The Granary Weevil (Sitophilus granarius) is one of the oldest known grain pests, with evidence of its association with stored grain dating back to ancient Egypt. It is closely related to the Rice Weevil but has one important difference: it is completely wingless and cannot fly. Adults are small (1/8–3/16 inch), uniformly dark reddish-brown to nearly black, with the characteristic weevil snout and fine longitudinal striations on the wing covers. Unlike the Rice Weevil, there are no pale spots on the wing covers. Like the Rice Weevil, the Granary Weevil is a primary pest of whole grains — females deposit eggs inside grain kernels and larvae develop entirely within the kernel. It attacks wheat, barley, rye, oats, corn, and other whole grains. Because it cannot fly, the Granary Weevil spreads only through infested grain and grain products — it does not disperse between storage locations on its own. In Arizona, it is most commonly found in farm grain storage, feed stores, and homes that store large quantities of whole wheat or barley. It prefers slightly cooler temperatures than the Rice Weevil and is more common in commercial grain storage than in household pantries.
👁Warning Signs
Small (1/8–3/16 inch) uniformly dark reddish-brown beetles with elongated snout found in stored wheat, barley, or whole grains. Round exit holes in grain kernels. Hollow grain kernels. Cannot fly — found only crawling in grain.
⚠Health & Property Risks
Destroys grain kernels from the inside. Significant losses in stored wheat, barley, and whole grains. Cannot fly — spreads only through infested grain. More common in commercial grain storage than household pantries.
Prevention Tips
Store whole grains in airtight containers. Inspect purchased grain. Freeze new grain purchases for 1 week. Rotate grain stocks. Inspect farm and commercial grain storage regularly.
🛡Professional Treatment
Discard all infested grain. Freeze suspect grain at 0°F for 1 week. Airtight storage for remaining grain. Clean and vacuum storage containers.
Frequently Asked Questions — Granary Weevil
The Granary Weevil (Sitophilus granarius) is uniformly dark reddish-brown to nearly black; no pale spots on wing covers; fine longitudinal striations and typically measures 1/8–3/16 inch; elongated snout; wingless. The Granary Weevil (Sitophilus granarius) is one of the oldest known grain pests, with evidence of its association with stored grain dating back to ancient Egypt. It is closely related to the Rice Wee.
The Granary Weevil poses a moderate risk. Destroys grain kernels from the inside. Significant losses in stored wheat, barley, and whole grains. Cannot fly — spreads only through infested grain. More common in commercial grain storage than household pantries.
In Arizona, granary weevils are most often encountered in the following situations: Small (1/8–3/16 inch) uniformly dark reddish-brown beetles with elongated snout found in stored wheat, barley, or whole grains. Round exit holes in grain kernels. Hollow grain kernels. Cannot fly — found only crawling in grain.
The Granary Weevil is most active during: Year-round in grain storage; prefers slightly cooler temperatures than Rice Weevil. Arizona's warm desert climate can extend activity periods compared to other states, so year-round vigilance is recommended in the Phoenix metro and surrounding areas.
Store whole grains in airtight containers. Inspect purchased grain. Freeze new grain purchases for 1 week. Rotate grain stocks. Inspect farm and commercial grain storage regularly.
Discard all infested grain. Freeze suspect grain at 0°F for 1 week. Airtight storage for remaining grain. Clean and vacuum storage containers.
Left unchecked, Granary Weevil infestations can cause significant structural or food-storage damage over time. Destroys grain kernels from the inside. Significant losses in stored wheat, barley, and whole grains. Cannot fly — spreads only through infested grain. More common in commercial grain storage than household pantries. Early detection and professional treatment are the most cost-effective approach — contact Pest Control Bros for an inspection at the first sign of activity.
Dealing with Granary Weevil?
Pest Control Bros LLC serves Maricopa, Chandler, Casa Grande, Tempe, Gilbert, and Mesa. No contracts. Free inspections. Same-week service.
