Cowpea weevil, Callosobruchus maculatus
(Coleoptera: Bruchidae)

The cowpea weevil will feed on beans, it has caused damage to soybeans in storage, but is primarily a pest of cowpeas. The adults do not eat legume seeds. Despite its name, it is not a true weevil. This species has a worldwide distribution.

This beetle is similar in size and habits to the bean weevil. The adult is light olive-brown in color, mottled with darker brown and gray and reaches 2.5 to 4 mm in length. Each wing cover has a large dark spot at the middle outer edge and the adult is a strong flier. The legs are reddish and the thorax narrows towards the head. In front of the wing covers is a cream colored spot on the hind edge of the thorax. Adult females lay up to 100 eggs, usually one to three eggs per seed. Larvae live inside a bean, which may include several larvae, and leave round holes when they emerge as adults. The life cycle can be completed in 21 to 36 days. Although the larva will feed on beans, only in a cowpea does it successfully complete its life cycle. Adults live an average of 15 days in warm weather (longer during cool weather) and there are usually six to seven generations per year.

Images

To save the Web-optimized images shown below to your hard drive:

PC users: right click to "Save Picture (or Image) As..."
Mac users: click and drag to your desktop.


Cowpea weevil, Callosobruchus maculatus, adults.
(Photographer: L.J. Buss, University of Florida)

Click to access Display and Print quality images.


Adult cowpea weevil, Callosobruchus maculatus.
(Photographer: J.L. Castner, University of Florida)

Click to access Display and Print quality images.


Cowpea weevil, Callosobruchus maculatus, larvae.
(Photographer: L.J. Buss, University of Florida)

Click to access Display and Print quality images.


Cowpea weevil, Callosobruchus maculatus, eggs.
(Photographer: L.J. Buss, University of Florida)

Click to access Display and Print quality images.


Cowpea weevil, Callosobruchus maculatus, life stages.
(Photographer: L.J. Buss, University of Florida)

Click to access Display and Print quality images.


Cowpea weevil, Callosobruchus maculatus, damage to
cowpeas.
(Photographer: L.J. Buss, University of Florida)

Click to access Display and Print quality images.



Return to Index


Copyright © 2005 University of Florida