Blister beetles are beetles (Coleoptera) of the family Meloidae, so called for their defensive secretion of a blistering agent, cantharidin. There are approximately 7,500 known species worldwide. Many are conspicuous and some aposematically colored, announcing their toxicity to would-be predators.
Cantharidin is a poisonous chemical that causes blistering of the skin. Cantharidin is used medically to remove warts and is collected for this purpose from species of the genera Mylabris and Lytta, especially Lytta vesicatoria, better known as "Spanish fly".
Blister beetles are hypermetamorphic, going through several larval stages, the first of which is typically a mobile triungulin. The larvae are insectivorous, mainly attacking bees, though a few feed on grasshopper eggs; while sometimes considered parasitoids, it appears that in general, the meloid larva consumes the immature host along with its provisions, and can often survive on the provisions alone, thus they are not obligatory parasitoids but rather food parasites that are facultatively parasitoid, or simply predatory. The adults sometimes feed on flowers and leaves of plants of such diverse families like Amaranthaceae, Asteraceae, Fabaceae, and Solanaceae.
The blister beetle genus Epicauta is highly toxic to horses. A few beetles consumed in a single feeding of alfalfa hay may be lethal. Poisonings have also been reported after use of "Spanish fly"-type folk medicines, and after handling blister beetle individuals. The toxic chemical is cantharidin.
Subfamily Eleticinae 
Subfamily Meloinae 
Genera incertae sedis
Subfamily Nemognathinae 
Genera incertae sedis
Subfamily Tetraonycinae 
See also 
|Wikimedia Commons has media related to: Meloidae|
|Wikispecies has information related to: Meloidae|
- Blister Beetle Intoxication: Cantharidin Poisoning
- blister beetles UF / IFAS Featured Creatures
- striped blister beetle, Epicauta vittata UF / IFAS Featured Creatures
- Beetle mania as 'extinct' insect found on Scots isle
- Ever so Strange: Blister Beetles
- Mylabris Pustulata Orange Blister Beetle found in Farms near Nagpur, Maharashtra, India