The Cowpea Weevil (Callosobruchus maculatus), also known as the Southern Cowpea Weevil or Cowpea Bruchid, is one of the most destructive pests of stored legumes worldwide and a significant pest in Arizona, particularly in homes and stores that stock cowpeas, black-eyed peas, mung beans, lentils, and chickpeas. Like the Bean Weevil, it is a seed beetle (bruchid) rather than a true weevil. Adults are small (1/8 inch), oval, reddish-brown to brownish-black with a distinctive pattern of pale and dark patches on the wing covers and a characteristic pale spot on each side of the abdomen tip. Adults can fly and are attracted to light. Females lay eggs directly on bean seeds, and larvae bore inside and develop entirely within the seed. The Cowpea Weevil is particularly well-adapted to warm, dry conditions and thrives in Arizona's desert climate — it can complete a generation in as little as 3 weeks in summer heat, making it one of the fastest-reproducing stored-product pests in the state. Heavily infested bean stores can be completely destroyed within a single season. The Cowpea Weevil can also infest beans in the field before harvest, introducing infestations into storage.
👁Warning Signs
Small (1/8 inch) reddish-brown to brownish-black oval beetles with pale and dark wing cover pattern found in stored cowpeas, black-eyed peas, or mung beans. Round exit holes in bean seeds. Hollow seeds. Adults may be found flying near bean storage.
⚠Health & Property Risks
One of the fastest-reproducing stored-product pests in Arizona's warm climate — can destroy entire bean stores within weeks. Attacks beans both in field and in storage. Significant losses in stored cowpeas, black-eyed peas, and mung beans.
Prevention Tips
Store legumes in airtight containers. Inspect purchased beans. Freeze new bean purchases for 1 week. Rotate bean stocks. Refrigerate or freeze long-term bean storage.
🛡Professional Treatment
Discard all infested beans. Freeze suspect beans at 0°F for 1 week. Airtight storage for remaining beans. Clean and vacuum storage containers.
Frequently Asked Questions — Cowpea Weevil
The Cowpea Weevil (Callosobruchus maculatus) is reddish-brown to brownish-black with pale and dark patches on wing covers; pale spot on each side of abdomen tip and typically measures 1/8 inch; oval. The Cowpea Weevil (Callosobruchus maculatus), also known as the Southern Cowpea Weevil or Cowpea Bruchid, is one of the most destructive pests of stored legumes worldwide and a significant pest in Ari.
The Cowpea Weevil poses a moderate risk. One of the fastest-reproducing stored-product pests in Arizona's warm climate — can destroy entire bean stores within weeks. Attacks beans both in field and in storage. Significant losses in stored cowpeas, black-eyed peas, and mung beans.
In Arizona, cowpea weevils are most often encountered in the following situations: Small (1/8 inch) reddish-brown to brownish-black oval beetles with pale and dark wing cover pattern found in stored cowpeas, black-eyed peas, or mung beans. Round exit holes in bean seeds. Hollow seeds. Adults may be found flying near bean storage.
The Cowpea Weevil is most active during: Year-round indoors; one of the most heat-tolerant stored-product pests; most rapid reproduction in Arizona's summer heat. 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 legumes in airtight containers. Inspect purchased beans. Freeze new bean purchases for 1 week. Rotate bean stocks. Refrigerate or freeze long-term bean storage.
Discard all infested beans. Freeze suspect beans at 0°F for 1 week. Airtight storage for remaining beans. Clean and vacuum storage containers.
Left unchecked, Cowpea Weevil infestations can cause significant structural or food-storage damage over time. One of the fastest-reproducing stored-product pests in Arizona's warm climate — can destroy entire bean stores within weeks. Attacks beans both in field and in storage. Significant losses in stored cowpeas, black-eyed peas, and mung beans. 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 Cowpea Weevil?
Pest Control Bros LLC serves Maricopa, Chandler, Casa Grande, Tempe, Gilbert, and Mesa. No contracts. Free inspections. Same-week service.
