Victim of the Larder Beetle

Imagine the scenario... You go to your kitchen cupboard to get some dry food for your pet. As you reach for it, you notice a couple of small, dark, hairy-looking "worms" on the bag. When you look closer, you see a couple more on the shelf, away from the bag. There are even several small holes in the wooden molding along the edge of the shelf.

In this case, you are probably the victim of larder beetles.

Larder beetles are cosmopolitan stored product pests which infest high-protein, animal materials, such as meats, cheese, feathers, or hair. They often infest dried pet foods, fish, or nearly any product of animal origin. They very rarely eat materials of plant origin, and may invade museum specimens, dead insects, or accumulated lint and hair in wall voids.

Adult larder beetles are oval insects, which grow to around ¼ inch in length. They have a pale yellow band across their back and both the front one-third and the back one-third of their body is dark brown to black. They can also be recognised by the 6 to 8 dark spots on the yellow cross-band. Larvae of the larder beetle are ¼ - ½ inch long, dark brown and covered by dark brown hairs. These hairs often appear to be arranged in bands across their body, alternating with lighter inter-segmental bands.

Adult female larder beetles lay 100-800 eggs on suitable larval food, or in cracks near where such materials are stored or have accumulated. Usually, male larvae molt five times and female larvae molt six times before they crawl away from the larval food to find a suitable site to pupate. In temperate climates, there is only one generation a year, but as many as six generations a year have been reported under optimal conditions, with the beetles overwintering in crevices in tree bark, or similar sheltered sites.

Most damage is done by larval feeding. When larvae are mature, they may crawl several feet away from the material they were feeding in, and drill a hole up to ½ inch deep in soft wood. They have even been know to penetrate thin sheets of soft metals such as copper, aluminum or lead and are well adept to penetrate thin plastic. A plastic bag of at least 3mm may keep adults from detecting its contents, even if those were items they would normally infest.

The key to controlling larder beetles is to find all their breeding sites and eliminate them. Start by examining dry pet foods and pantry areas nearest to where you first discovered the beetles, but be sure to consider furs, animal hides, hunting trophies (often mounted and hung on a wall), and decorations or wall hangings made from or containing skins, hair, or leather. Also consider past problems with flies, ladybirds, rodents or birds.

Your inspection should be followed by good sanitation (removal of all infested materials found), and application of a properly-labelled pesticide when needed.

Article provided by SDA Pest Control