Food Industry Pests

INDIANMEAL MOTH (Plodia interpunctella)

One insect is found more often than any other on stored food and grain in the United States. This is the dreaded Indianmeal moth (IMM). Since they feed on any items containing grain or cereal products, the Indianmeal moth alone is responsible for most of the insect problems associated with the food industry. This is one of the easiest stored food insects to identify because the adults have a colorful appearance and the larvae (which look like yellow worms) leave a silken webbing trail wherever they crawl. Newly emerged adults have bi-colored (copper and tan) wings and measure about 1/2" from top to bottom. The IMM most commonly feeds on grain products including flour, cereal, nuts, bird seed and pet food.

WAREHOUSE BEETLE (Trogoderma spp.)

This small, oval beetle is a common pest of dog food facilities. The adult is a tiny black beetle with white or lightly colored markings on its back. The larvae are orange-brown in color and look hairy. Warehouse beetles feed primarily on animal products, but will readily feed on grain and cereal products. The hairs of the larvae can cause allergic reactions in sensitive individuals especially when swallowed. The life cycle from egg to adult can be completed in 43 days, but they can stay in diapause (hibernation) for up to two years.

RED AND CONFUSED FLOUR BEETLES (Tribolium spp.)

These insects, also called bran bugs are common pests of flour. They may infest any product made with grain, but they cannot infest sound (undamaged) grain. Flour beetles require about a month to complete their life cycle. Adults may live up to three years.

CIGARETTE BEETLE (Lasioderma serricorne)

This destructive insect is a serious pest of dried plant material. Its preferred food is dried tobacco leaves. The Cigarette beetle is a small brown beetle measuring 2-3 mm in length. The Cigarette beetle is closely related to the Drugstore beetle which can cause difficulty in identification. However, with some training they can be distinguished easily. The Cigarette beetle has wings covered in small hairs whereas the Drugstore beetle's wings have rows of punctations.

Trap placement and use for all above: Although there is no exact number of traps that you should place within a warehouse, we can give you some general guidelines. In general, in a warehouse you should place the traps 25 to 50 feet apart based on a grid pattern. Traps for all but flour beetle should be placed at eye level for easy access. Flour beetle traps should be placed level on floor or shelves. Lures are effective for two months after this they should be replaced with new ones.

GERMAN COCKROACH (Blattella germanica)

This nasty little guy will eat almost anything - even hair and fingernails. This insect is common in areas with access to food and water (i.e. break room, bathroom, food handling areas). The German cockroach is 5/8 inches in length and is brown in color. The life cycle from egg to adult takes about a month, and populations can become huge if not kept under control. A new pheromone trap has recently become available for this pest.

Trap placement and use: These traps should be placed in areas where cockroaches are likely to be encountered. The traps work best when placed along the edges of the floor and in corners. They also should be placed in the cabinet under the sink.

SAW-TOOTHED GRAIN BEETLE (Oryzaephilus surinamensis)

The Sawtoothed Grain Beetle is almost identical in appearance to the Merchants Grain Beetle (Oryzaephilus mercator). Both pests are scavenger feeders. They do not attack sound grains. They are cosmopolitan pests of broken stored grains, cereal products, dried fruit, oilseeds and other processed foods including oatmeal, flour, macaroni, nuts, sugar, chocolate, dried meats and many other products. Their physical design makes these pests notorious for entering packaged materials on the store shelves. Their extremely flat body design allows then to enter most seems in packaged foods.

Trap placement and use: The sex pheromone for the Saw-toothed Grain Beetle is still under development. Currently, a food attractant trap is being used to monitor for them.

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