JOHNW on Jul 26, 2007July 26th, 2007, 10:40 am EDT
OK so here is a specimen I collected about 5yrs ago on the Falling Spring. We usually see a few scattered duns and spinners mixed with sulphurs (invarias I think). That year these things hatched en masse.
Best ID I've gotten was a Yellow Drake so I'll turn it over to you all.
"old habits are hard to kill once you have gray in your beard" -Old Red Barn
GONZO on Jul 26, 2007July 26th, 2007, 11:50 am EDT
Yeah, that is a little strange, but I have heard of YDs emerging on a much earlier schedule on some other streams. I don't think they were in PA, though. I'll try to track one of those examples down for you, John.
GONZO on Jul 26, 2007July 26th, 2007, 12:47 pm EDT
John, Knopp's Mayflies has an emergence chart for Connecticut that shows the YDs emerging mostly through May. This is in contrast to most of the other Eastern/Midwestern charts that reflect the more typical June/July period. I don't know what causes these differences, but they don't seem to reflect the usual north/south variations, and even elevation changes would not explain the difference in timing you see from one local stream to another. Perhaps Konchu has some insight into this.