Oil Beetle

Subject:  What is this?
Geographic location of the bug:  Central NJ (Edison)
Date: 11/26/2017
Time: 02:30 PM EDT
I saw this creature as I was taking a walk. It was fairly large in size – about 1 1/2 to 2 inches in size. I saw it just now right after Thanksgiving. I did a reverse image search. Google proclaimed it a stag beetle. Bing returned a lot of pages from Japan. The shapes and colors are correct, but the wings are too small. The two wings on this picture are tiny stubs. Beetles have full wings that cover the abdomen. Hornets have transparent wings.
How you want your letter signed:  David W.

Oil Beetle

Dear David,
Your claim that “Beetles have full wings that cover the abdomen” is true in most but not all cases.  This is an Oil Beetle, a species of Blister Beetle in the genus Meloe.  Oil Beetles are flightless.  There are other species of Blister Beetles with vestigial wings like this Spanish individual, and many species of Rove Beetles like the Devil’s Coach Horse also appear wingless, though their wings are described on BugGuide as “elytra short (about same length as pronotum, or only slightly longer; wings are functional in most), typically exposing 3-6 (usually 5-6) abdominal segments.”

Thank you for your reply. I was beginning to wonder if this was an invasive species.
I did an image search on Bing (Google said it was a stag beetle) and it pointed me to a bunch of Japanese pages (in Japanese, of course) with pictures of very similar looking bugs. One site (via Bing translate) identified it as a “miyamatsuchihanmjou” which wasn’t much help, but there was a note attached calling it a type of blister beetle and warning me not to touch it. (Not that I had any desire to do so).
I guess the Japanese maybe more attuned to nature, but seeing all of these Japanese pictures and none in America, I feared it was an invasive species.
I see that these live in my area of New Jersey and are mainly active in the spring.
Again, thank you for the quick ID.
David Weintraub

Hi again David,
North America also has Oil Beetles that are active in the fall.

Yes. I saw they’re active all year. By the way, this specimen was between 1 1/2 to 2 inches in length – much larger than the ones you have posing by the quarter. I was hoping to have a quarter or some object to put in the picture in order to judge its size, but didn’t have anything. I also resisted the urge to pick it up and move it somewhere with better contrast. I’m glad I did.
I found one species called a “short winged oil beetle”. This specimen was about the size of the one I saw and was also found in New Jersey during freezing weather. https://bugguide.net/node/view/37966
I see the larvae live in flowers, hitch a ride on a passing bee, and live in the hive eating honey, pollen, and bee larvae.
David Weintraub

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