Blister beetle

Blister beetles produce cantharidin, which is toxic to people and animals. This toxin is rapidly absorbed from the gastrointestinal tract and excreted in the urine. Cantharidin is the poisonous substance in blister beetles and is thought to protect the beetles from predation. It is comparable to cyanide and strychnine in toxicity . The toxin is found in the hemolymph and gonads of the blister beetle. The content of cantharidin in the beetles ranges from 1-5% of dry weight.
Cantharidin is present in all stages of blister beetle . Cantharidin is produced only by male blister beetles and is stored until mating. The male beetle biosynthesizes about 17 mg of the toxin, representing 10% of his live weight . Male beetles have the highest levels of the toxin and transfer cantharidin to the females during copulation.