Facts, Identification & Control
Dermestes lardarius (L.)
The larder beetle is a large oval insect. The adult is about 7 to 9 mm long. It is usually black with a yellow band across the wing covers. There are several dark spots in the yellow area.
Behavior, Diet & Habits
The larder beetle may get its name from the fact that it is a pest of cured meat and other stored food products. It is a member of the beetle group called dermestid beetles.
When they invade a home, larder beetles move into dark areas where they can find food. They prefer to feed on dead insects and stored meat or cheese. They will also feed on feathers, skins, horns and dry pet food. They will infest pantries and storerooms where people store pet food. Larder beetles also infest nests of squirrels and rats in wall voids and attics. They can move from these areas into almost any part of a home.
The female beetles lay eggs in the spring and summer. When the eggs hatch, the larvae burrow into the food material. The larvae mature to pupae and then adults in two or three months. When it time for them to change into adults, the larvae leave the food and burrow into a solid material. They make a small chamber and seal themselves inside the chamber so they can change into adults.
Signs of a Larder Beetle Infestation
Infested items can have holes. Upon close examination, the hairy larvae and their shed skins may be seen. Another sign is their thin fecal pellets which can be up to 3 mm long.
Controlling larder beetles requires an inspection and cleaning. The first step is a thorough inspection. The object of the inspection is to find the source of the infestation and remove anything that is infested. The kitchen cabinets and pantry are good starting places. Remove everything and examine every package. Discard anything that is infested. Vacuum the empty shelves. Try to store new food products in sealed glass or plastic containers. Look in the garage and storerooms for infested pet food or animal feed.
It can be challenging to find the source of a larder beetle infestation. They can infest furs and animal trophies. They can also infest bird and animal nests, so sometimes the inspection includes the attic and crawlspace.
The inspection and cleaning are critical parts in solving most larder beetle infestations. Insecticide application is the final step. Insecticide is used for eliminating any beetles that are changing into adults. The insecticide will be effective if it is applied into the cracks and crevices at the back of the shelves and behind the baseboard. To avoid misapplication, it is usually preferable to call the local pest control professional.