Strangalia / Leptura sp.
Interesting looking bug, didn't realize there were two of them until I downloaded the photo on my iPad.
Looks like a mimic of this oil beetle, which is syntopic:
usually associated with floodplains, edges of temporary ponds.
Adults have chemical defenses, ejecting toxic, foul-smelling gases from their abdomen with a loud popping sound. The explosive brew is composed of hydrogen peroxide, hydroquinone, and catalytic enzymes.(BugGuide)
The Coleoptera /koʊliːˈɒptərə/ order of insects is commonly called beetles. The word "coleoptera" is from the Greek κολεός, koleos, meaning "sheath"; and πτερόν, pteron, meaning "wing", thus "sheathed wing", because most beetles have two pairs of wings, the front pair, the "elytra", being hardened and thickened into a sheath-like, or shell-like, protection for the rear pair, and for the rear part of the beetle's body. The superficial consistency of most beetles' morphology, in particular their possession...