Four Fall Invaders to Prepare for

As insects prepare for winter, they must try and survive the changes in temperature that are coming. Some may migrate to warmer places, some can survive being frozen, but a few see your home as a toasty timeshare they can borrow for the winter!

The Invaders

Boxelder bugs

These true bugs spend most of the summer feeding on boxelder and maple trees in the landscape. As adults, they are about ½ inch long, are black, and have red lines on their sides and back (Figure 1). Their nymphs (the immature form of their lifecycle) are black with a bright red abdomen that has a yellow spot on the back. They like to warm themselves on the south and west facing sides of structures.

Brown marmorated stink bug

A relatively new insect pest in Kentucky, the brown marmorated stink bug is a stinky invader and a pest of numerous crops. Some may deal with them on their corn, peppers, apples, or other homegrown produce in the summer. As adults they are ½ inch long with a yellow, bronze coloration and numerous small white dots (Figure 2). The tips and sides of their abdomen have small white triangles and the antennae have white bands.

Figure 1: Boxelder bugs are very common home invaders; if screens are properly secured then they should not be able to gain access to the house. (Photo: Jim Kalisch, University of Nebraska-Lincoln Department of Entomology)

Figure 2: Brown marmorated stink bugs are invasive pests that attack crops in summer and invade homes in fall. Thousands can descend upon a house, creating a difficult situation. (Photo: Jim Kalisch, University of Nebraska-Lincoln Department of Entomology

Multicolored Asian lady beetle

Also known as the Halloween beetle or the Asian ladybug, this is an introduced species. It does help with pest control during the summer by eating aphids and other plant feeding insects. They can be tricky to identify because they come in several shades of orange and can have numerous spots, or no spots at all (Figure 3). Usually, you can look at the top of the thorax and find a letter “M,” which of course stands for multicolored Asian lady beetle. They are fall home pests and also can be problematic for vineyards where they occasionally taint wine.

Western conifer seed bug

This true bug feeds on the sap of developing cones on conifer trees. They are ¾ inch long and dark brown with yellow squares along the edge of their abdomen. Part of their back legs are flattened, which gives them a boat oar appearance (Figure 4).

Figure 3: Adult multicolored Asian lady beetles can be light to dark orange, can have many spots or no spots at all, but usually all have an “M” on the thorax. (Photo: Jim Kalisch, University of Nebraska-Lincoln Department of Entomology)

Figure 4: Western conifer seed bugs have impressive looking “calves” on their back legs, which help to separate them from similar looking pests. (Photo: Jim Kalisch, University of Nebraska-Lincoln Department of Entomology)

Managing the Invaders

These kinds of pests are hard to deal with because they are not looking for food, mates, or water. They merely want to be somewhere warm. Since you are unlikely to turn off your heat for the winter, you can’t really remove their temptation. Therefore, the best strategy is a good defense.

Ensure that the perimeter of your home is well secured. Check caulking around doors and windows, make sure that screens fit tightly and there are no large holes in the screening. Pipes and chimneys should also be checked for access points.

Insecticide barrier treatments can stop some invaders, but if you put the product out too early the residues will fade before the invasion; too late and they are already inside. It might be best to hire a professional to try and use a pyrethroid type product on the exterior of your home.

If you find some of these insects inside, the best course of action is to simply vacuum them up and dispose of them outside. Avoid using insecticides indoors, in particular the “bug bombs.” If you find a large group of these insects, you can spray them with soapy water to kill them before removal.


By Jonathan L. Larson, Extension Entomologist



Posted in Household Pests
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