On the Way Out

Several insects that overwinter in protected places, including houses and other buildings, are on their way out now. There is not a lot to do at this point other than clean up any accessible accumulations of dead individuals that could contribute to a carpet beetle problem. Here are some of the common problem species.

Common Home Invaders

Face Fly

The face fly (Figure 1) breeds only in fresh cow manure. Adults closely resemble house flies so this species occurs in rural areas near pastured cattle.

Multicolored Asian Lady Beetle

The multicolored Asian lady beetle (Figure 2) occurs in both rural and urban areas. These insects tend to be most common near wooded areas. Besides being a nuisance, the beetles emit an acrid odor and can stain surfaces with their yellowish secretions when disturbed. The secretions are volatile compounds used in defense against bird and other vertebrate predators.

Figure 1. Face flies. (Photo: Lee Townsend, UK)

Figure 2. Multicolored Asian lady beetles have orange wing covers with variable patterns of black spots. (Photo: Lee Townsend, UK)

Boxelder Bugs

Adult and immature boxelder bugs (Figures 3 & 4) are common insects that feed on sap from leaves, twigs, and seeds of boxelders, as well other members of the maple family. Large numbers of these red and black insects can be seen on tree trunks, on branches, or sunning themselves on the south or west sides of buildings in spring. These harmless accidental invaders may be a temporary nuisance as they move into and out of sheltered overwintering sites.

Figure 3. Boxelder bug adult (Photo: Lee Townsend, UK)

Figure 4. Boxelder bug nymph with wing pads on shoulders and orange spot in middle of back. (Photo: Lee Townsend, UK)

Brown Marorated Stink Bug

The brown marmorated stink bug (Figure 5) has become a major nuisance pest to homeowners in some parts of the state. Large numbers aggregate in homes, and when disturbed, they will produce a foul odor. Fortunately, they pose no threat to human or animal health inside the home.

Figure 5. Adult brown marmorated stink bug. (Photo: Lee Townsend, UK)


Fall invaders are leaving their shelters to resume their lives. The main options for dealing with them are preventive. Two useful things at this point are:

1) Locate and remove any accumulations of dead insects that can be found. The attic is a good place to check. Dead insects are sources of problems with carpet beetles and other scavengers that can subsequently attack stored products and garments made of natural products (e. g. silk, cotton, wool).

2) Look for entryways that can be screened or sealed to prevent pest entry in fall.


By Lee Townsend, Extension Entomologist



Posted in Household Pests