The warehouse beetle, Trogoderma variabile, is one of several species of beetle in the genus Trogoderma that are considered pests of stored products. It is the most common Trogoderma pest in homes. The warehouse beetle is oblong to oval, 1/8 to 3/16 inch long, with a dark and light mottled pattern on their wing covers. Adult Trogoderma are fairly short-lived and rarely feed on stored products. However, they are considered excellent fliers and can disperse quite easily.
Typical of some other dermestid species (e.g., carpet beetles), larvae are covered with tufts of long hair. In addition, hairs on the last several abdominal segments of the larvae are dark red to cinnamon colored. Larvae are capable of penetrating common packaging materials, boxes, and bags. Severe infestations are often characterized by an abundance of cast larval skins, live larvae of various sizes (ages), and adults all on the same food item. The cast larval skins, cadavers, and debris from Trogoderma infestations can be allergenic.
When food becomes scarce or disappears, Trogoderma larvae may enter a lengthy period of inactivity known as diapause, where insects are completely inactive and do not feed. When larvae break diapause, they can resume infesting food items. This ability to diapause in the absence of food combined with the ability to chew through packaging can make control of Trogoderma beetles difficult.