Sawtoothed grain beetle (Oryzaephilus surinamensis)

Type of pest: Secondary pest.

Distribution: Worldwide. O. surinamensis is cold-tolerant.

Identification: Adults are 3 mm, dark brown to dark grey, highly flattened and parallel-sided. The thorax has three longitudinal ridges, with the side of thorax having six tooth-like projections. The length of head behind the eye is long in O. surinamensis, short in O. mercator. Larvae: campodeiform.

Similar species:Ahasverus, Cathartus.

Life cycle: Optimal cycle in 20 days with 30-33 º C, 70-90% RH. At 20 º C the entire lifecycle is 3-4 months. Adult females lay 300-400 eggs. Eggs are laid around the product. The larvae are mobile and external feeders. The larvae develop most rapidly at 20 to 35 º C, and during the larval stage 3 or 4 molts occur. Adults are long-lived, very active, walking long distances, eating the product and flying.

Commodities infested: O.surinamensis has a preference for grain products, while O. Mercator prefers dried fruits and oilseeds. O. surinamensis lives in warehouses and in households in all kinds of plant material. The grain and nuts are eaten or to be eaten, which creates dust. Strongly contaminated batches are unsuitable for incorporation into products intended for human consumption. O. surinamensis also indicates the presence of weevils and other commodity feeders such as the rice flour beetle.

Preventive measures include: keep storage and production area clean and dry, maintain relative humidity in storage between 40% and 60% and ensure that packaging materials pallets etc. are clean and dry before storage.

Treatment: Controlled Atmosphere for infestation in products
Treatment: Heat Treatment for infestation in buildings