a way inside by the hundreds, they are not the "cute" little ladybugs of nursery rhymes that we might have played with as kids. They are the multi-colored Asian ladybug (actually a beetle), sometimes called the many-named ladybird. Some call it the pumpkin ladybug, Halloween or harlequin ladybug (ladybird, ladybeetle) that was introduced in 1978 and 1981, but apparently never appeared to prove very helpful and disappeared. Years later, in 1993, the first over-wintering beetles were seen, and began proliferating in places like New England. And, apparently, those we see today may not have come from those first introductions. Instead, they are thought to have been accidentally introduced in New Orleans from an Asian freighter. I recall writing about many thousands of these pests showing up in sheds, garages, attics and even inside the home. I began finding them in our home tucked into warm places behind drapes by the dozens, thankful that there were not far more. Again, the vacuum was the easy way to remove them. One difference from our native lady bird beetles (a more proper common name) is these sometimes bite. It is difficult to describe them as they are multi-colored. When seen together, some may have a couple black spots on a yellow background, while others may have as many as 10 spots (or even more) on orange or red backgrounds, or any combination. Like the name suggests, they are multi-colored. I have seen a few with only two spots.

The first time I saw them was while hiking, I believe on Mount Tom, and finding literally thousands on the south side of the house there.

Thom Smith welcomes readers' questions and comments. Email him at or write him care of The Berkshire Eagle, 75 S. Church St., Pittsfield, MA 01201.


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