Adult larder beetles (Dermestes lardarius) are 1⁄3 inch long black beetles with a broad, pale tan, black spotted band across the front portion of the wing covers. Larder beetle larvae are reddish brown and densely covered with short and long hairs, and have two curved spines on the top of the tail end. Both adults and larvae feed on high protein food sources including cured and spoiled meats, dried fish, high protein pet food, dead insects such as cluster flies and boxelder bugs, furs, feathers, leather, cheeses, dead rodents and birds in chimneys or wall partitions, and even rat or mouse poison baits. Larder beetles are a type of carpet beetle, but they only attack woolens that have been soiled with blood, fish oils, or other high protein stains. Close relatives of the larder beetle are used to clean the flesh from skeletons used in museums.
University of Wisconsin, Insect Diagnostic LabRead Full Document