A Banner Year for Larder Beetles

Larder beetles belong to the carpet beetle family of scavenger insects. The varied carpet beetle is a member of this group and commonly arrives in samples from homes during the spring. However, 2015 has been a banner year for a related species: the larder beetle.

In general, carpet beetle larvae are “hairy” and worm-like. However, a pair of curved horns at the end of the abdomen (Figure 1) set immature larder beetles apart from other species.

Figure 1.  Larder beetle larvae with a pair of curved horns at end of abdomens. (Photo: Lee Townsend, UK)

Figure 1. Larder beetle larvae with a pair of curved horns at end of abdomens. (Photo: Lee Townsend, UK)

Adult larder beetles (Figure 2) have about 1/4-inch long oval, dark brown to black bodies. A light band with 6 more or less prominent dark spots runs across the wing covers.

Figure 2. Larder beetle adult (top and bottom views). (Photo: Lee Townsend, UK)

Figure 2. Larder beetle adult (top and bottom views). (Photo: Lee Townsend, UK)

Larder beetle adults and larvae can feed on a wide variety of animal matter. In nature, they recycle feathers, skins, and carcasses.  Around the kitchen and storage areas, they can feed on fur, hair, hides, feathers, cured meats, stuffed animals, and cheeses.  In some cases, infestations can be traced to grease deposits behind or under stoves or in fume exhausts.  Larder beetles can also develop in dead insects or other animals (boxelder bugs, attic flies, mice, etc.) in wall voids or attics.  Dead rodents, bats, or birds trapped between walls or in chimneys, heating ducts, or crawl spaces, as well as accumulations of dried insects in windows or ceiling light fixtures, can be food sources for these beetles.

Management

  • Discard the food source of larder beetles if it can be found. Then clean the area thoroughly. Vacuum cracks and crevices, and then scrub the area with warm, soapy water to remove attractive grease or odors.
  • If no specific food source for the insects can be found, then the beetles may be coming from wall voids or other places where removal or sanitation is not practical. Often the source will be consumed or become unacceptable for the beetles and the infestation will end.
  • A residual insecticide can be applied after clean-up. Readily available insecticides for homeowner use include liquid sprays in an aerosol can or a trigger pump spray applicator (“ant and roach killer,” “home pest control,” or similarly-named products). Dust insecticides, such as boric acid, are very fine powders that must be evenly spread in a thin layer or injected into voids and insect hiding places to be effective. Follow label directions carefully.

 

By Lee Townsend, Extension Entomologist

 

 

Posted in Household Pests