Subject: wasp in redwood
Location: Sonoma County, CA
September 23, 2012 10:25 pm
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
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.
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,