Any of approximately 2,000 species of beetles (family Meloidae) that secrete an irritating substance, cantharidin, which is used medically as a topical skin irritant to remove warts.
In the past, cantharidin was often used to induce blisters, a common remedy for many ailments, and the dried remains of Spanish fly ( Lytta vesicatoria ) were a major ingredient in so-called love potions. Adult blister beetles, which are often brightly coloured, range between 0.1 and 0.8 in. (320 mm) in length. Blister beetles are both helpful and harmful to humans; the larvae eat grasshopper eggs, but the adults destroy crops.
Blister beetle ( Lytta magister ).
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