These beetles are best looked at and not touched. They are common and easily found, some years there seems to be more of them, than other years. In the past two years I've not seen populations of them anywhere near like what I had two summers ago.
1.) Ash-Gray Blister Beetle
2.) Black Blister Beetle
3.) Striped Blister Beetle (picture by: Steve Scott) This is the variety that blistered me, and from what I've read this species contains higher concentrations of cantharidin than the other two species pictured here.