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.
119 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 subvaria (Hendrickson) Mayfly Dun
View 9 PicturesI collected this female Hendrickson dun and a male in the pool on the Beaverkill where the popular Hendrickson pattern was first created. She is descended from mayfly royalty.
View 9 PicturesI collected this female Hendrickson dun and a male in the pool on the Beaverkill where the popular Hendrickson pattern was first created. She is descended from mayfly royalty.Region: Catskills
Collected Apr 19, 2006
Added Apr 22, 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).
The mayfly and stonefly nymphs in this picture blend in extremely well.
In this picture: Insect Order Plecoptera (Stoneflies) and Mayfly Species Ephemerella invaria (Sulphur).
In this picture: Insect Order Plecoptera (Stoneflies) and Mayfly Species Ephemerella invaria (Sulphur).
Recent Discussions of Ephemerella
PMD Spinner - Egg sack color? 5 Replies »
Posted by Wbranch on Jan 26, 2010 in the species Ephemerella excrucians
Last reply on Jan 27, 2010 by Taxon
Do any of you entomologist types know the true color of the PMD spinner? Dorothea or excrucians. Where I fish in MT there are huge spinner falls, many spents are on the water in the morning and others fall again at various periods during the day. I'd like to tie some with egg sacks as I saw many in July but forgot what color they were. Thanks.
ReplyAw Shucks 10 Replies »Posted by Martinlf on May 19, 2009 in the species Ephemerella invaria
Last reply on Jul 24, 2009 by Martinlf
OK, this is going to seem like a major duh experience for some of you, but the other night I found a sulphur spinner on the door of a bathhouse in a campground I was staying at. Looking for other bugs I then saw a pale nymph shuck on the door. I was totally confused. A nymph this far from the stream? Was this some alien bug? Looking closer I noticed that the shape was too slender for a nymph and that the wing pads were more like little protruding pockets--and it hit me. Spinner shuck. I knew that mayflies molted to produce a spinner, but I had thought the shuck would be more insubstantial--something that would be flimsy and lack form. This was so cool, and at the same time I felt so silly for thinking it could somehow have been a nymph shuck. It's the first spinner shuck I've seen, but I assume that I'll start seeing them everywhere now, like a new word you learn. Anybody else have a spinner shuck story?
Replypmd hatches in ny? 3 Replies »Posted by Trouthunter on Apr 18, 2009
Last reply on Apr 19, 2009 by GONZO
I was recently told by a close friend of mine that in the southertier of ny ( finger lakes region) that we have very good hatches of pmds. I was hoping that someone could confirm this or otherwise before I tye up patterns. I have seen what I believe are sulphurs with slightly the same body and wing coloration but again thought that these couldn't be the famed insect.
Replypmd hatches in ny?Posted by Trouthunter on Apr 18, 2009
I was recently told by a close friend of mine that in the southertier of ny ( finger lakes region) that we have very good hatches of pmds. I was hoping that someone could confirm this or otherwise before I tye up patterns. I have seen what I believe are sulphurs with slightly the same body and wing coloration but again thought that these couldn't be the famed insect.
ReplyHatching HendricksonPosted by Martinlf on Oct 14, 2008 in the species Ephemerella subvaria
Here's another hatching mayfly, this one stillborn. Click on "31 more specimens" and scroll down.
ReplyThere are 7 more topics.
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