Tuesday, January 12, 2010

Sawfly - Birch Wood Wasp (Xiphydria mellipes)

We have discovered a refugee family trying to keep warm in our house. We're hoping that a certain blogger can help us at least generally identify the critter.

I am at a loss to even venture a guess, I'm not even sure if I can assure our concerned daughter that it doesn't bite. We have found 3 or 4 over the past few weeks, usually alone and somewhat docile but moving. Usually crawling slowly across the floor, the last guy attempted to fly but could not quite leave the ground (see action shot below).

Length estimated at 15 mm. Using only a 5-year-old point-and-shoot camera (I guess that's old in electronic years), I must say I'm surprised some of them sort of turned out.

UPDATE: This bug has been identified as a Wood Wasp (a type of Sawfly) by 'The Home Bug Gardener' and species confirmed by Robin Leech via Albertabugs via Henri Goulet: "This is a Xiphydriidae. The species is Xiphydria mellipes associated only with small (less than 3 inch) branches of dead birch." Thanks to everyone for their help!

The bug's home is clearly small diameter paper birch branches we cut last year and placed inside for use as coat/hat racks. The wood wasps are waking up confused and disoriented in their new interior habitat! I have confirmed online that wood wasps do not sting and do not pose a threat to structural wood in the house (I guess that assumes small diameter birch is not used for home construction in this case!).

I think this helps with our decision to keep at least some of our dying paper birch as a bug and bird sanctuary (I was debating chopping them down). I wonder who else is living in there??


Dave said...

Wow, what a very pretty sawfly you have in your basement!

At least that is what it looks like to me. Could be something rarer, but in any case it won't do any damage inside the home.

I should learn something about sawflies, especially since they can be interesting wildlife (and several of them are pests in the garden), but I am abysmally ignorant. I’ve posted your url at Albertabugs and maybe someone will come up with a good answer.

Dave said...

Here's a first guess on your sawfly, or in this case 'wood wasp' family Xiphydriidae.

This would be one of the good, wildlife kinds of sawflies that oviposit in dead trees where their larvae feed on fungi.

Your specimen doesn't have the white antennae of this picture:


but otherwise looks pretty similar to someone who doesn't know his sawflies.

Anonymous said...

Bugs in the basement? Some people have all the luck...

Queen of West Procrastination said...

Did I ever tell you guys about the strange bugs that were in my parents' basement for a while? They looked like small-ish grasshoppers, but they had one big hind leg and one small one, and so they'd hop sideways. You see one and you think it's just injured. And then you see several, over a year, and you realise you have some kind of weird mutation or something.

I wish we'd managed to photograph it.

Dave said...

Jason via Albertabugs agrees:

"I think this is a Xiphydria sp. (Xiphydriidae), they tend to have that distinct 'neck' and fairly cylindrical shape.

I used to get them emerging every now and then in winter from firewood.


Cassandra said...

I don't much care for the look of the bug, but that last photo is really good! My attempts at wildlife photography always turn out pretty dismal.

Dave said...

Here's a definitive identification of your basement sawfly via Albertabugs (thanks to Robin Leech) and the Canadian Government:

"This is a Xyphidriidae. The species is Xyphidria mellipes associated only with small (<3") branches of dead birch."

Henri Goulet
Research Scientist (Entomology) | Chercheur (entomologie)
Agriculture et Agroalimentaire Canada | Agriculture and Agri-Food Canada
960 Carling Av. | 960 Ave Carling
Ottawa, ON K1A 0C6

Middle Earth Garden said...

Incredible! Thanks so much for your help Dave and Robin.

Now here is some confirmation of the identification: I was just reading that individual wood wasp species are typically associated with very specific types of trees (i.e. often a wood wasp species feeds on a single species of tree).

Just before your post above I suddenly realized that the wood wasp was likely coming from birch branches we cut off our dying paper birch tree last summer and have been using in the house as coat/hat racks. The branches happen to be less than 3 inches in diameter... enough said!

This may become addictive. Although the point-and-shoot can sometimes take a decent close-up shot, it is really hit-and-miss (mostly misses). Some day I may have to upgrade my camera to help explore the amazing bug world around us. Any advice on economical camera models best suited to bug and plant closeups?

Adrian Thysse said...

See my post at:

Dirty Girl Gardening said...

I don't know but it reminds me of the doc series Under growth... yo should check it out on netflix. Very cool