True blister beetles (Coleoptera: Meloidae) get their common name from their ability to produce cantharidin, a substance that can cause chemical burns. They produce this compound to ward off potential predators, including humans. A person who touches one of these beetles can suffer blisters on the affected areas of their skin, and ingesting them can be fatal.
Similar to the true blister beetles are the false blister beetles (Coleoptera: Oedemeridae), and one particular species is shown here. Many species in this family look superficially similar to true blister beetles, and some species even produce cantharidin. Overall, however, false blister beetles are generally harmless.
These beetles are widespread throughout the world, with nearly 100 species in North America and around 1,500 species worldwide. They are most common near coasts and in wet wooded areas. Their young larvae live among moist decaying wood and roots, and the adults feed mostly on pollen and nectar from flowers.