Common Types of Food Storing Beetles
Granary and Rice weevils
Both granary and rice weevils, often known as “snout weevils,” penetrate and feed on the internal portions of whole grains during the larval (immature) stage, making early detection of infestations difficult. They are usually found in grain storage facilities or processing plants, infesting wheat, oats, rye, barley, rice, and corn. Although not often found in the home, sometimes they infest table beans, acorns, chestnuts, birdseed, sunflower seeds, and ornamental corn. They are rarely found in macaroni and spaghetti. Homeowners sometimes refer to infested foods as “weevilly.” Granary and rice weevils do not bite or sting humans or pets, spread disease, or feed on or damage the house or furniture.
Red flour beetle
The red flour beetle is a tenebrionid beetle. It is a worldwide stored product pest. Red flour beetles attack stored grain products (flour, cereals, pasta, biscuits, beans, nuts, etc.) causing loss and damage. They may cause an allergic response but are not known to spread disease and cause no damage to structures or furniture. The red flour beetle is of Indo-Australian origin and less able to survive outdoors than the closely related species Tribolium confusum. It has, as a consequence, a more southern distribution, though both species are worldwide in heated premises. The adults are long-lived and may live for more than three years.
Confused flour beetle
The confused flour beetle (Tribolium confusum), a type of darkling beetle known as a flour beetle, is a common pest insect known for attacking and infesting stored flour and grain. They are one of the most common and most destructive insect pests for grain and other food products stored in silos, warehouses, grocery stores, and the home.
Both the confused flour beetle and red flour beetle are small, about 1/8 to 1/4 inch in length, and reddish-brown in color. The primary distinguishing physical difference is the shape of their antennae: the confused flour beetle’s antennae increase gradually in size and have four clubs, while the red flour beetle’s antennae have only three. Additionally, red flour beetles have been known to fly short distances, while confused flour beetles do not.
Sawtoothed Grain Beetle
Sawtoothed Grain Beetle (Oryzaephilus surinamensis) attacks cereals, dried fruits & flour etc. This beetle is small and about 2-3mm in length and brown in color. The margins of the thorax are saw-like, bearing six projections on each side, and this is reason for its common name.
Hide Beetle (Dermestes maculatus) is large beetle that is attracted to dreid or cured meats with high protein content. Adult beetles are about 6-13mm in length, dark gray to black in color with whitish hairs on the edges of the thorax.
Cowpea weevil (Callosobruchus maculatus) are small beetles, 3-5mm in length, reddish in color, and the body narrows evenly toward the small head. This genus will attack dried beans and can be a serious pest in stored beans. Adults move about readily and can infest seeds in the field, but can also breed continuously in stored dry cowpeas. Larvae typically develop inside the dried peas.