See Isonychia for details. It is the only North American genus in this family.
» Family Isonychiidae (Slate Drakes)
Pictures of 20 Mayfly Specimens in the Family Isonychiidae:
Isonychia bicolor (Mahogany Dun) Mayfly Nymph
View 7 PicturesThis Isonychia bicolor nymph from the Catskills displays the prominent white stripe sometimes characteristic of its species. This is the first such specimen I've photographed, because members of the same species in the Upper Midwest have a more subdued stripe (and were once thought to be a different species, Isonychia sadleri). The striking coloration on this eastern nymph is more appealing.
Recent Discussions of Isonychiidae
Isonichya Bicolor 21 Replies »
Posted by CraigK
on Mar 26, 2012
Last reply on Mar 29, 2012 by Entoman
I think the Iso. b. female was referred to a generation or so ago as the white gloved howdy. I love those old names. Too bad there are no pics of Potamanthus (golden drake). They may be extinct (siltation and acid rain?)...talked with Charlie Meck about that a few years ago. A beautiful mayfly...an important hatch of years past. I couldn't find any ref. to Epherons. An important hatch for me in about any area of the country. This my first post...love the site...very nice photog. Lets see what the strange weather of the year does to the hatches and fishing for this year. Overall, I expect it can't be good. CK ReplyAre Isonychia mayflies technically multibrooded? 4 Replies »
Last reply on Apr 17, 2009 by GONZO
ReplyPenns Creek Slate Draker's 4 Replies »
Here's what I've written in my article on Isonychia about their hatching:
Some Isonychia species are multibrooded, but not in the same way as most other multibrooded mayflies like the Baetidae. In those species, the flies emerging in midsummer or Fall are the offspring of the earlier hatch from the same year. In Isonychia, the Fall emergers are offspring from the previous Fall. They are present as half-grown nymphs when the first of their generation emerge. Although Isonychia broods have distinct peaks, some may be found on the water at any time in between.
I'm curious if they can really be called multibrooded or not, since they don't produce more than one generation per year (as far as I know). They simply have distinct populations within the same generation which emerge at different times during the year. Does that count?
All my books are packed up in boxes right now so I don't have a technical definition of the term handy.
Penns is one of the few places where a #10 iso will nail em' all year longReplyIso 1 Reply »
Great site, I'm an Iso. fanatic... JMReply
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