November 20, 2009
I found these 2 handsome beetles while digging in the garden in NE massachusetts in early november; I think they were a couple of inches down. I thought they were dead, and placed them in a container for later ID, and when I came back to them a few hours later, they were climbing all over to get out. So, I photographed them, and released them back into the garden. Are they a male and female, and what are they?
Linda in Mass.
These are Oil Beetles in the genus Meloe. Oil Beetles are Blister Beetles and they should be handled with care as they exude a compound that may blister skin. They do appear to be a pair, with the female being the larger of the two individuals. These are really great photos.
It is the first of December, and we hadn’t prepared in advance for a Bug of the Month, so we searched through recent postings and arrived at this lovely pair of Oil Beetles that was submitted last week. Oil Beetles can be found throughout North America, though our sightings from the east are more common. It may be getting a bit late in the year in New England, but they will still be active in the southern portions of their range. According to Bugguide, the antennae of the smaller males are modified as this set of photos indicates. The Oil Beetles release an oily substance that contains cantharidin which can cause blistering in skin, hence the common name of Oil Beetle. This trait is shared with many other Blister Beetles in the family Meloidae, including the notorious European Spanish Fly.