Granary weevil

Systematic position: The granary weevil (Sitophilus granarius) belongs to the order Coleoptera and the family Curculionidae. It is considered one of the most destructive pests of stored grain worldwide, specifically adapted to thrive in granaries and food processing facilities.

Crops attacked: The species primarily infests a wide range of stored whole grains. Common hosts include wheat, rye, barley, oats, maize, and rice. In addition, it can occasionally infest stored products such as dried pasta, various seeds, and other cereal derivatives found in storage environments.

Biology and life cycle: Adult weevils are flightless and possess a characteristic snout. The female deposits a single egg into a hole bored into the grain kernel, then seals it with a gelatinous plug. The larva completes its entire development inside the kernel, feeding on the endosperm before pupating and emerging as an adult.

Nature of damage and economic impact: The damage is caused by the larvae feeding internally within the grain kernels. This results in significant weight loss and nutrient depletion of the grain. High infestation rates lead to the heating of the grain bulk, which facilitates the rapid growth of molds and pathogens, rendering the product unmarketable.

Control measures: Integrated pest management is essential to minimize losses. Recommended practices include:

• Ensuring grain is cleaned and dried to a moisture content below 14% prior to storage.
• Implementing regular fumigation protocols for storage facilities and grain bulks.
• Maintaining strict sanitary conditions in warehouses to eliminate breeding grounds.
• Monitoring grain temperature and quality frequently to detect early signs of infestation and prevent pest multiplication through cooling.