Currently viewing the category: "Blister Beetles"
What's That Bug? does not endorse extermination

Subject: Looks like ants
Location: Huntsville, AL
December 12, 2015 8:43 am
We found this large ant-like bug inside the house near the back door. I thought it might be a queen due to its huge size (approx 25 mm). A few days later, however, we found another smaller one on the bathroom floor. I figured the odds of finding two queens was pretty slim, so now I’m stumped. I’m hoping they’re not carpenter ants, because they don’t seem to match any of the descriptions I’ve seen online.
Signature: Keith

Oil Beetle

Oil Beetle

Dear Keith,
This is not a queen Ant, though many of our readers mistake Oil Beetles for queen Ants.  Oil Beetles are Blister Beetles in the genus
Meloe, and they should not be handled as they secrete a compound cantharidin that may cause blistering in human skin.

Daniel,
Thanks for the info.  I was about to pick it up and toss it outside, because I thought it was just a ground beetle at first.  Once I got close to it and saw it wasn’t, I thought twice about picking it up.  I’m glad I didn’t!
Keith

What's That Bug? does not endorse extermination

Subject: Odd bug in the park
Location: Southern Ontario, Canada
December 20, 2015 5:53 am
Dear bug man,
We saw this large insect while walking to school last week, and got our mother to take a picture. It was about two cm long. It was a warm day in December.
Signature: Bug-watching sisters

Oil Beetle

Oil Beetle

Dear Bug-watching Sisters
This is an Oil Beetle, a species of Blister Beetle in the genus
Meloe.

What's That Bug? does not endorse extermination

Subject: Gravid Queen Carpenter Ant?
Location: Wythe County, southwest VA, USA
December 7, 2015 9:36 pm
I’m not sure of the ID of this insect. I’m guessing it is a Carpenter Ant–a gravid queen–but I’m not sure. My son has been replacing a section of our roof here in southwest VA. He discovered this insect today on a rotten board that he had removed and had thrown to the ground. It was cold, so it was hardly moving, which made it easy to photograph. Thank you for any help in ID!
Signature: Carolyn

Oil Beetle

Oil Beetle

Dear Carolyn,
Many people mistake Oil Beetles, the flightless Blister Beetle in your image, for queen ants.

Thank you so very much!  This is the first time I’ve seen one!  Love your website!

What's That Bug? does not endorse extermination

Subject: Weird Beetle
Location: Frederick, MD
November 27, 2015 8:44 am
I saw this bug when I took my dogs out. Was wondering if it was a threat to them!
Signature: Molly

Oil Beetle

Oil Beetle

Dear Molly,
This is an Oil Beetle in the genus
Meloe, a member of the Blister Beetle family.  Blister Beetles are capable of secreting a compound cantharidin that is known to cause blistering in human skin.  This Oil Beetle is not concerned with attacking or threatening your dogs, but if one of your dogs was to attempt to try to eat one, your dog might encounter some irritation or possibly even a more severe reaction.

What's That Bug? does not endorse extermination

Subject: Halloween Oil Beetle Orgy
Location: New Haven, CT
November 17, 2015 7:54 pm
This group of oil beetles was having a party in one corner of a lawn in a residential New Haven, Connecticut neighborhood on the morning of October 31. They were all within a one-foot square and there were none anywhere else around.
Thanks to all the hours I’ve spent on your site, I knew exactly what they were! I had never seen any in person before.
The cell phone photos came out pretty well so I thought I’d contribute them for your archives.
Signature: Tom

Mating Oil Beetles

Mating Oil Beetles

Dear Tom,
You images of mating Oil Beetles from the genus
Meloe are a wonderful addition to our archives. It would be curious to know what about the small area where you found them caused the Oil Beetles to congregate so amorously.  According to BugGuide:  “In males of some species mid-antennal segments are modified, and the c-shaped ‘kinks’ involving antennomeres V–VII are used to grasp female antennae during pre-mating displays.”  The individual featured alone in your one image has these modified antennae, hence is a male.

Male Oil Beetle

Male Oil Beetle

What's That Bug? does not endorse extermination

Subject: American Oil Beetle?
Location: Hamilton Ontario
October 24, 2015 9:41 pm
Hello Bugman,
I’ve got another find for you! I think this is an American Oil Beetle, but it seems a good deal larger than the description I read. This guy was hanging out inside our museum for a day or two before I rescued him. He looked dull black indoors but once I got him out in the sunshine I could see he had a beautiful greenish sheen on him. Didn’t know what his preferred host plant was, so I hope he found something to eat! (& a warm place to hide!)
Signature: Alison

Oil Beetle

Oil Beetle

Dear Alison,
We don’t mean to alarm you, but you should exercise caution when handling any of the Blister Beetles in the family Meloidae as members of the family secrete a compound called cantharidin that is known to cause blistering in human skin.  Regarding Oil Beetles in the genus
Meloe, according to the University of Connecticut Home & Garden Education Center page:  “The adults feed on grass and  several leafy weeds and flowers. ”  Though The Smaller Majority site has a fascinating overview of the life cycle of the Oil Beetle, nothing is mentioned about adult food preferences.

Yikes! Thanks for letting me know. I’m glad she was in a good enough mood that no one got hurt! Will exercise caution in the future when handling unknown insects. Thank you for your time!
Alison Innes

What's That Bug? does not endorse extermination