West Branch Delaware nymph and Dun identification

[WTDoc]

I admittedly am not even a novice at entomology. I fished WB on Friday just above 191 Bridge in Hancock. Before i started, i turned over a few rocks and saw a few nymphs that i would like some help identifying. Unfortunately, i was not able to get a pic so, i was hoping a bit of a description may be suffice. The nymphs i saw were dark gray, slender long body thin tail with a very short thorax and head--the size was approximately the size of a 16 1-2xl hook shank. They were quite wiggly (scientific term...lol). Any clue? Also caught a dun (i think), dark gray/black segmented body with light dun upright wings and 2 long tails--probably size 16/18.

I was able to catch 4 small rainbows and 1 brownie (all 9-11 inches)--first 3 on size 18 flashback PT and the last 2 on a baetis perdigon. All caught in a shallow riffle 10-20 feet off the bank

 

[Nocktavius]

Sounds like a pheasant tail nymph to me 😜.

 

[Mike]

Don’t know the insect(s) based on your description.

 

[krayfish2]

ISO / slate drake nymphs

 

[Nocktavius]

ISO / slate drake nymphs

Figured they would’ve mentioned the pronounced white stripe if it was iso, but don’t have a ton to go off of here regardless

 

[krayfish2]

I heard short thorax, longer abdomen and wiggly.... rolled with that. This time of year what you should be seeing the second brood of ISO. Way too big to be a Hebe and doesn't sound like a late summer steno nymph. I was up there Tuesday - Wednesday and only stuff going on was sparse ISO, sparse olives, sparse Hebe and fair numbers of cinnamon caddis right at dark.

 

[sandflyx]

that small I would say grey drake, related to the slate drake, there are like 5 different iso species along the delaware water shed and streams

 

[sandflyx]

not all Iso nymphs have the stripe. Grey drakes dont have them