Unknown - Zygogramma - BugGuide.Net

Prob. Zygogramma sp. -- det. E.G. Riley

[thanks for keeping the photo in the guide! =v=]

Moved from Leaf Beetles.

… v belov, 16 November, 2010 - 11:35am

Moved

Moved from ID Request.
A third vote for leaf beetle. As far as I know, sawfly larvae (or prepupae) all spin their cocoons before becoming short and stubby like this, assuming they do become short and stubby like this. They don't all pupate underground, but I think they do all pupate in cocoons.

… Charley Eiseman, 31 January, 2010 - 11:52am

leaf beetle

Thank you Charley for finally figuring out what to do with this. Should I leave it on BG or Frass it? Do you think it really adds anything or is just in the way?

… Carol Wolf, 31 January, 2010 - 4:12pm

Don't frass!

Many times things like this get IDed years later and sometimes they turn out to be very valuable. Keep it.

… Beatriz Moisset, 31 January, 2010 - 4:31pm

Don't frass!

Thanks Beatriz for your input. We will leave it.

… Carol Wolf, 31 January, 2010 - 4:36pm

I vote for Leaf beetle, too.

The "anchoring silk threads" I think are bristles of the plant. Also I never saw a sawfly pupa, I guess because the pupate underground.

… Boris Büche, 31 December, 2009 - 9:09am

plant bristles

The Ambrosia artemisiifolia link that I provided below displays a photo that shows hairs on the upper surface of the leaf, especially near the stem (when magnifying the high-resolution version). I just searched for other images on the Internet and found this one that displays even more hairs of this nature (the highly magnified version viewable by clicking twice on the image).

… John Pearson, 31 December, 2009 - 9:38am

Pre-pupal sawfly?

I'm thinking this might be a pre-pupal sawfly larva. The silk threads anchoring it are a clue. Leaf beetle larvae do not spin silk.

… Eric R. Eaton, 30 December, 2009 - 11:39am

Leaf beetle silk

Here's a chrysomelid that spins a cocoon--not suggesting that that's what we have here though.

… Charley Eiseman, 31 January, 2010 - 12:06pm

Pre-pupal sawfly?

Nice to meet you Eric. Thanks for your help with this one. Can these be identified to species?

… Carol Wolf, 30 December, 2009 - 11:58am

Raising it

It is too late to suggest that you try to raise it. If you find similar ones on the same plant you could try next year. I doubt it that it could be IDed from this photo alone. I am raising a few from my rose bush. I decapitate the roses, Morticia style, and keep the stems and leaves by the window with my green hairy pets chomping away until they decide to pupate. Then, I have to wait until next year because they need to hibernate.
Another pupa here
For ID purposes it would help to know the plant.

… Beatriz Moisset, 30 December, 2009 - 1:22pm

Plant...

...looks like Small Ragweed (Ambrosia artemisiifolia).

… John Pearson, 30 December, 2009 - 1:45pm

Leaf Beetle Larva ?

It reminds me of leaf beetle larva I've seen in the past.

… Andrew Williams, 30 December, 2009 - 9:35am