A stonefly

[Fishigan 0]

I found a black stone fly under a rock when fishing today. I am not sure what kind it is. The stream is in south west Michigan and the stonefly measures 1 3/4" long from head to tip of tails. This does not count the antennae. The tails are about a 1/4" long maybe a little shorter. The only insect book I have is an orvis stream side guide "Trout Stream Insects" and I can find nothing that describes one of this size. This is the first stonefly I have found on this stream that is this big. I do not know much entomology at this point. Can ya tell?

[mrchbrwn 0]

Check out JasonN's site TroutNut.com it's a great site. Just look up stoneflys and start looking at pictures. I'm sure you'll find it or something close.

 

Rick

[Guest]

Fred, remember I told oyu about having that giant salmonfly land on my at that place? I bet that is the nymph. IT was a black stone with orange on it.

 

john

 

[Guest]

John I heard from Steve that it one of the crazy flying monkeys that landed on your arm, not a stonefly

[Guest]

It twas a flying monkey, you have too watch them, they fling poo!

[Fishigan 0]

I checked that site out. I can't find any reference as far as length. If I where to tie it I would say it would be a size 4 or 6. The body is a 1/4" wide.

[MbCarp 0]

from the sound of it - pteronarcys dorsata- they tend towards a dark brown olive- black/dark brown colour and are shorter tailed then some of the other large stonenfly nymphs- and they get bigger than that:)))))))))- they have a 3 year cycle egg- adult( spending the time as nymphs) - so you will find many sizes of them in a river- you may also find instar - very pale specimens- having freshly shed their nymph skin as they grow- trout love them:)))))))))))) there is also - try a google search- hope that helps

[Fishigan 0]

After doing alot of surfing and reading the closest thing I could find was this...

Scientific Name: Pteronarcys californica

[flyman 0]

Fishigan.

I'd say the Pteronarcys genius of stoneflies is a pretty good guess. I'm not so sure about the species though. The californica species is mainly a western species of stonefly. It's more than likley some other species of Pteronarcys, like the dorsata MbCarp mentioned. Identifying insects to the species level can be tricky. Even expert entomologist need to examine the bug under magnification for very subtle differences. Most times being able to identify an insect to the genus level is close enough. Take a look at this link with the distribution of stonefly genus and species in the US.

 

 

http://www.npwrc.usgs.gov/resource/distr/i...fly/usa/546.htm

[Taxon 0]

QUOTE (Fishigan @ Sep 24 2004, 05:26 AM)

I checked that site out. I can't find any reference as far as length. If I where to tie it I would say it would be a size 4 or 6. The body is a 1/4" wide.

Fishigan-

 

Mature Pteronarcys dorsata nymphs range from 38-63 mm. in length, measured from front of head to back of abdomen, excluding tails. I believe your specimen measured 1.5 inches, which is approximately 38 mm.

[nightfish 0]

The pteronarcys californica has a tusk (for lack of a better descrption) on either side of it's front wingcase, projecting toward the antennae and slightly to the sides. The pteronarcella badia has the same projections, but they are more rounded. I'm not familiar with P. dorsata.

 

Was the body fat & round, or more flat in profile?

[Fishigan 0]

more flat.

[Airhead 0]

I'm not sure to the species level, but that is the eastern equiv. of a Salmonfly. I have seen adults on at least 5 streams in Mi. Ussually around the 4th of july, I've never seen enough for the fish to be keying on them however. Just the occasional adult flapping about aimlessly.