Large Mahogany Duns
This common name refers to only one species.
Mayfly Species Isonychia bicolor
These are sometimes called Large Mahogany Duns.
This is by far the most important species of Isonychia. Many angling books once split its credit with the species Isonychia sadleri and Isonychia harperi, but entomologists have since discovered that those are just variations of this abundant species.
See the main Isonychia page for more about these intriguing mayflies.
See the main Isonychia page for more about these intriguing mayflies.
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.
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.Region: Catskills
Collected Apr 19, 2006
Added Apr 21, 2006
Female Isonychia bicolor (Mahogany Dun) Mayfly Dun
View 13 Pictures
View 13 PicturesRegion: Upper Midwest
Collected Jun 14, 2005
Added May 26, 2006
Male Isonychia bicolor (Mahogany Dun) Mayfly Spinner
View 15 PicturesI got several really nice pictures of this spinner. I also collected a female on the same trip.
View 15 PicturesI got several really nice pictures of this spinner. I also collected a female on the same trip.Region: Northeast
Collected Aug 9, 2006
Added Aug 11, 2006
See 16 more specimens...
New features!
