Currently viewing the category: "Horntails, Wood Wasps and Sawflies"

don’t know what this bug is – can you help?
I took the attached pictures on Wednesday, July 20th. When I found this bug it was just sitting on something. I didn’t see it move at all. It has wings but I didn’t see it fly. In the picture, you can see someone’s thumbnail for scale reference. I live in Burlington, Vermont if that helps to identify the bug. I haven’t ever seen anything like this before. thanks

Hi Devon,
This is a Smoky Horntail, Genus Urocerus. They are found in mixed and coniferous forests mostly in the west, but a few species are found in the east. Adults drink nectar and larvae eat wood by tunneling through the sap and heartwood.

Update: Urocerus albicornus
(08/03/2007) Corrections on some ID’s
Dear Bugman,
Today I found a very eye-catching specimen of Urocerus Albicornis, the White-horned Horntail, wandering around on a Douglas Fir in extreme NW Washington State (near Ferndale) and laying eggs. I didn’t know what it was, but I captured it in a very high-tech device (empty paper soda cup courtesy of Burger King!) and brought it home, and after doing a little web-research, found out that it was the critter mentioned above. Actually, it was your website that really helped me make the leap forward finally – I wasn’t getting very far on any of the other so-called “identification” sites. So anyway, after I verified what it was, I tried to get some more information about it, but there doesn’t appear to be very much other than a very very few pictures. Almost NO information to speak of online. However, in the course of my ferreting around I finally came back to your site, and found several other pictures of this very dapper bug. But it looks like they are mis-identified, so I wanted to let you know. In response to the posting by Devon on 7/22/05, you state that it is a “Smoky Horntail,” and in response to a posting on 7/28/07 by Peter, it was ID’d as a “Wood Wasp…might be Urocerus Albicornis.” There were also several other postings that look very much like this bug, only the wings are more rust-colored – these are ID’d as Urocerus Californicus. (9/12/06 by Annie and one other, I don’t remember the date/poster though). I do have to apologize for not taking a picture of it for you guys before I released it, it was a real beauty. I’m glad I didn’t kill it though. … Also, must say, GREAT SITE!!!! Totally fascinating, to say the least. I spent WAY more time browsing around looking at all the cool bugs than the time I needed to find out about the Horntails. Two thumbs up!
Sean in Ferndale, Washington

Horntail or not?
My mother and her friend at work, caught this after much hysteria (apparently) thinking it was a wasp. We’re in Norfolk in the UK and it looks like, on your site, someone else has found one in the same area. It is about 3 – 4 inches long. Is it a Horntail? I’ve looked around the web and the pictures I’ve found of Horntails have different coloured eyes and abdomens to this, although they share a lot of other similarities. Also any idea whether it would sting? Thanks in advance!
Stuart Millins

Hi Stuart,
This is virtually identical to the insect we received two days ago that we identified as a Horntail. One of our American Species, the Pigeon Horntail, Tremex columba, looks very similar except for the coloration. They do not sting. The female uses the stingerlike ovipositor to deposit eggs under the bark of trees where the young larvae bore into the wood. A websearch of Tremex and Britain might turn up a photo. Please let us know.

Ed. Note: Additional searching turned up information on the Great Wood Wasp, Uroceras gigas as well as this illustration, which seems to positively identify this British Horntail.

What is this?
Dear WTB,
please help me identify this bug, we live in Norfolk in the UK and it landed in our garden, on a hot sunny day this July. The only thing I have found that is similar is a ‘Hornet Robber Fly’ but it has a different body and yellow eyes. > I look forward to hearing what you think it might be!
Matthew Johnson

Hi Matthew,
We are unfamiliar with the English species, but this bears an uncanny resemblance to a Horntail, a type of wasplike insect in the Family Siricidae. They have cylindrical bodies with the thorax and abdomen broadly joined together, not separated by a waist. In females there is a stinger like ovipositor which is used to drill into stems or wood where eggs are laid. Adults feed on nectar.

what is it?
WHAT IS THIS???!!!….I heard a buzzing in the trees and found this bug. It was so big and lethargic that it could not fly. I would say it was at least 2 inches long. It moved very slowly and it looked like it was dying. When it was still on the leaf it’s whole body would expand and contract..very yucky..I live in BC Canada..this is the second time I have seen a bug like this in my yard. I did a search on wasps and flys, but I couldn’t find anything that resembled this. Hope you can help!!

Hi Jen,
We consulted with Eric Eaton to try to get a species name for you, but he arrived at the same generalization we did. This is a Cimbex Sawfly. These are non-stinging relatives of wasps. The larva feed on the leaves of trees, especially willow. Sawflies can be recognized by their club-shaped antennae.

Mystery Bug
Can you identify this bug for me, please? Looks like a stonefly, but the head seems to large, the prothorax to small, and no tails. I’m really stumped!

Hi Roger,
We wanted to be sure, so we contacted Eric Eaton. Here is what he has to say: "The image you sent is actually of a sawfly, but I see the resemblance [to a stonefly]! Without knowing more information, I can’t even tell you which sawfly family this belongs in. However, this is the time of year when sawflies are in greatest abundance here in the U.S. and in Canada.
Sawflies are related to ants, bees and wasps, belonging to the order Hymenoptera. Larva of most species feed on foilage. They do not sting.

Cicada Killer? Photos included
We saw this wasp in Vermont on a camping trip in August 2004. It appeared on a large rock. For whatever reason, it did not fly. It was very slow moving, and it stayed in the same spot for a few days. "Cicada Killer" is the first thing that came to mind, but when i got home and looked on the internet I could not find a matching photo. This specimen has white markings, not yellow. It’s thorax and head are black, not brownish. And the legs and antennae are yellow and black. This was the largest wasp/hornet i’ve ever seen. I would say it was close to 2 inches. Can you shed some light as to it’s identity? Thank you for your time.
– Mike V.

Hi Mike,
We wrote to Eric Eaton and he just responded: “My chief suspect is a cimbicid sawfly, Cimbex americana, family Cimbicidae. Behavior fits, as they are slow-moving. They can approach an inch in size, but do not sting. Can bite, though.” Two inches seems rather large and possibly not entirely accurate.