Knowledgebase
Asked November 06, 2020, 6:08 PM EST
Calhoun County Michigan
Expert Response
Hello,
That is a larder beetle larva, Dermestes
lardarius (Coleoptera: Dermestidae).
Both the larvae and
adults feed on items such as fur, hair, dander, hides, feathers, and
occasionally stored products such as dried fish, pet food and cheese. In the house, a likely source is dead insects
or other animals (boxelder bugs, attic flies, ladybugs, mice, etc.) that have
passed away inside walls or attics. This beetle is also found in bird nests,
animal remains, and bee and wasp nests.
The adult beetle is
just under 3/8 of an inch long and dark colored with a pale yellow band across
the center of the beetle. The grub or
larva is dark brown and very hairy in appearance with 2 curved dorsal spines on
the tail end. There may several
generations of the beetle each year.
The larvae are known to burrow into wood to construct chambers in which
to pupate. We have some reports of
structural damage to hen houses because of this behavior and in these cases the
most destructive phase of the life cycle occurs when the larvae pupate. It appears that the preferred pupation site
is soil where the larvae chew out a small pupation chamber. In the absence of soil, the pupation chambers
are constructed (chewed) in wooden structures or insulation inside walls and
ceilings.
The first step in larder
beetle control is to locate and dispose of all infested material. This may be difficult or next to impossible
if the beetles are feeding on dead insects in wall voids and other hidden
sites. After the infested material is
removed, the immediate area should be thoroughly sprayed with an indoor
formulation of permethrin (sold under a variety of brand names including raid
in the blue can) or bifenthrin (sold as Ortho Home Defense Max). Do not use these products in cupboards or
food preparation surfaces. When they are
found in cupboards, all food material should be inspected and discarded if
found to be infested.
Be sure to read and
follow all instructions and safety precautions found on the label before using
any pesticide.
Howard