The drugstore beetle is a common household insect that can infest a variety of stored products. Understanding their flight capabilities, physical appearance, and preferred habitats helps in identifying and managing these small but persistent pests.
Their Flight Capability
Adult drugstore beetles are capable of flight. They possess wings and can fly short distances for dispersal and finding new resources. These beetles are often more active flyers at night and are attracted to light sources. This attraction can lead them to fly into homes through open windows or other entry points, especially in the evening.
Their flight serves several purposes, including spreading to new areas and locating new food sources or suitable locations for laying eggs. While they can fly, their movement is often erratic. Factors like temperature can influence their flight activity, with flight initiating at temperatures above 68°F (20°C). This flight capability contributes to their ability to spread infestations, making it challenging to locate the initial source of an infestation.
Identifying the Drugstore Beetle
Drugstore beetles are small insects, typically measuring between 2.25 to 3.5 millimeters (about 1/10 to 1/8 inch) in length. They have a reddish-brown color and a cylindrical, oval-shaped body. A distinguishing feature is their head, which is bent downward and often not visible from above, giving them a somewhat humpbacked appearance.
Their antennae are another identification marker. Drugstore beetles have antennae that end in a three-segmented club, differentiating them from similar-looking pests like the cigarette beetle, which has serrated or saw-like antennae. Furthermore, their wing covers, known as elytra, have distinct longitudinal rows of pits or fine hairs, giving them a striated or grooved appearance. These features, combined with their small size, help in visually identifying a drugstore beetle.
Where They Live and What They Eat
Drugstore beetles are found worldwide, thriving in warmer climates or heated indoor environments. Within homes, they commonly infest kitchens, pantries, and other areas where dried foods and spices are stored. They are known for their broad and indiscriminate diet, earning them the reputation of eating “anything but cast iron.”
Their food sources include a wide array of items such as grains, flour, bread, cereals, pasta, spices, dried fruits, seeds, coffee beans, and pet food. Beyond food items, drugstore beetles can consume non-food materials like books, leather, wool, hair, and certain pharmaceuticals, which is how they earned their common name.
The adult beetles do not feed significantly, but they lay their eggs on these varied materials, and the larvae then cause damage as they tunnel through and consume the infested products.