It's always fun when clients bring insects into the office to be identified. Although I'm pretty good at recognizing common pests, I'm not an entomologist. That makes it a little more work to figure out what I'm looking at.
This insect was recently brought in:
(Photo by Aaron Schusteff on BugGuide.net)
Usually I cringe when someone brings in a beetle because there are so many kinds; fortunately I was able to figure this one out! I've seen this insect out in the Tableland every year so I at least knew where it likes to live. I also recognized it as a blister beetle. The rest was just figuring out what I had from a greatly narrowed list of options.
This insect is Tegrodera latecincta, the iron cross blister beetle. It is found from Mono Lake to Antelope Valley in L.A. County. It has close relatives in nearby deserts.
Blister beetles have a defensive chemical called cantharidin that is pretty nasty stuff. It causes blisters to skin. It's not a good idea to handle blister beetles with your bare hands. Crushed up blister beetles can end up in hay, which can be dangerous to horses if eaten.
Apparently native species of Eriastrum are favored hosts of the adult beetle, but I'm sure I've seen it on other things. It is unknown what the immature stages eat. Maybe wasps or ants?
It's probably not a problem for your garden, but you never know if this will be on Jeopardy!