A blister beetle

 

On June 27th, while checking out a little native plant area at Duval Rd. and Amherst Dr., I noticed a Mexican hat (Ratibida columnifera) crowned with an orange beetle. Just as I was photographing it, it started to take off; fortunately my ring flash mostly stopped the motion. Curious about the name blister beetle after the folks at Bugguide.net told me that’s what the insect was, I found more information at their Meloidae page:

“Pressing, rubbing, or squashing blister beetles may cause them to exude hemolymph which contains the blistering compound cantharidin. Ingestion of blister beetles can be fatal. Eating blister beetles with hay may kill livestock. The three-striped blister beetle Epicauta occidentalis can especially be a problem for livestock as they get caught in with the alfalfa feed. Several other species in Epicauta and Meloe (M. laevis and M. niger) may be present in alfalfa as well. Cantharidin, commercially known as Spanish Fly, may be present in higher concentrations in some species of Epicauta than Meloe (Capinera et. al., 1985).

“Males of some other beetles (notably, Pedilus and some Anthicidae) seek out blister beetles, climb onto them and lick off the exuded cantharidin. These other beetles, resistant to the toxic effects, use the agent to impress their females; the cantharidin is transferred to the female with the sperm packet during mating. The eggs the female lays are coated with cantharidin to protect them from predators. Some plant bugs (e.g. Aoplonema) are also attracted to meloid beetles….”

 

© 2023 Steven Schwartzman