This 1/8 inch long, flattened, reddish brown beetle may appear somewhat shiny. The shield behind the head (pronotum) has minute punctures and the wing covers (elytra) are grooved (striate) with sparse punctures.
Adult beetles are active and move about irregularly. They can live for over a year. Eggs laid by females hatch in 5 to 12 days. Larvae are white, tinged with yellow, slender and cylindrical. They develop through 5 to 12 stages (instars) and grow to about 3/16 inch long over as few as 30 days. They have two short appendages on the end of the last abdominal segment. There may be 5 generations per year.
Adults and larvae feed throughout stored food primarily in milled or prepared products. They are perhaps the most common pest of processed flour.
Sanitation is a very important factor in the control of the yellow mealworm, followed by the use of an approved structural insecticide. Also ensure that wall and floor cracks are repaired and that basement areas are kept as dry as possible.