Khapra Beetle

Trogoderma granarium, known as the khapra beetle, is a highly destructive pest of stored products, belonging to the family Dermestidae, order Coleoptera. Adults are small, oval-shaped beetles, 1.8-3.0 mm long, with a dark brown to black coloration and often indistinct reddish-brown markings on their elytra, which may also be covered with fine hairs. Larvae are yellowish-brown, covered in dense, reddish-brown hairs and characteristic 'bottlebrush' hairs, and can reach up to 6 mm in length. They are the most damaging stage. Eggs are minute, oval, and white. The life cycle duration varies significantly with temperature and food availability; at 320C and optimal food, it can be completed in 30-45 days, but under adverse conditions, it can extend to several months or even years due to larval diapause.

Khapra beetle larvae are internal and external feeders on a wide range of stored products, especially cereal grains, oilseeds, and dried fruits, impacting quality and facilitating mold growth. Adults are short-lived, do not feed or fly, and their primary function is reproduction. Females lay 50-90 eggs loosely in infested materials. Larvae exhibit a strong thigmotactic response, preferring to hide in cracks and crevices when not feeding. They can survive for long periods (up to three years) without food through diapause, a critical factor in their persistence. Dispersal is often passive, through infested commodities.