From the internets...
Stored product beetles include species like red and confused flour beetles, cigarette beetles, drugstore beetles, warehouse beetles, and weevils. The second most common stored product insect is the
warehouse beetle,
Trogoderma variabile. Warehouse beetles are in the family Dermestidae which include the Khapra beetle, carpet beetles, hide beetles and larder beetles.
An important characteristic in the dermestid family is their unique larvae. Larvae have spear-shaped hairs called setae in which they use as a defense mechanism, similar to porcupine quills. Larvae molt about six times and leave behind cast skins. The setae on cast skins can easily contaminate food, cause allergic reactions, and irritations if ingested. A warehouse beetle larvae caused an FDA recall of 1 million packages of baby formula in 2010. Only one package was actually confirmed infested through a customer complaint. Dermestid larvae can be very longed lived if conditions are unfavorable. Some dermestid larvae have been recorded to survive more than 5 years without food.
Warehouse beetles can be identified with their dark mottled color pattern with no scales. It can be difficult to distinguish the warehouse beetle between other insects in the same Trogoderma genus, such as the Khapra beetle. However, the Khapra beetle is unable to fly whereas the warehouse beetle can. Warehouse beetle and Khapra beetle share the same sex pheromone. A good way to distinguish between these two species is to place out
hanging pheromone traps and
floor pheromone traps. If insects are only caught in-floor traps and not hanging traps, then you may have Khapra beetle. The Khapra beetle is a quarantine pest and proper identification should be performed by a governing agency like the USDA.
Warehouse beetles can complete their life cycle in 30 60 days depending on environmental conditions. They feed on dry grain-based or high-protein foods like corn, wheat, rice, and milk powder.
Adults generally orient towards warmer dry dark locations and can survive on residual food dust inside hollow block walls, or ceiling tiles. Adults live for 1 2 months and females can lay 100 eggs.