Currently viewing the category: "Sap Beetles"

Subject: Can I stop losing my mind?
Location: Brooklyn, NY
June 10, 2014 9:24 pm
I live in Brooklyn, with ever-present fear of bedbugs. Found this thing crawling on a shirt on top of a dresser today and about came unglued but later concluded it wasn’t a bedbug. It’s about 2.5-3mm long, and revealed wings only after it had flailed, stuck, upside down for a little bit in a small glass container I put it in to try to figure out what it was. I’ve put too much time into internet searches in my effort to identify this bug and thus figure out if I need to keep freaking out/do something. Any help you can provide with the ID would be much appreciated.
Signature: Evangeline

Unknown Beetle

Picnic Beetle

Dear Evangeline,
We don’t know anything about the loss of your mind, but if it is any consolation, it is our observation that a mind isn’t that important in the Third Millenium.  As you have already determined, this is not a Bed Bug, and it sure looks to us like a beetle because of the clubbed antennae and what appears to be mandibles.  We will do some research and attempt to identify your distinctive looking beetle soon.  We plan to step away from the computer and read through Arthur V. Evans new book:  
Beetles of Eastern North AmericaWe just had a curious thought, which we hope doesn’t put you over the edge, but we think this looks like a Carrion Beetle.

Unknown Beetle

Picnic Beetle

Carrion like dead meat? Am I dead meat?
Thanks–if it helps I can try to get a better photo of it now that it’s daytime and my daughter is not sleeping in the room with the real camera.
Freaky but interesting?
Thanks so much. Look forward (sort of?) to hearing back from you–
I did, btw, think it looked like some silphidae pictures last night but wasn’t sure, and I’m not cleaning any bones or anything around here, I promise!
It was crawling on a shirt my husband got free from a run in Central Park but that was last week and I thought he’d washed the shirt…?
Thanks again,

Unknown Beetle

Picnic Beetle

Good Morning Evangeline,
We believe we have identified your beetle as a Bark Gnawing Beetle, Peltis septentrionalis, thanks to Arthur V. Evans new book:   Beetles of Eastern North America, where it states:  “Adults found under bark of conifers in association with red banded (Fomitopsis pinicola) and brown staining cheese (Oligoporus fragilis) polypores.  Across Canada and northern United States;  in eastern North America south to New York and Minnesota;  Eurasia.”  Here is an image from BugGuide.  Your individual appears shinier, but other than that difference, which might be an illusion because of flash photography, we believe it is a good match.  So, we hope we didn’t alarm you with the Carrion Beetle speculation.

You all are awesome!!! The bug is a bit shiny but looks very much like the one linked.

Correction, courtesy of Karl:  June 12, 2014
Hi Daniel and Evangeline:
Close, but the carapace does not look right. I believe it is actually a Sap-feeding Beetle, probably a Six-spotted Sap-feeding Beetle, Prometopia sexmaculata (Nitidulidae: Nitidulinae). They are also known as Picnic Beetles. Regards. Karl

Subject: Bugs eating strawberries
Location: Zone 5 – New York
July 11, 2012 8:04 am
Can you tell me what kind of bug this is and how to keep it away from the strawberries?
Signature: -Roxy

Picnic Beetle

Hi Roxy,
This is a Fours Spotted Sap Beetle,
Glischrochilus quadrisignatus, and it goes by the other common names Picnic Beetle or Beer Beetle.  According to BugGuide it is:  “attracted by the odour of fermenting fruits and vegetables; the adult beetles fly into beer or soft drinks at summer picnics.”  The strawberry in the photo appears to be dirty as well as rotting.  We suspect something else might have done the initial damage.  Do you place straw on the ground around the strawberry plants?  That will help to discourage snails and slugs which love to eat strawberries.  If the strawberry in question was damaged by a slug and it then began to rot, that might have attracted the opportunistic Picnic Beetle.  If the Picnic Beetles are actually doing the initial damage, which we doubt, you can always leave a glass of beer in the area of the strawberry plants in the hope the beer will be more attractive to the Picnic Beetles than the strawberries.

Subject: I think this is a Silphidae
Location: Reese, MI
July 1, 2012 8:21 pm
I have an infestation of these bugs. By looking at the shell I think that these are from the Silphidae family. But all the information that I have found said that Silphidae do not bite but these do. They seem to come out at night and are attracted to apple cider vinager. Please help me identify these pests and come up with a way to keep them away from my deck!!!!
Thank you
Signature: Tireman2000

Four Spotted Sap Beetle

Dear Tireman2000,
Why ever do you keep a container of vinegar outside if it attracts these Four Spotted Sap Beetles which are also called Picnic Beetles or Beer Bugs.  We identified them first by doing a web search for vinegar beetles and we found a Sap Beetle on the Cape Beekeeping website.  The website author traps beetles in his bee hives by using mineral oil and cider vinegar, and he had a photo posted that was identified as a Sap Beetle that looked like your beetle.  Armed with that information, we found the Four Spotted Sap Beetle,
 Glischrochilus quadrisignatus, on BugGuide where it states they eat:  “various fermenting substances” and they are “attracted by the odour of fermenting fruits and vegetables; the adult beetles fly into beer or soft drinks at summer picnics.”  Again, please let us know what you are doing with the vinegar.

Vinegar attracts Sap Beetles


Elm Tree Bug
Location:  Eastern Colorado
September 22, 2010 2:26 pm
Dear Bugman,
I am searching for an identification for the group of bettles in the enclosed photo. They have gathered in a sap pocket of an American Elm Tree in Eastern Colorado.
Signature:  Daniel

Sap Feeding Beetles

Dear Daniel,
It is difficult to make out the details of the individuals in your photo, but we nonetheless believe they are Sap Feeding Beetles in the family Nitidulidae, possibly
Glischrochilus quadrisignatus, the 4-Spotted Sap Beetle which is pictured on BugGuide.

Thank you very much for the information!  That looks to be the correct match!  What a great service you offer!  I would recommend to anyone!
Very grateful,

the mysterious beer bug
Hi, Bugman!
I live in south-eastern Ontario, and during all of the summers of my childhood, our picnics were plagued by little black and white beetles about a quarter of an inch long that loved our food and would bite if you weren’t careful. Coming from a family of teetotalers, we called them “food bugs”. Later, I heard them called “beer bugs”, but I’ve not yet come across a person who knows what kind of beetle they actually are, and my web research has revealed no clues. Can you enlighten me? Thanks!
Jaimie Cowles

Hi Jaimie,
Our initial impression based on the shape and antennae, is that this is either a Sexton Beetle in the genus Nicrophorus, or some other Carrion Beetle in the family Silphidae. Sexton Beetles are characterized by red markings and we couldn’t find any matches on Bugguide. We are going to try to contact Eric Eaton, but we know he is having computer problems and may not respond for some time. Meanwhile, perhaps a reader can assist.

Update from Eric Eaton (08/04/2008)
The black beetle with the four yellow marks is a sap-feeding beetle in the family Nitidulidae. This one is probably Glischrochilus quadrisignatus, better known as a “picnic beetle.” They will sometimes fly to picnics in large numbers, attracted mostly by fermenting fruit, and probably alcohol, too. Not harmful in the least, just annoying:-)