Scientific name: Sitophilus oryzae Family: Curculionidae Order: Coleoptera Risk level: Very high Category: Beetle
? What is the rice weevil
Scientific name: Sitophilus oryzae
Family: Curculionidae
Order: Coleoptera
Risk level: Very high
Category: Beetle
The rice weevil (Sitophilus oryzae) can fly and spreads more quickly than the granary weevil. It has four light-red spots on its wings and infests rice, wheat, corn and barley.
Life cycle of the rice weevil
It undergoes complete metamorphosis. Eggs are laid directly on food, and the larva is the damaging stage. A full generation takes 4–8 weeks. Multiple generations may breed in an infested warehouse.
Distribution of the rice weevil
It occurs in food warehouses worldwide and is common in the Gulf, Saudi Arabia and Egypt, especially in hot warehouses.
Damage and risks associated with the rice weevil
It hollows out rice and wheat kernels, causing substantial quantitative and qualitative losses in warehouses.
Signs of a rice weevil infestation
Signs include adult insects around light sources; larvae and silken threads in food (moths); droppings and hollow grains caused by weevils and beetles; and small white eggs on food.
Where rice weevils are found
They infest rice, wheat and corn stored in silos and warehouses.
Rice weevil control methods
Monitor with pheromone traps. Spray the warehouse with pyrethroids. Fumigate stored products with phosphine or methyl bromide. For physical control, lower the temperature below 10°C or raise it above 55°C. Rotate stock using FIFO.
Rice weevil control products
Pyrethroids for warehouses, phosphine (PH₃) for fumigation, deltamethrin for residual spraying and diatomaceous earth for grain.
Requirements for controlling rice weevils in food facilities
FSSC 22000 Version 7: stored-product pests are high priority. Pheromone traps with weekly documentation are mandatory. BRCGS: stored-product pests in a product constitute a major Non-Conformance.
A fact about the rice weevil
Rice weevils can identify the temperature of grain masses very precisely. They concentrate in the warmer parts of a silo, where reproduction is faster, creating an uneven distribution that makes detection by random sampling more difficult.
Frequently asked questions about the rice weevil
Q: How do stored-product pests enter a facility?
A: Usually through incoming shipments. Carefully inspect samples from each shipment and quarantine new purchases.
Q: Is a low temperature enough to eliminate stored-product pests?
A: Yes. Temperatures below 10°C for two weeks stop reproduction and kill vulnerable stages. Temperatures below −18°C for three days kill all stages
