Now is the time we typically encounter larder beetle adults and larvae in the house. Larder beetles are common and widespread but often go undetected except during the springtime "wandering around" period.
The larder beetle got it's common name before refrigeration was widespread and the beetles attacked dried, cured meats stored at room temperature in the larder (now known as the pantry). Today, larder beetles are rarely a pest in stored foods (dried fish, pet food, cheese, etc.) but rather infest other items of high protein content such as dead animals, fur, hair, hides and feathers. The most common source of larder beetles is probably dead boxelder bugs, attic flies or mice in the innerwall spaces of the house.
The larder beetle adult is slightly longer than 1/4th inch. It is roundly oval and dark brown to black with a characteristic light colored band running across the body. This light band contains 6 more or less prominent dark spots. Larder beetle larvae are up to 1/2 inch long. They are tapered in shape and covered with sparse, stiff hair. There are 2 upward curved spines on the posterior end.
Elimination of larder beetles would require finding and eliminating the sources of the larvae. This may be feasible with stored product infestations but not with house wall infestations. When a larder beetle infestation occurs in a cupboard or storage closet, all food items should be removed and the infested products discarded. The shelves should be thoroughly vacuum cleaned and the materials inspected before returning them to the cupboards.
If the infestation is more general in nature and specific source(s) of the insects cannot be located, a general control process may be helpful. Thoroughly vacuum clean cracks and crevices in the areas where larder beetles are found. A residual insecticide treatment can be applied to these areas following cleaning. Readily available insecticides for homeowner use include the "ant and roach killers" and the "home pest control" products found in grocery and hardware stores and garden centers.
This article originally appeared in the April 1, 1992 issue, p. 45.