Currently viewing the category: "Horntails, Wood Wasps and Sawflies"
What's That Bug? does not endorse extermination

Subject:  Not sure what this is
Geographic location of the bug:  Fishhawk Falls, Oregon
Date: 08/26/2018
Time: 07:42 AM EDT
Your letter to the bugman:  Hi, I’m a photographer.  I spotted this little guy the other day and thought it was some kind of caterpillar but, it doesn’t match anything I’ve seen in the area.  as far as I know Its a larva to some bug .  Thank you for your time.
How you want your letter signed:  FilthyPerfection

Sawfly Larva

Dear FilthyPerfection,
Though it looks like a caterpillar, this is actually a Sawfly larva, and Sawflies are non-stinging relatives of bees and wasps.  Based on this BugGuide image and this BugGuide image, we are confident it is
Trichiosoma triangulum.  According to BugGuide:  “Larvae feed on leaves of alders (Alnus), ash (Fraxinus), poplars (Populus), willows (Salix), cherries (Prunus).”

What's That Bug? does not endorse extermination

Subject:  Caterpillar ID
Geographic location of the bug:  North Georgia, USA
Date: 08/11/2018
Time: 12:01 PM EDT
Your letter to the bugman:  Please help ID this caterpillar. I know it’s not monarch. It is boring into wood.
How you want your letter signed:  Dave Paulison

Carpenter Moth Caterpillar

Dear Dave,
We are feeling very confident this is a Carpenter Moth Caterpillar in the family Cossidae because of its resemblance to this South African relative, tentatively identified as
Macrocassus toluminus, though there are no matching images posted to BugGuide where it states:  “Larvae are wood-boring.”  But for the color, it also looks very much like both this posting from our archives and a this posting in our archives which we now believe are also Carpenter Moth larvae in the family Cossidae, but we are uncertain of the species.  Breeding Butterflies has an interesting article on the European Goat Moth, Cossus cossus, another species in the family, and the site states:  “The larvae of this moth do not feed on the leaves of the host plant – instead they bore tunnels though the wood, and live internally inside their host trees. Because of this habit, they are considered a harmful species; most caterpillars defoliate plants by consuming all their leaves. While definitely not beneficial for the health of the host plant, most plants and trees are able to recover from being defoliated. Burrowing directly through the trunks of trees is another story however, and is generally not the type of damage that trees can recover from. Because of this, a few larvae have the potential to kill even larger trees. And because their host plants include trees of economic value such as apple, cherry, walnut or olive, most farmers do not consider them welcome guests.”  We hope we can eventually provide a species identification for all three of our postings that all originate from Georgia and Florida.

Carpenter Moth Caterpillar

Correction:  Sawfly Larva
Thanks to Cesar Crash from Insetologia in a comment with a link to Oregon State University, we concur that this appears to be a Dogwood Sawfly Larva, Macremphytus lovetii.  The site states:  “The larvae leave the dogwood to pupate and will burrow into soft wood, and possibly soil, so house siding near a plant may be pitted with pupating chambers. Further damage may occur to structures from woodpeckers seeking to feed on the overwintering insects.”  Though BugGuide does not report the species from Georgia, it is reported from many eastern states, including North Carolina.

What's That Bug? does not endorse extermination

Subject:  wasp
Geographic location of the bug:  Wheatland, Wyoming
Date: 08/07/2018
Time: 02:39 PM EDT
Your letter to the bugman:  What’s this bug?
How you want your letter signed:  Roger Lockwood

Male Horntail

Dear Roger,
This is a male Horntail in the genus
Urocerus, which we identified thanks to this BugGuide image, and there is a comment attributed to Dave Smith on that posting that states:  “Urocerus sp., male. Could be either U. albicornis or U. flavicornis. The males are difficult to separate.”  Horntails are sometimes called Wood Wasps, but they do not sting, and no male wasps are capable of stinging anyways.  Here is an image from our archives of the female Urocerus albicornis and here is an image of the female Urocerus flavicornis.  The ovipositor of the female is used to lay eggs beneath the bark of conifer trees and its appearance is responsible for the common name Horntail.

What's That Bug? does not endorse extermination

Subject:  a flying insect , black with red on bottom
Geographic location of the bug:  Luzerne county, PA
Date: 08/05/2018
Time: 05:02 PM EDT
Your letter to the bugman:  I never saw this insect before.  It resembles a wasp and looks like it has a stinger on it’s end, the abdomen is a bright red , has wings and the rest of it black.
How you want your letter signed:  Dan

Black and Red Horntail

Dear Dan,
The only other image we have on our site of a Black and Red Horntail,
Urocerus cressoni, looks amazingly like your image.  According to BugGuide:  “hosts include Fir, Spruce, and Pine (Abies, Picea, Pinus).”

Thank you. Definitely looks like the picture you sent.


What's That Bug? does not endorse extermination

Subject:  Identification assistance sought
Geographic location of the bug:  My Ashland, OR ~6000 ft above sea level
Date: 06/27/2018
Time: 03:06 AM EDT
Your letter to the bugman:  I am guessing it’s a mitis fly but I couldn’t find one that looks exactly like it
How you want your letter signed:  Susan

Elm Sawfly

Dear Susan,
This is an Elm Sawfly, a non-stinging relative of Wasps and Bees.

What's That Bug? does not endorse extermination

Subject:  What is this
Geographic location of the bug:  Handworth middlesex
Date: 06/27/2018
Time: 07:52 PM EDT
Your letter to the bugman:  Can you identify this it was on my rose not seen one before
How you want your letter signed:  Wayne

Large Rose Sawfly

Dear Wayne,
This is a Large Rose Sawfly,
Arge pagana.  Sawflies are non-stinging relatives of Bees and Wasps that have larvae that are frequently confused for caterpillars.  According to Garden Safari:  “The Large Rose Sawfly is a quite beautiful and shiny animal. The animal is entirely black, except for the abdomen which is yellowish orange. Because of the dark, blackish wings, which are kept over the abdomen, the orange colour may not always be clearly visible. The legs are usually entirely black as well. The animals are not capable flyers, slowly flying about with the legs hanging down. In flight they are quite similar to to some flies, such as the St Mark’s Flies, appearing in spring as well. Males can be told apart from the females by looking at the antennae. Males have wire-like antennes, which are the same size just about everywhere. Females have antennae which get slighter thicker going upwards. The Large Rose Sawfly is on the wing in spring and early summer mainly. Depending on the temperatures most are seen from March to June. Like all Sawflies female Large Rose Sawflies are in possession of a little saw. With it they make rectangular cuts in the fresh shoots of the host plant. In the cut a bunch of eggs is being deposited. The larvae hatch quite quickly and move in a group to the freshly emerged leaves. Young larvae stay together for quite some time, capable of eating the entire shoot. Older larvae lead a more single life and eat from older leaves as well. The larvae are very similar to caterpillars and green with black dots and points. When they feel threatened they assume the so-called S-position. This can be seen in many other sawfly larvae as well. To pupate a firm whitish cocoon is spun near or in the soil. The cocoon actually has two covers. The inner one is smooth and firm. The outer cover has the design of a net. It is the pupa overwintering. The larvae are found on wild and cultivated roses. ”  According to iNaturalist:  “The larvae are gregarious and live in colonies feeding on rose leaves.”

Very interesting! How much damage can they do and all so I found a mint Beatle that was nice to look at and thank you for your answer kind regards Wayne

Hi again Wayne,
We have no personal experience with the Large Rose Sawfly, but from what we have read, the damage is done by the female laying eggs and by the larvae eating leaves.  A large infestation might defoliate a rose bush, but leaves will grow back.  A healthy rose bush should have no problem surviving a small infestation.

What's That Bug? does not endorse extermination