Mayfly Genus Ephemerella (Hendricksons, Sulphurs, PMDs)
Taxonomic Navigation -?-
Kingdom Animalia (Animals)
» Phylum Arthropoda (Arthropods)
» Class Insecta (Insects)
» Order Ephemeroptera (Mayflies)
» Family Ephemerellidae (Hendricksons, Sulphurs, PMDs, BWOs)
» Genus Ephemerella (Hendricksons, Sulphurs, PMDs)
11 species aren't included.
Common Name
| Match | Common Name |
 | Hendricksons, Sulphurs, PMDs |
There is a lot of variation between the species; read about each one for the details.
Where & When
Ephemerella nymphs inhabit all types of water. This genus is most important in the East and Midwest, where the major species hatch in the spring and a few continue into the summer. In the West, the other closely related genus Drunella takes on greater importance, but the Pale Morning Duns of Ephemerella are still important in the summer.Spinner Behavior
The concentrated evening spinner falls of many species in this genus are some of the best fly fishing events of the spring.They are also one of the groups of mayflies most prone to the unfortunate behavior of mating and ovipositing over blacktop roads hundreds of yards from the river.
123 Mayfly Specimens in the Genus Ephemerella:
Ephemerella subvaria (Hendrickson) Mayfly Dun
View 9 PicturesI collected this male Hendrickson dun and a female in the pool on the Beaverkill where the popular Hendrickson pattern was first created. He is descended from mayfly royalty.
View 9 PicturesI collected this male Hendrickson dun and a female in the pool on the Beaverkill where the popular Hendrickson pattern was first created. He is descended from mayfly royalty.Region: Catskills
Collected Apr 19, 2006
Added Apr 22, 2006
Ephemerella subvaria (Hendrickson) Mayfly Spinner
View 11 PicturesI collected this beautiful male Hendrickson specimen as a dun, along with a female Hendrickson from the same hatch. Both molted into spinners in my house within a couple of days.
View 11 PicturesI collected this beautiful male Hendrickson specimen as a dun, along with a female Hendrickson from the same hatch. Both molted into spinners in my house within a couple of days.Region: Northeast
Collected Apr 23, 2007
Added Apr 25, 2007
Ephemerella needhami (Little Dark Hendrickson) Mayfly Spinner
View 12 Pictures
View 12 PicturesRegion: Upper Midwest
Collected Jun 4, 2005
Added May 25, 2006
6 Streamside Pictures of Ephemerella Mayflies:
View Full Size
Here's an above-the-water view of a stillborn (Stillborn: In fly fishing, a stillborn insect is one which got stuck in its nymphal or pupal shuck during emergence and floats helplessly on the surface instead of flying away. It is a specific class of cripple, although it is sometimes used interchangeably with that term.) Ephemerella subvaria dun which I also photographed from below the water.
In this picture: Mayfly Species Ephemerella subvaria (Hendrickson).
View Full Size
In this picture: Mayfly Species Ephemerella subvaria (Hendrickson).
This Ephemerella invaria sulphur dun got stuck in its shuck (
Shuck: The shed exoskeleton left over when an insect molts into its next stage or instar. Most often it describes the last nymphal or pupal skin exited during emergence into a winged adult.) trying to emerge. This isn't exactly a "natural" pose for a photograph, but it kind of shows what an emerger pattern could look like.
In this picture: Mayfly Species Ephemerella invaria (Sulphur).
Here's an underwater view of the pupal shucks of several already-emerged Brachycentrus numerosus caddisflies.
In this picture: Mayfly Species Ephemerella invaria (Sulphur).
37 Underwater Pictures of Ephemerella Mayflies:
This Ephemerella subvaria (Hendrickson) nymph picture is one of my favorites.
In this picture: Mayfly Species Ephemerella subvaria (Hendrickson).
In this picture: Mayfly Species Ephemerella subvaria (Hendrickson).
There's a large Ephemerella subvaria nymph in the top left.
In this picture: Insect Order Trichoptera (Caddisflies), Mayfly Species Ephemerella invaria (Sulphur), and Mayfly Species Ephemerella subvaria (Hendrickson).
In this picture: Insect Order Trichoptera (Caddisflies), Mayfly Species Ephemerella invaria (Sulphur), and Mayfly Species Ephemerella subvaria (Hendrickson).
Recent Discussions of Ephemerella
Wow, they really can take forever to get off the water 32 Replies »
Posted by Troutnut on Jun 14, 2006 in the species Ephemerella dorothea
Last reply on Aug 15, 2007 by Wiflyfisher
I watched quite a few of these guys emerge tonight. (I think -- they seemed too small and light to be Ephemerella invaria, though I didn't bring one home to check under the microscope.) It was a cool evening but not cold, and they were emerging on the slow flats of a large midwestern spring creek. I watched several of them drift 50+ feet on the very slow-moving water, slowly rising up out of the surface film. Their emergence was sporadic and lucky for them the trout were also sporadic. Many were eaten but others went ignored for their entire lengthy drifts.
Later in the evening I was bested by a half-dozen rising trout. The sulphurs were still emerging, and a mix of spinners was starting to appear on the water, but I didn't get so much as a splashy refusal from several rising fish, even in the low light of dusk. My best guess is that they were picky feeders keying on a stage of Ephemerella dorothea mayflies.
ReplyAnyone know more about Ephemerella septentrionalis? 4 Replies »Later in the evening I was bested by a half-dozen rising trout. The sulphurs were still emerging, and a mix of spinners was starting to appear on the water, but I didn't get so much as a splashy refusal from several rising fish, even in the low light of dusk. My best guess is that they were picky feeders keying on a stage of Ephemerella dorothea mayflies.
Posted by Troutnut on May 18, 2007 in the species Ephemerella septentrionalis
Last reply on Jun 18, 2007 by Konchu
I found about one sentence on these in Gonzo's book, and haven't seen them mentioned anywhere else in fly fishing literature. Nor is any of the scientific literature I have on them particularly interesting (just descriptions). Now that I've collected a few and see what unique-looking nymphs they've got, I'm really curious about them.
ReplyWhen does a Hatch happen? 8 Replies »Posted by TheMidge on May 10, 2007 in the species Ephemerella subvaria
Last reply on May 26, 2007 by Greenghost
I was hoping I could get a little info on what effects a Hatch. Air Temp? Water Temp? A combination? I'm trying to determine the best time to catch a hatch on stream near me, as I have a small window to fish in on a short trip home. I am expecting to see Hendrickson's, as it's the right time of year (or so I have been told) for this stream. What's the best way to guess?
Replyunderwater photos 4 Replies »Posted by Martinlf on Dec 26, 2006 in the species Ephemerella subvaria
Last reply on Apr 21, 2007 by PeterO
Jason, thanks for the underwater photos of subvaria nymphs and the stillborn dun. Anyone looking at this thread may have to search for them a bit, (click on "There are 29 more specimens") but they are well worth the viewing! They have given me a better understanding of how to modify my upside down mayfly tie to better represent still born and crippled subvarias, and the underwater nymph pictures have confirmed my thoughts about coloration on flies designed to imitate subvaria nymphs. The photos are phenomenal, not like any bug photos I've seen before, in that they show the insects in a natural habitat.
ReplyThere is 1 more topic.
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