The oil beetle (or Meloe) is a blister beetle genus. They are called "oil beetles" because they release oily droplets of hemolymph when disturbed.
Oil beetle from Wiener Prater
The liquid is a poisonous chemical that causes skin blistering and painful swelling.
Members of this genus do not have wings. They have shortened elytra.
- ↑ "Oil Beetles". BugGuide. Retrieved Feb. 20, 2017. CS1 maint: discouraged parameter (link)