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

Subject: Cool bug
Location: Belton, Texas
March 29, 2013 8:01 pm
I found this bug on the rim of a red pot today. It wasn’t too afraid that I was close up to it. It feels like I have looked through every field guide of bugs native to our area and I still can’t find out what this is. Is it non-native? Thank you in advance!
Signature: Caleb J.

Elm Sawfly

Elm Sawfly

Hi Caleb,
This impressive creature is an Elm Sawfly,
Cimbex americana.  Sawflies are non-stinging relatives of Bees and Wasps, and they have larvae that are often confused for caterpillars.  This is a bit early in the season for an Elm Sawfly sighting, but that is not going to stop us from featuring your submission as the Bug of the Month for April.

What's That Bug? does not endorse extermination

Subject: A day of Freaky Flies
Location: Yarra Valley, Victoria, Australia
December 15, 2012 3:27 am
Hello Bugman, you’ve helped me before with a Bristle fly a couple of years ago. Today I’ve seen 3 strange flies on my cherry tree, which is currently being attacked by the cherry tree slug. I suspect they could be feeding on it, but I’m not sure.
It’s Summer here in Australia and today was a dull humid day.
Signature: Linda, Yarra Valley

Pergid Sawfly

Hi Daniel (again) this is the fly someone else thought might be a soldier fly although it looks very much like a wasp.  I was hoping with more photos you might have a better chance to identify it.
Linda from Healesville

Pergid Sawfly

Hi Linda,
Thanks for the additional images, but our opinion hasn’t changed.  We still believe this is a Chalcidid Wasp, a member of a family of Parasitic Hymenopterans, or some other Parasitic Wasp.  It will not harm your tree.  They parasitize other insects and according to BugGuide:  “hosts: mostly Lepidoptera and Diptera, though a few attack Hymenoptera, Coleoptera or Neuroptera(1). Parasites of Lepidoptera usually attack young pupae, while those of Diptera attack mature larvae.”  The Brisbane Insect website only has a few species pictured and none look exactly like your individual.

Correction:  Soldier Fly, not Chalcicid
Subject: Freaky Flyday Part 3
December 17, 2012 8:24 pm
This is NOT a hymenopteran esp Chacididae.  It is a Stratiomyidae.  look at wings and abdominal attachment and segments – beautiful mimic!!
Signature: Steve Schoenig

Thanks for the correction Steve.  We always appreciate input from experts.  We will write back to Linda to let her know she was right all along. 

Wow! thankyou for investigating it.  You’re still the expert in my eyes.
Linda from Healesville

April 7, 2014:  Alternate Identification:
We just received a comment from Mark Ridgway who believes this is a member of the family Pergidae, one of the Sawflies.  We may try contacting Eric Eaton on this posting.

Eric Eaton agrees with Sawfly
Had to do a little research on this one.  It is indeed a sawfly, family Pergidae.  Which genus, let alone species, I cannot easily assess.
Here’s a link to a website all about the family Pergidae:
Some females guard their young larvae, apparently.

What's That Bug? does not endorse extermination

Subject: unknown bug
Location: Southern Pennsylvania
October 13, 2012 6:19 pm
I had this bug, and was going to use it for an insect project due at school, but know one could figure out what it was. I thought it was a bee at first, but then I saw that it had two sets of wings. the head and thorax look good but the abdomen is crazy.
Signature: cary

Pigeon Horntail

Hi cary,
Normally we don’t respond to desperate pleas for assistance from students and their parents when they need identifications immediately, but your question has some very astute deductions.  This is a Pigeon Horntail, and it is in the same insect order as bees, Hymenoptera, which includes wasps and ants as well as sawflies, wood wasps and parasitoid Hymenoptera.  This female Pigeon Horntail is a Wood Wasp and she is a female.  She uses the stingerlike ovipositor at the end of her abdomen to deposit eggs into dead and dying hardwood.

What's That Bug? does not endorse extermination

Subject: Pine grub of some sort
Location: western NC
October 11, 2012 7:05 pm
Hello! I found these little fellows munching on a lil pine tree…. Have since collected them and sent them out in the woods, to munch on pines a bit further away from the house. (or for other animals to munch on, perhaps)
I am assuming they’re grubs, because they don’t have feet all the way down like ’pillers do…just a few at the front and a couple at the back end.
I realize bugs serve a purpose, but I’m wondering…should I have squished these? I hate killing anything, even the harmful bugs. ;)
Signature: not a bug hater

Possibly Pine Sawfly Larvae

Dear not a bug hater,
We cannot be certain because there is not enough detail in your photograph, but we believe these are Sawfly Larvae, possibly the Introduced Pine Sawfly,
Diprion similis, which you can find pictured on BugGuide.  Here is a remark from BugGuide:  “Introduced from Europe: first reported in North America in 1914, in Connecticut. Although a serious pest at times, it normally stunts rather than kills its hosts. It can be a more serious problem with young trees and in cases such as Christmas trees where appearance is important. It has natural enemies and diseases, so large outbreaks are only intermittently seen.”

What's That Bug? does not endorse extermination

Subject: HELP!!!
Location: Western Sydney Australia
September 28, 2012 4:26 pm
Hi Bugman, I found groups of these what appear to be caterpillars that seem to have fallen out of a tree onto a driveway at a group of factories – they seem to be working together to move across the driveway, but I’m concerned for their wellbeing, especially that they may be squished by a car…
Signature: Yo, Dumbo :)


Dear Yo, Dumbo,
Though they are often mistaken for caterpillars, these are the larvae of Sawflies, members of the insect order that contains wasps and bees.  In Australia, the larvae of Sawflies in the family Pergidae are commonly called Spitfires.  You can compare your photo to the ones posted on the Brisbane Insect website.

What's That Bug? does not endorse extermination

Subject: wasp in redwood
Location: Sonoma County, CA
September 23, 2012 10:25 pm
Howdy Bugman,
I run a small bandsaw mill unprofessionally and am current building a small house with it. I’m working on siding now out of a redwood that I dropped a year and a half ago and I kept running into these half pupated whatsits with creepy long legs. I thought they were Old House Borers but their legs looked too long for a beetles and also adding to the trouble was I kept beheading them with the saw which I’m sure you understand makes identification difficult. Finally uncovered this rather large metallic looking wasp that I miraculously missed with the saw. I dug it out and it sluggishly wandered around and I took a not so clear picture. I thought about killing it but if I spend a few minutes with an insect or arachnid even if they give me the heeby jeebies I feel bad and put them somewhere out of harms way. In this case I stuck it over on the scary old circular mill with removeable teeth. A little while later I saw it flying around and busily landing on things. Sin ce fall is fast approaching is this guy (gal?) going to make it or was it planning on overwintering in my siding?
Signature: best to all, Erik

Wood Wasp

Hi Erik,
This is some species of Wood Wasp or Horntail in the family Siricidae, and since you found it in redwood and redwood is a conifer, it is most likely in the subfamily Siricinae.  There are only two genera listed on BugGuide, and we are having a problem identifying this to the species level.  We will try sending the image to Eric Eaton to see if he can provide anything more specific.  Your letter was filled with helpful information on the habits of Wood Wasps and Horntails.
  We also located this very informative posting from the Bohart Museum of Entomology at UC Davis.

Eric Eaton Responds with some surprising news
This really is a great story.  Ok, from what I can gather, the only species of horntail known to infest redwoods in California is Sirex areolatus, and I reach that conclusion with the help of a very recent online reference:
Still, the ovipositor in this female specimen is very long.  I’d like to forward this e-mail to two of the authors of the above paper, whom I know from prior correspondence.  There is always the possibility I’m wrong, or that this is a new species, or an introduced species from elsewhere….
Lastly, with Erik’s permission, I’d like to use his image and story in a blog post about this species.  I’d need his last name to assign proper credit, of course.

Thank you so much for the identification I am fascinated by just about everything and enjoy learning more about my neck of the woods. Not actually my neck of the woods but I work there and that’s close enough. Just to be clear, I only thought about killing it because I was afraid it would generate future generations of wasps in my lumber. However upon reading that UC Davis article I understand they don’t infest or re-infest finished structures. This will learn me to get my butt in gear when I cut trees! Quite a spectacular wasp I’m glad I can say I didn’t kill it.
Thanks again,
Right, as for Eric’s request yes by all means. If it’s any more help, the larvae were found only in the sapwood of the redwood while the pupating ones and the adult were just in the surface of heartwood.
Best to all,
Erik Dolgushkin

What's That Bug? does not endorse extermination