Diacon: Insect Identification

Insect Identification

Lesser Grain Borer

Lesser Grain Borer

The Lesser Grain Borer is a small but powerful grain infesting beetle. The adult feeds on whole or cracked grain, and the larvae develop inside kernels destroying internal contents. Both the adults and their larvae have powerful jaws used to riddle grain, creating large, irregularly shaped holes, and rendering grain to dust. Grain infested with the Lesser Grain Borer has a characteristic sweet and slightly pungent odor. They are prominent in wheat, but commonly infest rice, barley and all other cereal grains. The Lesser Grain Borer is also a strong flier and is capable of rapidly spreading infestations.

Saw-toothed Grain Beetle

Saw-toothed Grain Beetle

The Saw-toothed Grain Beetle is a common stored-food product pest. The adults and their larvae are external feeders, with the adults capable of penetrating most types of packaging. These insects have running legs much like cockroaches and have been documented to penetrate even the most “tightly sealed” packaging. These insects have been found to infest cereals, cornmeal, cornstarch, popcorn, rice, dried fruits, rolled oats, bran, macaroni, and other foodstuffs making them unsalable and unpalatable. These insects are known for contaminating more food than they can consume.

Confused Flour Beetle

Confused Flour Beetle

Commonly known as bran bugs, Confused Flour Beetles primarily feed on grain dust, broken kernels and the milled grains in flour and cereal. Confused Flour Beetles are true to their name, and are most abundant and damaging to the flour industry. Badly infested flour is characterized by sharp odor and moldy flavor. They have also been found in barley, corn, millet, oats, rice, rye, and wheat. Adults are very active, and can be found both on the surface and deep within contaminated food material.

Indian Meal Moth

Indian Meal Moth

The Indian Meal Moth is considered particularly troublesome to grain storage because of the damage inflicted by its larvae. The larvae feed on the grain’s germ decreasing germination. They also produce webbing that causes grain to stick together preventing proper aeration. Beyond grains, larvae also feed on cereals and a wide variety of foods and feeds ranging from dried fruit to seed to cornmeal to wild bird feed to sunflowers to animal feed. Larval infestations are usually top feeders located 4 to 6 inches from some type of surface such as unsealed doors or aeration fan openings.

Almond Moth

Almond Moth

Primarily a pest to the tropics, the Almond Moth goes by the nicknames “Cocoa Moth” and “Tropical Warehouse Moth” in the temperate regions where it is found. The Almond Moth attacks a wide-variety of products, but is a major pest of stored nuts. Though they are able to pupate externally, the Almond Moth larvae tend to pupate inside nuts. The larvae also prefer dried fruits, grain, seed and cereal products. Found in concealed locations the larvae and adults travel well, and thrive in the warmer climates of southern states.

Merchant Grain Beetle

Merchant Grain Beetle

Much like the Saw-toothed Grain Beetle, the Merchant Grain Beetle is an external feeder capable of penetrating most types of packaging - the main difference being the Merchant Grain Beetle’s ability to fly. These beetles are capable of chewing into unopened paper or cardboard boxes, through cellophane, plastic, and foil wrapped packages. Once infestations are established, populations build rapidly spreading into other stored foods and food debris accumulated in corners, cracks and crevices.

Rusty Grain Beetle

Rusty Grain Beetle

The Rusty Grain Beetle is a cosmopolitan pest that often infests stored grain in the northern United States and Canada. The adult beetles are rectangular, reddish-brown, less than two millimeters long with long antennae that look bead-shaped when the insect is magnified. Larvae are worm-like, white, and have two brown projections on the tail end. The Rusty Grain Beetle prefers high moisture grain or moist, decaying food. Heavy infestations of Rusty Grain Beetles can cause grain to heat and spoil.

Red Flour Grain Beetle

Red Flour Grain Beetle

The Red Flour Grain Beetle (closely related to the Confused Flour Beetle) is reddish-brown in color and its antennae end in a three-segmented club. The head of the Red Flour Grain Beetle is visible from above, does not have a beak and the thorax has slightly curved sides. It is commonly found in the household, but originates from infested grain or from dry food products such as cereals, flours, cake mixes, cornmeal, crackers, dry pet food, chocolate, nuts and seeds. Both adults and their small off-white larvae will be found in infested food items.