The Stream Doctor

June 6th, 2005

Email YOUR Questions directly to the Stream Doctor. This is your opportunity to get an experts professional opinion on anything stream related.

Q. I had been fishing this week on spring creeks in western Wisconsin. I observed many mayflies(?) flying off the surface. These flies were not drying on the surface; they seemed to hatch and erupt immediately into flight. What might these be?

The tactic of using a nymph dropper on a parachute dry fly was incredibly successful at landing many, many brook trout.

Thanks for your help. Sincerely, T. Looze

A. I think you're asking a couple of questions: (1) are these mayflies?, and (2) what kind of mayflies are they?

As you probably know, mayflies have two stages in their adult form; a sub-imago that hatches from the final nymphal instar and the imago. The sub-imago is sexually immature and the duration of this stage can be as short as a few minutes or as long 24 to 48 hours. They do need some time to transform from one stage to the other.

Thus, if the insects that you were observing were literally flying off after emerging without spending at least a few minutes drying, then I'm guessing that they probably weren't mayflies.

Whether they were mayflies or some other order of insects, there's simply no way that I could identify them without more information and some specimens to observe.

I'm obviously hedging on a direct answer, but that's about the best I can do with the information you sent. Sorry.

Take care, ~ Bert

If you have a question, please feel free to contact me.
~ C. E. (Bert) Cushing, aka Streamdoctor
105 W. Cherokee Dr.
Estes Park, CO 80517
Phone: 970-577-1584

The 'Stream Doctor' is a retired professional stream ecologist and author, now living in the West and spending way too much time fly-fishing. You are invited to submit questions relating to anything stream related directly to him for use in this Q & A Feature at

If you would like to comment on this or any other article please feel free to post your views on the FAOL Bulletin Board!

Previous Stream Doctor Columns

[ HOME ]

[ Search ] [ Contact FAOL ] [ Media Kit ] © Notice