Currently viewing the category: "Horntails, Wood Wasps and Sawflies"
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Subject: Swarms of wood chewing bugs
Location: grand rapids, michigan
April 12, 2014 4:35 pm
At first glance I thought “carpenter ants,” but that’s only because we have a massive carpenter ant issue in our neighborhood. Upon taking a closer look, I realized that they were definitely not carpenter ants. They come in swarms of 20-50 and land on any exposed wood in the area. At first it seemed that they were just congregating, but I noticed that the totem pole I’d been carving was starting to look smoother… Like someone had come around and sanded it for me. Since Wednesday of last week I’d noticed that the entire pole was covered in these things, but was too busy with other things to look closer. Today I went out and got a good look, and it was pretty clear that their mandibles were working extra hard. They were gorging away. I’ve had no luck identifying them on my own, and more than anything I’m just really curious what they are. They don’t seem to come from any particular direction, one minute there’s none , and five minutes later there’s dozens of them. They aren’t the best flyers, and seem to land in the grass every few feet before launching off again.
Signature: dave

Sawfly Chews Wood!!!  But Why???

Sawfly Chews Wood!!! But Why???

Hi Dave,
We wanted to contact Eric Eaton to get his opinion on this perplexing behavior prior to assembling the posting.  Chewing wood is generally a behavior associated with paper wasps and hornets that use the wood pulp in the construction of a nest.  The numbers of wasps you observed coming to your totem pole at the same time also implies that this is some type of social wasp, but it resembles a Wood Wasp more than a social wasp.  Here is what Eric Eaton wrote back.

Dolerus Sawfly chews wood, but why???

Dolerus Sawfly chews wood, but why???

Eric Eaton provided an identification, but cannot explain behavior
Daniel:
Ok, I can identify the wasps, but cannot explain the behavior….
The wasps are sawflies in the genus Dolerus (pretty sure anyway, definitely sawflies).  I’ll ask around and see if anyone can explain them flocking to a wood carving.
Eric

Sawfly attracted to wood shavings.

Sawfly attracted to wood shavings.

Update:  Thanks to Eric Eaton’s identification, we were able to locate an image of a Dolerus Sawfly on BugGuide that does indeed resemble the Sawflies in your images, and it is also crawling on some exposed wood.  There is no explanation regarding what is going on in these BugGuide images, nor in this BugGuide image.  This Cirrus Image website provides some information, including “Their flight is slow and clumsy, resembling that of a common firefly. Larvae feed on various grasses.”  But alas, there is no information on wood chewing activities.

Thanks for the identification!  Its quite odd, they definitely match the description, especially the clumsy flight.  On that note they certainly don’t fly together, they arrive one at a time within a minute or two of each other.  I had to take down some tree limbs today and sure enough the cut ends of the limbs were crawling with these guys within a few minutes.  The odd thing is they don’t interact with each other at all.  In fact it really looks like they are just sitting there.  If you get really close however, you can see their mandibles are hard at work.  They don’t really leave any marks, it seems that they just clean off any small dangling bits of wood.  Yesterday I noticed one had its abdomen curled down in an awkward position as though it was a bee trying to sting the wood.  But I haven’t seen any others do that.  But its like they can smell fresh cut wood for miles, because you won’t see them all day, but cut a log and they’re everywhere.
Thanks again!  You’ve definitely satisfied my curiosity, even if their behavior leaves a new mystery to solve.
Dave

What's That Bug? does not endorse extermination

Subject: Never seen one like this.
Location: Mid Michigan USA
February 16, 2014 10:43 am
I have been finding these little bugs in our house. Only find one or two a week. I live in mid-michigan he have had a long hard winter. Not sure where the bugs are coming from. Maybe a table decoration that was made out of birch tree limbs. Just wondering what kind of big this is. It’s about the size of a dime In length.
Signature: Thank you, Chris

Stem Sawfly perhaps

Wood Wasp

Hi Chris,
We believe this is a Sawfly, a group of insects classified with bees, wasps and ants in the order Hymenoptera.  It shares some physical similarities to the Stem Sawfly in the genus
Janus that is pictured on BugGuide.  We will try to contact Eric Eaton to see if he shares our opinion.

Eric Eaton provides an identification
Daniel:
This is something much more interesting than a sawfly, but it is *related* to sawflies:  a xiphydriid wood wasp, no doubt this birch-boring species:
http://bugguide.net/node/view/310291
No records on Bugguide for Michigan yet, so would be nice to have Chris post this great image there.
Eric

What's That Bug? does not endorse extermination

Subject: orange caterpillar
Location: Lakeland, FL
February 10, 2014 12:53 pm
We found several of these crawling around on rocks. They’re very fast movers, but curl up if you touch them. They’re about 1 to 1 1/4″ long. We didn’t see them on any plants, just the rocks. We’re in Central Florida, inland and found them on 2/10/14. I’ve never seen anything like this before and after trudging through the interweb, don’t see any pics that match. As you can see in the 2nd fuzzy pic, they have black heads. He was on the move and hard to catch.
thanks for any help.
Signature: Cindy & Jim

Orange Larvae:  Caterpillars or Sawflies???

Orange Larvae: Caterpillars or Sawflies???

Dear Cindy & Jim,
We are very rushed this morning and our initial attempts at identification did not produce any results.  We are posting your photos as unidentified and we hope to return to this later when we have more time.  Meanwhile, perhaps one of our readers wants to take up the challenge.  We are not certain if these are caterpillars or Sawfly Larvae.

Sawfly Larva or Caterpillar???

Sawfly Larva or Caterpillar???

Thanks for your quick reply. We’ve never seen anything like it.

Considering your Florida location, this could easily be a new exotic import from a faraway land.

I was afraid of that. I feel like we should go hunt them down and hold on to them until we know what they are. We have too many exotics here.
thanks

What's That Bug? does not endorse extermination

Subject: Never seen this bug before
Location: Limpopo, hoedspruit (lowveld)
January 31, 2014 9:13 am
Hi, I saw this caterpillar in our garden and wonder if you could help to ID it.
Area: South Africa, Lowveld
near Hoedspruit, Limpopo
Season: summer 31 January 2014
Size: about 1.5 cm in length and 1 cm wide
I live in the Balule nature reserve thus it’s a wilderness area
Thank you
Signature: Laetitia

What's That Grub?

What’s That Grub?

Hi Laetitia,
This is not a Caterpillar, but we do believe it is a larval insect.  In our opinion, this is most likely a Beetle Grub, though we would not rule out that it might be a Sawfly Larva.  While your individual looks very different from the larvae in the links we provided, we wanted to show you some examples of possibly classifications.  Knowing the plant this larva was feeding upon might help with the identification.

What's That Grub???

What’s That Grub???

What's That Bug? does not endorse extermination

Subject: Caterpillar ID
Location: York Region Forest, Newmarket, Ontario, Canada
November 6, 2013 10:36 pm
Hello Bugman,
I would like to get some info on this caterpillar.
It was found in York Region forest, just half hours drive of Toronto, Ontario, Canada.
It was searching on old decaying tree trunks in the parking lot when I first spied it, during the middle of October 2013. A few days later, I found a second one (may be same one) in the same location.
I took both photos, of which you may use for display purposes.
I have been searching many butterfly and moth categories, without any luck in naming it. Maybe (I’m thinking) its a sawfly? Its about 1 1/2 to 2 inches in length.
I have just started a website and trying to name the species that I have included on it.
Thanks for any info…
Brian

Pine Sawfly Larva

Pine Sawfly Larva

Dear Brian,
Just because it looks like a caterpillar and acts like a caterpillar, does not necessarily mean it is a caterpillar.  You are correct that this is a Sawfly Larva.  It is an Introduced Pine Sawfly Larva,
Diprion similis, and according to BugGuide, it is an adventive species introduced from Europe.  BugGuide also notes:  “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.”

Introduced Pine Sawfly Larva

Introduced Pine Sawfly Larva

Dear Daniel,
Many thanks for your reply -to my request asking for identification,
regarding the bug that I had found – most informative. No wonder many of
the conifer trees in that area that it was found in, had issues with their
foliage etc.
Brian

What's That Bug? does not endorse extermination

Subject: Weird looking wasp!
Location: California/north american midwest
October 10, 2013 1:49 pm
I have no idea what this weird looking wasp type bug is hope you could help.
Signature: byron

Pigeon Horntail

Pigeon Horntail

Hi Byron,
Please clarify if this photo was taken in California or the North American Midwest.
  This appears to be a Pigeon Horntail, a species of Wood Wasp, but BugGuide’s data does not have any reports from California, however BugGuide states it is probably adventive in California.

What's That Bug? does not endorse extermination