Last reply on Dec 18, 2013 by Brookyman
I wish I had been able to get a male spinner for a positive ID. I wasn't able to collect any, unfortunately. The keys I have to the adult genera of the Ephemerellidae require one.
I've placed several specimens collected from a similar emergence on nearby rivers into the species Attenella attenuata
, because they look exactly like the picture of that species in some books, most recently Ted Fauceglia's Mayflies
. They are handy midday and early evening emergers in northwest Wisconsin at a time when not much else is on the water. But I'm not convinced that the identification is correct.
For one thing, although I tried sampling several times in stretches where the duns were emerging, the only mature Ephemerellid nymphs I found keyed out to Ephemerella inermis
, which is now Ephemerella excrucians
. These adults fit the general description for that widely variable species. I never found any Attenella
I suspect they are the same species referred to in nearby parts of Wisconsin as "Kinni Sulphurs" and "Booger Sulphurs." As best I can tell from looking up those names, they seem to have been identified as Ephemerella inermis
but there is a local belief that they are Ephemerella needhami
, even though their color does not at all fit the description for that species.
Ah, to have a male spinner under the microscope...