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> > caddis larva beh;a;vior question (really!)

The Specimen

Brachycentrus (Grannoms) Caddisfly PupaBrachycentrus (Grannoms) Caddisfly Pupa View 10 PicturesThe green blob contained in this case is a pupa in the early stages of transformation from larva to the final stage we generally picture and imitate. This specimen and several like it were fixed to a rock I picked up, and each one had the front of its case sealed off, protecting the helpless pupa from predation. It's neat to see the insect part-way through such a radical transformation.

It was very hard to extract this thing from its case, so there's a bit of extra goo near the head from where I accidentally punctured it.
Collected April 14, 2007 from Cayuta Creek in New York
Added to by on April 22, 2007

The Discussion

CaseyPDecember 18th, 2009, 1:37 pm
Arlington, VA/ Mercersburg, PA

Posts: 653
tying for the grannom hatch on the Little Juniata. have a couple of standards, but just can't resist fiddling a bit:

do the grannom larvae in their cases hold onto the rocks with little sticky filaments which might be duplicated with a few fibers of CDC, or do they hold on with their legs sticking out which can be duplicated with hackle, or do they not hold on at all?
"You can observe a lot by watching." Yogi Berra
TilmanDecember 18th, 2009, 4:01 pm

Posts: 37
Im interested in how you will attempt to imitate this kind of body.

Glass beads would do a good job, but are very heavy, if the size is too big. (i have some very small ones, for a size 14-16 nymph hook)

Id like to see a photo of your fly, when you are done.
"Live and Learn" - Mr. Spock
CaseyPDecember 18th, 2009, 4:38 pm
Arlington, VA/ Mercersburg, PA

Posts: 653
it's not fancy or intricate--peacock Ice Dub for a body, bright green thread, and a black tungsten bead. i've caught fish on size 12 nymph hooks and size 16 wet hooks.

i'll post a photo over on the photo place after the holidays.

i've tied them in Krienik braid as well, but haven't fished them; one of my gurus said the fuzzy, buggy one would do better. next spring i'll do one of my patented tests: tie one of each on a leader with two tags and see what works best. did that once with shad darts and indeed, that silly one with the plain red cone head out-caught the the others by a mile.
"You can observe a lot by watching." Yogi Berra
CrenoDecember 18th, 2009, 8:07 pm
Grants Pass, OR

Posts: 305
Brachycentrus larvae usually glue the leading edge of the case to the substrate of choice - rock, wood, another Brachycentrus case,etc. There are some great photos of this, and lots of other neat critters and stuff, on Joe Giersch's site: check it out! Joe is a great guy who knows an awful lot about alot of aquatic insects.

CaseyPDecember 19th, 2009, 6:45 am
Arlington, VA/ Mercersburg, PA

Posts: 653
gee, thanks, Creno! indeed, pictures are worth so much more than mere words...
"You can observe a lot by watching." Yogi Berra
LastchanceDecember 19th, 2009, 7:27 am
Portage, PA

Posts: 437
After looking again at Jason's photos of the grannom caddis, I wonder, don't we tie these pupas too dark? I know the emergers are tied with dark bodies imitated with peacock herl, etc.
LittleJDecember 19th, 2009, 1:25 pm
Hollidaysburg Pa

Posts: 251
I believe when they emerge from the case they are a darker color. However, a Tapered pheasant tail case w/ a light green sparkle yarn "larva" works great in the days leading up to this hatch.
CaseyPDecember 19th, 2009, 5:09 pm
Arlington, VA/ Mercersburg, PA

Posts: 653
I know the emergers are tied with dark bodies imitated with peacock herl, etc.--Bruce

well, silly me! all along i thought the peacock/furnace fly was imitating the cased larva come adrift in the process of pupating. hence my addition of bright green thread.
"You can observe a lot by watching." Yogi Berra
LastchanceDecember 20th, 2009, 7:01 am
Portage, PA

Posts: 437
Hi CaseyP: I may be wrong about that, but when I was learning to fly fish about 25 years ago that's what I was told. I fished a similar wet fly we called "Bait" because during the caddis hatch it caught so many fish on the deadrift and the swing. It was actually brown hackle and peacock.
Merry Christmas,
CaseyPDecember 20th, 2009, 12:11 pm
Arlington, VA/ Mercersburg, PA

Posts: 653
Bruce, you must be right: the adults are black with tan speckled wings. the pupa we see in Jason's photos was still inside the case. it stands to reason that the pupa would be darker when it was ready to hatch into an adult. (but what has reason to do with any of this?)

if we just let the trout tell us what color things ought to be, we'd save a lot of speculation, and it seems to me you've done that. thanks for sharing! back to the tying table...;-)
"You can observe a lot by watching." Yogi Berra
LittleJDecember 20th, 2009, 1:51 pm
Hollidaysburg Pa

Posts: 251
a peacock wet with a green tag works very well. The females are divers and the egg sac is about the color of the larva.

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