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

Subject:  Are these Monarchs?
Geographic location of the bug:  gilford, nh
Date: 08/30/2017
Time: 02:49 PM EDT
Found this hatch a leaf between leaves in a patch of milkweed. They have the coloring of Monarch caterpillars, but I have never seen so many together. Do you know what they are?
How you want your letter signed:  Curious in NH, Wendy O.

Sawfly Larvae

Dear Wendy O.,
These look more like Sawfly Larvae to us.  Sawflies are non-stinging relatives of wasps and bees whose larvae resemble caterpillars.  Here is a BugGuide image of a Sawfly larva in a similar position, and here is a BugGuide image of a similar grouping of Sawfly Larvae.  Finally, here is a BugGuide image of a really similarly colored Sawfly Larva, but alas, it is not identified to the species level.  We are posting your image and perhaps one of our readers will be able to assist with a species identification.  Were they actually on Milkweed?

No, the leaves were intermingled with the milkweed plants which had sprouted up in our flower garden.  Thanks for letting me know. They looked so much like mini monarchs that I was confused.  I’m in the garden and outdoors a lot and had never encountered anything like these.  Thanks for responding so quickly.
Best regards,
Wendy O.

What's That Bug? does not endorse extermination

Subject: Unknown Bug
Location: Pembrokeshire
August 13, 2017 5:18 am
What is the bug shown in the attached photographs? It appeared from timber posts that were delivered this week. Apologies for only getting one photograph but it also had what I assume was a stinging needle approx 10mm long. I live in West Wales and have not seen one of these before.
Many Thanks,
Signature: Byron

Great Wood Wasp

Dear Byron,
We just finished posting an image of a Great Wood Wasp from Ireland.

What's That Bug? does not endorse extermination

Subject: What is this bug
Location: Co kerry ireland
August 13, 2017 11:35 am
Can you tell
Me what this isb
Signature: Michelle osullivan

Great Wood Wasp

Dear Michelle,
This is a Great Wood Wasp,
Uroceros gigas, and according to UK Safari:  “Great Wood Wasps are often mistaken for Hornets because they look similar to a wasp but considerably larger.  They’re sometimes called ‘Giant Horntails’ for obvious reasons.  The female Great Wood Wasp has a long pointed tube at the back of her body, and this is usually mistaken for a stinging organ.  In fact it’s an ovipositor, which she uses to lay her eggs in the trunks of coniferous trees.  Despite their slightly fearsome appearance, these insects are quite harmless.”

What's That Bug? does not endorse extermination

Subject: Unknown Horntail
Location: Washington
August 8, 2017 12:30 pm
I was moving some logs in my backyard I’m Mukilteo and came across this little guy. I captured it and then continue moving the logs. I found three more but the third one got away. One of the additional ones I got is all black while the other is just a bigger version of the first one. I know they are Horntail, research from this website but which kind?
Signature: Elizabeth


Dear Elizabeth,
Your Horntail is
Urocerus albicornis which you can verify by comparing your individual to this image posted to BugGuide.  According to BugGuide:  “hosts include fir, larch, spruce, pine, Douglas-fir, hemlock, and western red cedar.”

What's That Bug? does not endorse extermination

Subject: Unknown red caterpillar
Location: Southwest Ohio
August 6, 2017 8:08 pm
I found this red caterpillar today in a woods in SW Ohio. Andy idea what it is? I’m outside a lot and have never seen one before.
Signature: Terry

Sawfly Larva

Dear Terry,
Though it looks like a Caterpillar, this is actually a Sawfly larva and it will become a non-stinging adult Sawfly related to bees and wasps.  We believe your Sawfly larva is in the genus

Thank you!  I noticed the link you sent was from Caesar Creek Lake, about 40 miles from here.  I’m a biologist, but insects are not my strength, and I’ve never seen one of these before.

What's That Bug? does not endorse extermination

Subject: Huge flying wasp/hornet
Location: Québec
July 17, 2017 1:21 pm
Hey guys I saw this huge thing in a swampy area in the woods of western Canada (Québec ) I wanted to know what species it could be? Thanks guys.
Signature: Emil

Elm Sawfly

Dear Emil,
The Elm Sawfly is a non-stinging relative of wasps and hornets.

What's That Bug? does not endorse extermination