Unknown Commensalistic Larva found in Oregon Oak Gall Wasp's (Besbicus mirabilis) gall

Eruciform larva in oak galls

I recently posted photos of two similar specimens which took from oak galls. They had 3 prs. thoracic legs and 4 pr. abdominal legs. Definitely caterpillar-like. Do you know their likely life-cycle or when/how they gained access to the gall chamber? Would they pupate in the gall?

… captom, 10 July, 2022 - 12:27pm

Eruciform larva in oak galls

The number of abdominal prolegs should've been stated as 5 pair, instead of four. Additionally, I have recently found caterpillars of in various stages of maturity inside gall chambers ranging in size from 8 mm long with white cuticles as in your photo, to 1.9 mm and 2.4 mm long with translucent cuticles. I have posted these in ID Request but without success. Please view them in my Images. I would love to correspond with anyone having an interest in the caterpillars of Oak Galls.

… captom, 7 November, 2022 - 7:59am

I don't think the answers to all of those questions are known,

but based on what I've seen so far, moth larvae that feed inside of cynipid galls exit before pupating, and likely overwinter as larvae or pupae. A little more information here.

… Charley Eiseman, 10 July, 2022 - 1:23pm

caterpillar inside oak gall

Your comment about moth larvae occupying oak galls is exciting because I also have had a chalcicidid (Hockeria sp.) emerge from a gall in May, 2022. I understand them to be a parasitoid of lepidoptera, which now makes sense. Also, the galls in which these larvae were found did have tunnels radiating out from the chamber. I posted a photo showing a larva in the chamber and it quickley retreated into one of the tunnels. My mysteries are being solved! Others have doubted my findings. That's for your help.

… captom, 11 July, 2022 - 10:19am

Moved

Moved from Butterflies and Moths.

… john and jane balaban, 29 March, 2014 - 3:28pm

Moved

Moved from Moths.

… john and jane balaban, 10 May, 2009 - 10:01am

Moth

I think this has to be a moth larva. Moving to the moth page for now...

… Charley Eiseman, 3 April, 2009 - 7:25pm

Moved

Moved from Besbicus.

… Beatriz Moisset, 13 January, 2009 - 7:03pm

size; location in gall

I assume 1-1.5cm is the size of the gall, not the larva? How large was the larva? Also, was this inside the small central chamber of the gall (see here -- the central chamber has the radiating fibers coming out of it), or was it in the gall but outside of the central chamber?

The larva doesn't quite look like a cynipid larva to me -- but I'm not so great with larvae. I've found lots of larvae that aren't cynipids inside galls, including in the larger, outer chambers of these galls. If it was in the larger chamber it's probably something other than a cynipid. I'll leave it to someone more expert than I am to decide what the larva is...

… Joyce Gross, 31 December, 2008 - 9:47pm

Hmm, I figured that this one

Hmm, I figured that this one was more mature than the others I found. This one was found in the large gall to the right and was in the outer shell. I'll upload one that I found in the center gall (bright colored one) that I peeled open it's little inner chamber.

… Mark Leppin, 31 December, 2008 - 10:44pm

the one you just loaded

is the cynipid. It's safe to move that to the species page -- not that it looks any different from most other cynipid larvae, but it does look like a cynipid and if it was in the central chamber then it should be Besbicus mirabilis. The other larva is something else taking advantage of a nice home. Hopefully someone else can tell us a bit more.

Probably the non-cynipid image should be unlinked from the other two, but then a comment and link added in the text under the image showing where the larva was found. The variety of life associated with oak galls is fascinating.

… Joyce Gross, 31 December, 2008 - 11:35pm

The other larva

I did the unlinking and comments with thumbs as you suggested. Now, where do we place this larva until it finds a home?
I was luckier with the goldenrod galls and two different inhabitants because I found lots of info on those.
See: Mordellistena. Those galls also can be complex ecosystems with several kinds of creatures. The gall maker is a fly, I found a fly larva and beetle larva and I know that there are at least two kinds of parasitic wasps that attack the fly larvae. Could the other larva be a beetle?

… Beatriz Moisset, 13 January, 2009 - 7:00pm

The other larva inside the gall

… Beatriz Moisset, 13 January, 2009 - 6:59pm

Clickable Guide

Calendar

Comment viewing options

Clickable Guide

Calendar

Comments

Comment viewing options