Larder beetle
Dermestes lardarius Linnaeus

Order: Coleoptera
Family: Dermestidae
Acronym: DLA

Ecology

The larder beetle is found worldwide. It is widely distributed in Canada where it is a common minor pest in households. It feeds on the remains of other insects and products of animal origin such as hides, furs, skins, feathers, processed and dried meats, cheese, wool, and dried fish. It also feeds on vegetable products with high protein. It is frequently found in grain storage areas where it feeds on the remains of other insects.

Damage

The larder beetle is a minor pest in grain storage. Both the adult and larva feed on materials of animal origin. They also feed in spoiled grain residues, where they are likely feeding on insect remains. The larva burrows into the commodity to feed leaving holes. It also bores into solid materials such as wood, mortar or soft metal, to pupate, which can damage storage buildings or containers. A sign of infestation is contamination with cast skins and the remains of the adult beetles.

Life history

The adult is long, oval and covered in dense hairs. It is slightly flattened and has clubbed antennae. It is 7 to 9 mm long. It is dark brown to black with a wavy pale buff band across the elytra. There are three black spots on each elytron. Its underside is covered in hair. Adult longevity is 60-90 days. Adults can fly.

Ideal breeding conditions are temperatures between 15°C and 30°C and a relative humidity of 40%. The female lays eggs randomly on the food source. If the female has access to water, she can increase the number of eggs she lays.

The larva is yellow-brown and cylindrical. It is long and can become up to 20 mm long when it is full grown. It is covered with dense hairs. It can be distinguished from other Dermestid beetles by the appearance of two small horn-like structures at the tip of the abdomen. The larva will seek a pupation site and then pupate in the last larval skin.

Ideal conditions for development are a temperature between 18°C and 20°C and a relative humidity of 80%. In these conditions, development can take 45 days. The larva can slow its development if ideal conditions are not present.

Control

Controlling insect infestations

Images

Drawing of an adult larder beetle.

Natasha Wright, Florida Department of Agriculture and Consumer Services, Bugwood.org
Adult larder beetle

Natasha Wright, Florida Department of Agriculture and Consumer Services, Bugwood.org
Adult larder beetle - side view