The Rice Weevil (Sitophilus oryzae) is one of the most destructive stored-grain pests in the world and a significant pest of stored rice, wheat, corn, barley, oats, and other whole grains in Arizona homes and agricultural storage facilities. Adults are small (1/8 inch), dark reddish-brown to nearly black, with four pale reddish-orange or yellowish spots on the wing covers and the characteristic elongated snout (rostrum) of weevils. The wing covers have fine longitudinal striations. Adults can fly and are attracted to light. Like the Angoumois Grain Moth, the Rice Weevil is a primary pest — females chew a small hole in a grain kernel, deposit a single egg inside, and seal the hole with a gelatinous plug. The larva develops entirely inside the kernel, consuming the contents, and the adult emerges by chewing an exit hole. This internal development makes infestations difficult to detect until adults begin emerging in large numbers. In Arizona, the Rice Weevil is most commonly found in stored rice, whole wheat, and corn, and is a significant pest in homes that store large quantities of these grains. In Arizona's warm climate, it can complete a generation in 4–6 weeks.
👁Warning Signs
Small (1/8 inch) dark reddish-brown beetles with elongated snout and four pale spots on wing covers found in stored rice, wheat, or corn. Round exit holes in grain kernels. Hollow grain kernels. Adults may be found flying near grain storage.
⚠Health & Property Risks
Destroys grain kernels from the inside — damage invisible until adults emerge. Significant losses in stored rice, wheat, corn, and whole grains. Can fly — disperses between grain sources. Rapid reproduction in Arizona's warm climate.
Prevention Tips
Store rice and whole grains in airtight containers. Inspect purchased grain products. Freeze new grain purchases for 1 week to kill eggs and larvae inside kernels. Rotate grain stocks regularly.
🛡Professional Treatment
Discard all infested grain. Freeze suspect grain at 0°F for 1 week. Airtight storage for remaining grain. Vacuum and clean storage containers and shelves.
Frequently Asked Questions — Rice Weevil
The Rice Weevil (Sitophilus oryzae) is dark reddish-brown to nearly black; four pale reddish-orange or yellowish spots on wing covers and typically measures 1/8 inch; elongated snout (rostrum). The Rice Weevil (Sitophilus oryzae) is one of the most destructive stored-grain pests in the world and a significant pest of stored rice, wheat, corn, barley, oats, and other whole grains in Arizona h.
The Rice Weevil poses a moderate risk. Destroys grain kernels from the inside — damage invisible until adults emerge. Significant losses in stored rice, wheat, corn, and whole grains. Can fly — disperses between grain sources. Rapid reproduction in Arizona's warm climate.
In Arizona, rice weevils are most often encountered in the following situations: Small (1/8 inch) dark reddish-brown beetles with elongated snout and four pale spots on wing covers found in stored rice, wheat, or corn. Round exit holes in grain kernels. Hollow grain kernels. Adults may be found flying near grain storage.
The Rice Weevil is most active during: Year-round indoors; most rapid reproduction in warm months; thrives in Arizona's warm storage conditions. 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 rice and whole grains in airtight containers. Inspect purchased grain products. Freeze new grain purchases for 1 week to kill eggs and larvae inside kernels. Rotate grain stocks regularly.
Discard all infested grain. Freeze suspect grain at 0°F for 1 week. Airtight storage for remaining grain. Vacuum and clean storage containers and shelves.
Left unchecked, Rice Weevil infestations can cause significant structural or food-storage damage over time. Destroys grain kernels from the inside — damage invisible until adults emerge. Significant losses in stored rice, wheat, corn, and whole grains. Can fly — disperses between grain sources. Rapid reproduction in Arizona's warm climate. 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 Rice Weevil?
Pest Control Bros LLC serves Maricopa, Chandler, Casa Grande, Tempe, Gilbert, and Mesa. No contracts. Free inspections. Same-week service.
