Watch Out for Blister Beetles

It's that time of year again... 

The blister beetles are doing their dance to make more blister beetles, and I suggest we all put on our old shoes and stomp until they are all flat and dead! You can ID them by their flat head, long bodies and legs, and thread-like or beaded antennae. Here are photos of species we see most often around Paulden, in Yavapai County, Arizona.

 

Every horse owner should know what they look like because it  just takes a few in a flake of hay to cause a horse to suffer digestive and urinary tract damage, inner hemorrhages and even death if they are unlucky enough to ingest too many. The beetles are capable of synthesizing cantharidin, one of the most poisonous compounds known to humans AND this chemical causes terrible blisters on the skin (see last photo).

The last (sorry it's gross) photo is when one got to me while I was cleaning out an old shed in NM. I never even knew I rubbed against its body until later. I had seen the beetles in the shed and did not recognize the species. The blister lasted 3-4 months and the doc felt it was at risk of infection if she lanced, so I kept it clean, bandaged, covered with a pants leg.

Beautiful bugs aren't always beneficial. This one is not one of my favorites.