Guess the Pest! Week 3 Answer: Blister Beetle

David Owens, Extension Entomologist, owensd@udel.edu

Congratulations to Chris Griffith for correctly identifying last week’s GTP as a blister beetle. All blister beetles have a head and abdomen that is wider than the prothorax, giving them a ‘neck’. This species is in the genus Meloe, the larvae are parasitoids on bees. Other blister beetles attack grasshoppers, including the species most common in soybean fields, the striped blister beetle. Adults feed on foliage, and can be pests, especially on green leafy vegetables. Dr. Brust wrote a good article in last year’s WCU about them: https://sites.udel.edu/weeklycropupdate/?p=14128.

shiny black beetle with round head

Blister beetles get their name from a chemical in their blood, cantharidin, that causes nasty blisters and boils when it contacts skin. When threatened, beetles will break joints to release cantharidin. Blister beetles can be major problems with hay production. If accidentally crushed while being incorporated into hay the cantharidin has been known to cause sickness and even death of animals. Be careful with these critters!