I observed three of these guys, while visiting the Marsh-Billings-Rockefeller park near Quechee, VT. They were a little over an inch long, glistening blue, and immediately caught my eye. Looking like big fat ants, they drudged along through the grass looking depressed or drugged. Their stubby wing-pads (they are flightless) barely noticeable over their bloated abdomens. I thought they resembled the dresses that used to be in style… a long time ago:
Reading online, I learn they are in the family Meloidae and get their name from the fact that they ooze an oily substance from their leg joints when disturbed. Also, are apparently parasitic as larvae! First, a female oil beetle will lay up to 1000 eggs (?@#$%). When the eggs hatch, the larvae will climb up onto flowers and attach themselves to solitary bees. They hitch hike back to the burrow, where they relax and feed on the bees pollen and eggs. When it pupates, the adult oil beetle will continue to reside in the safety and warmth of the burrow through the winter until spring arrives. Jeez! Talk about a your uninvited, intrusive guests!
Here’s a video from this youtube user of oil beetles in action. Even a hungover oil beetle at 1:56.