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3. caddis

caught in riffle about 2 cm long any ideas on what genus it might be

Dryfly-

It appears that the larval case is flattened on the bottom, as opposed to being cylindrical. Is that true? It also appears that the case is made entirely of plant material, as opposed having rock particles incorporated in its construction. Is that true?

taxon
it is under water so that is why it appears to be flat.
it is cylindrical

the case it made primarily with fine pieces of rock with some sticks toward the back
this may help I collected it in se minnesota

Roger, I was also deceived by the optical illusion caused by the water.

Dryfly, if you could extract the larva from the case without damage and rephotograph it, the identification should be easier. Perhaps Roger, Konchu, or David would then be better equipped to nail it down with the additional information that would be provided.

Dryfly-

The only family of caddisflies (of which I am aware), which builds stout, cylindrical, not gradually tapered or curved cases, made mainly or entirely of rock fragments, and would also be as large as your specimen is Limnephilidae.

The following Limnephilidae species reside in Minnesota:

Frenesia missa
Limnephilus indivisus
Limnephilus sericeus
Limnephilus submonilifer
Pycnopsyche guttifera
Pycnopsyche lepida
Pycnopsyche scabripennis
Platycentropus radiatus
Onocosmoecus unicolor
Hesperophylax designatus
Hydatophylax argus

Of those, only Fresnia missa (Dot-Winged Sedge), and Hesperophylax designatus (Silver Stripe Sedge) build cases resembling those of your specimen. Fresnia missa only reaches a length of 13.5 mm, whereas Hesperophylax designatus reaches a length of 20 mm., so that’s what my guess would be.

Really nice deductive reasoning, Roger!

Thanks, Gonzo. However, there is (at least) one caddisfly specialist who frequents this site, so I'm kind of waiting for "the other foot" to fall!

I know what you mean, Roger, but I still think it was an impressive application of both logic and resources. :)

thanks taxon and gonzo for your quick replies
I appreciate it
i'll post pics of the larva out of the case later today