Caddisfly larva - Ptilostomis

Moved

… tom murray, 16 February, 2009 - 10:35pm

another guess

Three guesses so far, Agrypnia, Phryganea, and Oligostomis. Like Tim said, a couple ventral shots of coxa and prosternum would help. I'll add another to the pot - Ptilostomis. Can't really see if the case is spiral or not.

Oligostomis has obvious mesonotal sclerites which are not present in your photos. Phryganea has a dark central frontoclypeal stripe. For me the tossup is between Agrypnia and Ptilostomis. Of all the Agrypnia I have seen, and the descriptions have available, there is a central frotoclypeal stripe like Phryganea, and/or the anterior dark pronotal stripe is right on the pronotal margin. And the lateral head stripes of Agrynia all seem to be outside the frontoclypeal suture. Ptilostomis is the only one left that I can make fit the photos and it is generally a larger critter than Agrypnia.

Don can figure it out.

… druiter, 16 February, 2009 - 8:04pm

More images added

I added a ventral shot, and one showing the whole case which looks like a hollow piece of a cattail stem. I caught over a dozen of these and one other species that uses the same type of case. The cases mostly measured 30-35mm, and the larvae were 25mm average.

… tom murray, 16 February, 2009 - 9:20pm

that helps

good photos - case is made of rings rather than a spiral. I will stick with Ptilostomis. Case length doesn't help much with caddis as most descriptions are of the animal length. And it really doesn't help much with phryganeids as they often drag around very long cases before they cut them off. I have a Ptilostomis with a larval length of 24mm and the case length is 56m.

I suspect you can't get a good picture of the foreleg coxal combs but Don should be able to see them with the scope.

… druiter, 16 February, 2009 - 10:25pm

Yes

Ptilostomis. Mixed in with several Phryganea, and three Agrypnia, which Tom somehow missed photographing. In looking at these I noticed in Wiggins' book that Agrypnia vestita is distinct in lacking the medial dark stripe on the head, but the case of this guy is correct for Ptilostomis (spiral in Agrypnia and of smaller pieces of material), and the color pattern of the head and pronotum is correct.

… Donald S. Chandler, 4 March, 2009 - 3:38pm

Tim

Thanks for the help. I'm saving it for Don Chandler, and maybe it'll be identified to genus or better.

… tom murray, 16 February, 2009 - 8:11am

Keys to...Phryganeidae

It's either Agrypnia or Phryganea but can't decide without view of ventral surface..I'm not very experienced with these so will leave it to the caddisfly experts...

… Tim Loh, 15 February, 2009 - 11:59pm