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Carpet Beetle

They are small, oval insects, usually less than 1/4 inch long. Carpet beetle larvae are usually about the size of the adult beetle, 1/4 inch or less in length. Adult carpet beetles are commonly found indoors at windows. Carpet beetle larvae often wander about the infested location-- from room to room in a house. This behavior results in spreading the infestation throughout the house.

Adults can mate and reproduce without feeding. Females can lay from 30 to 100 eggs, depending on the species. Eggs are laid in lint, behind and under baseboards, in floor cracks, or other dark and protected locations. Eggs hatch in one to three weeks.

The larval stages cause damage to a variety of material. Their preferred food varies with the species, but all carpet beetle larvae can feed on wool carpets and other wool products, furs, hides, horns, feathers, hair, and silk. They will also feed on linen, cotton, and rayon if these fabrics are soiled with juice, food, or animal excreta. They can be pests in cereals, stored grains, nuts, meal, Indian corn, red pepper, and similar products.

Drug Store Beetle

The drugstore beetle attacks such a wide variety of foods and material that one anonymous quote states that it "eats anything but cast iron." It gets its name from its habit of feeding on prescription drugs. It also feeds on flours, dry mixes, breads, cookies, chocolates and other sweets, and spices. Non-food material includes wool, hair, leather, horn, and museum specimens. Larval feeding accounts for the greatest amount of damage. Drugstore beetles harbor symbiotic yeasts that produce B vitamins. The yeasts are deposited on the eggs as they pass through the oviduct and are consumed by the larvae during egg hatch. These yeasts enable the drugstore beetle to feed and survive on many foods and other items of poor nutritional quality.

Powderpost Beetle

Powderpost beetles infest softwoods (pine, spruce, fir) and hardwoods (oak, maple), and make small (1/8 inch), round holes in the wood.

In modern log houses, powderpost beetles are usually encountered in the lumber after the first year or two. The first evidence is small holes with fine sawdust streaming from them, usually in the spring of the year. Treatment is the same as for the Old House Borer.

Old House Borer

Despite the name, these beetles are just as likely to be found in new homes. The larvae feed little during the winter months of December through February. The larvae can live in seasoned softwood for several years. When the larvae are full grown, which usually takes about five years, they emerge through oval holes in the surface of the wood. Emergence occurs during June and July. During the first few years of feeding, the larvae cannot be heard, but when they are about four years old the chewing sounds are audible.

Damage occurs to the wood in houses. The actual structural damage caused by these beetles depends on the number of larvae feeding, the extent of the infestation (how many years), and whether there has been a reinfestation.

Control of old house borers involves the use of insecticides applied to the surface of wood or the use of an insecticidal gas (fumigation). When there is an extensive and active infestation of this insect, fumigation may be the best control method. However, limited infestations can be controlled by applying insecticides to the surface of the wood to prevent re-infestation and, perhaps, kill larvae that may feed close to the surface and contact the chemical just below the surface.

Confused Flour Beetle

Confused flour beetles are 1/8-inch long, reddish-brown in color and have a flat body. Their antennae end in a three-segmented club with the end being abrupt.

Female beetles each lay 300 to 400 eggs in flour or other foods during a period of five to eight months. Within 5 to 12 days, these eggs hatch into slender larvae. The larval period varies from 22 to more than 100 days, and pupation takes about 8 days. Adults can live for 3 years or more.

The Confused flour beetle is a scavenger and must rely on other insects to damage grain before it can feed on it. Because of this beetle’s small size, it frequently invades storage containers. These beetles breed in
damaged grain, grain dust, high-moisture wheat kernels, flour, etc. They are prolific and quite damaging.

The Confused and Red flour beetles are known as "bran bugs" because they primarily attack milled grain products such as flour and cereals. Flour and other processed food products heavily infested by these beetles often develop a grayish tint and in some cases a disagreeable odor. These beetles often hitchhike into the home in infested flour and can multiply into large populations. Some survive on food accumulations in cabinet cracks and crevices.

Sawtooth Grain Beetle

The adults are very flat, narrow, dark brown in color and 0.1 inch long. They are recognized by the sawtooth projections on the sides of the middle segment. Larvae are white to pale yellow and 0.1 inch at maturity. The eggs are deposited on cracks in grain kernels. Adults and larvae require fine material to survive and cannot feed on whole kernels. They can build up to high numbers in stored grain. The sawtooth grain beetle is a common pest.

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