following Bugguide.net this is most like E. callosa but for now will leave it to genus.
This large beetle landed on our porch shortly before the severe thunderstorm hit this afternoon.
Insecto que estaba solo parado en la hoja, muy quieto sin presentar molestia por la camara
I think M. angusticollis is the nearest match.
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.