Biting Merchant Giant Beetle from California

Found in San Rafael, California two week ago. Bite very painful. Very small like 1/8-1/4 inch photos xoomed (enlarged)

Jonathan K.

This is a Merchant Grain Beetle, 

Oryzaephilus mercator, a common household pest.  According to BugGuide (link  “Adults and larvae feed primarily on cereal products, particularly oatmeal, bran, shelled sunflower seeds, rolled oats, and brown rice”. While they are not known for biting humans, they do possess mandibles, so a bite is possible.


  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

Leave a Comment