Blister beetle

The blister beetle is a beetle of the family Meloidae. They secrete cantharidin, a chemical that causes blisters. About 7,500 species are known worldwide. They are poisonous to predators.
Blister beetles go through several larval stages. The larvae mainly attack bees. They also eat grasshopper eggs.
Blister beetles are attracted to alfalfa and weeds during bloom.