Adult varied carpet beetles are about 1/16 to 1/8 inches long, and generally oval in appearance. The back of these insects are spotted with grey-yellow, brown, and white scales.
The larvae are 3/16 to ¼ inches long, and wider at the end of the body than at the head. They are covered with a series of light and dark-brown stripes that run across the body. Carpet beetle larvae have three dense tufts of bristles at the rear end.
Female carpet beetles lay about 40 eggs in a lifetime. The eggs hatch in 10 to 20 days, and the larvae develop in 222 to 323 days, remaining as pupae for just 10 to 13 days. There is one generation of carpet beetles per year. Adults live from 14 to 44 days.
The carpet beetle larvae feed on a wide variety of foods, including carpets, woolens, skins, furs, stuffed animals, leather bindings on books, feathers, silk, and plant products. Adults feed on pollen, are good fliers, and infiltrate homes through open doors and windows.
The initial step in carpet beetle control is the correct identification of the pest, followed by a thorough investigation that targets and eliminates the infestation source. Infested food should be discarded, and carpets, rugs, and clothing should be brushed or cleaned. Application of a residual insecticide in cracks, crevices, and the immediate areas around the infestation may be necessary depending on severity.
Adult flour beetles are red-brown in colour, slender, and about 1/8-inch long. Both species (red and confused) look similar, but can be distinguished by looking at the antennae.
The confused flour beetle’s antennae gradually enlarge toward the tip, ending in a four segmented club. The red flour beetle’s antennae become club-like abruptly, and the club has three segments.
(Confused Flour Beetle)
(Red Flour Beetle)
Over the span of the beetle’s two to three year lifetime, females produce 300 to 500 eggs. They lay two to three clear, white, sticky eggs daily in cracks, bags, or the mesh of flour bags. The eggs hatch in 12 days, and the larvae undergo 5 – 12 molts, completing development in about 30 days. The life cycle, egg to egg, comes full circle in 49 to 90 days.
Confused and red flour beetles are major pests when it comes to flour. They cannot feed on whole grains, but are found abundantly in grain dust, flour, dried fruit, nuts, chocolate, snuff, spices, rodent baits, and drugs.
Infested flour or other stored products should be identified and discarded. The cupboards, cabinets, closets, shelves, and pantry where the infestation has manifested should be well vacuumed to eliminate spilled flour and other food dusts. Storage areas and sites of infestation should also be treated with liquid or dust formulations as another precaution against infestation.