Granary weevil

Definition

A species of small, flightless weevil (family Curculionidae) that is among the most destructive pests of stored cereal grains worldwide. Adults are reddish-brown to black, possess a pronounced rostrum with elbowed antennae, and measure 3–5 mm in length. Unlike the closely related rice weevil and maize weevil, S. granarius lacks functional wings and is exclusively associated with stored grain rather than field infestations. Females oviposit directly into intact kernels, and larvae complete development entirely within the grain, consuming the endosperm and leaving hollow, damaged seeds.

Etymology

From granary (a storehouse for grain) + weevil (any beetle of family Curculionidae, from Old English wifel, beetle)

Example

Granary weevil infestations in elevator silos can render wheat unmarketable when larval feeding reduces thousand-grain weight and promotes fungal contamination; fumigation with phosphine is often required for control.

Synonyms

• grain weevil
• Wheat weevil

Related Terms

• rice weevil
• Maize weevil
• Sitophilus
• Stored-product entomology
• Primary grain pest
• Curculionidae
• Grain protectant

Usage Notes

The common names granary weevil, grain weevil, and wheat weevil are used interchangeably for S. granarius, though 'wheat weevil' properly refers to its primary host association. Distinguished from the rice weevil (S. oryzae) and maize weevil (S. zeamais) by its flightless condition and lack of four pale reddish-brown spots on the elytra. All three Sitophilus species are frequently misidentified in pest surveys without close examination of wing vestiges and elytral pattern.