Lyctid Powderpost Beetles

Lyctids rarely infest wood older than five years. Thus, infestations generally are encountered in new homes or newly-manufactured articles. In almost all cases, infestation results from wood that contained eggs or larvae at the time it was placed in the home. Typically, the infested article was constructed from wood which was improperly dried or stored.

Anobiid Powderpost Beetles

Anobiid powderpost beetles may attack both hardwoods and softwoods so infestations may be found in all the same places as Lyctid beetles, as well as in structural timbers (beams, sills, joists, studs, subflooring, etc). Maple, beech, poplar and pine are especially susceptible to attack. Anobiids prefer to infest damp wood; therefore, infestations usually begin in moist, poorly-ventilated areas such as crawl spaces, basements, garages and utility sheds. Under favorable conditions of moisture and temperature, infestations may spread upwards into walls and upper levels of the structure, including furniture. Infestations may occur because of using infested lumber, or from beetles flying in from outdoors or being carried in on firewood. Infestations develop slowly, but wood can be reinfested.

Grain Weevils

Weevils are among the most destructive stored product pests. Mouthparts of adults form elongated snouts characteristic of all weevils. Adults can live for four to five months.

Females typically lay 50 to 200 eggs. Females use their strong mandibles to chew small holes into grain kernels. A single egg is placed in each hole. The small, white, legless larvae hatch, feed and develop inside kernels of grain. They can survive in grains for at least 10 weeks at temperatures as low as 41°F.

Wheat, corn, oats, and sorghum are just some of their preferred foods.

Lesser Grain Borer

The adult lesser grain borer is 1/8 inch long cylindrical beetle with a shiny dark brown or black body. The last three segments of the antennae are enlarged on one side. The body surface is rough and the head is hidden from view. Powerful jaws allow the insect to bore into wood as well as grain.

Adult lesser grain borers are strong fliers and long-lived. Females lay up to 500 eggs singly or in clusters in loose grain. Their C-shaped white larvae have dark heads and short legs. They burrow into and feed inside nearly all types of grain. Infested grain has a characteristic sweet and slightly pungent odor.

Indian meal moth adult (photo: Pest.Kill.org)

Indian meal moth larvae silk and frass (waste) in infested nuts

Indian Meal Moth

The Indian meal moth is one of the most common pests of grain storage and processing facilities and warehouses. Adults are distinctive. The outer two-thirds of the front wings are copper brown, the bases are grayish white. The hind wings are pale gray. The head and thorax are reddish brown. Adult Indian meal moths are weak fliers that are usually active for only a few hours in the evening. Usually, they remain close to the infested material.

Female adult Indian meal moths lay eggs singly or in groups directly on food material. The small, pale yellow eggs hatch in about three days. Larvae emerge and feed in the top 4” to 6” of the infested commodity. They are usually dirty white but may have a green or pink tint. Full-grown caterpillars are about 1/2 inch long with a brown head. Heavily infested materials are covered with a fine, web-like mesh of silk spun by the caterpillars. Infestations may be discovered when full-grown caterpillars crawl away from their food to spin a cocoon for pupation.

Flour Beetles

Adult confused and red flour beetles are long, flat, shiny, reddish brown insects measuring about 1/7 inch long. Female flour beetles lay several hundred small, whitish eggs directly on the food source. The female covers the eggs with a sticky secretion to which bits of the food adhere. Small, brownish white larvae hatch in five to twelve days. They are full grown in one to four months. A full-grown larva is about 3/16 inch long and tinged with yellow.

Flour beetle larvae feed on broken kernels, flour, meal and other starchy materials. They are often hard to detect because they cover themselves with bits of the food they infest. They may appear as tiny lumps in the flour. The larvae pupate and transform into adults. Flour beetles do not penetrate whole grain kernels or undamaged grain. Instead, these secondary feeders cause damage by scraping the surface of foods or eating finely ground material. Their preferred foods include grains and grain products, peas, beans, flour, dried fruits, shelled nuts, spices and other commodities. These beetles may leave a bad odor that affects the taste of infested products.