Mayfly Family Ephemerellidae (Hendricksons, Sulphurs, PMDs, BWOs)

Mayflies Caddisflies Stoneflies

Taxonomic Navigation -?-

Kingdom Animalia (Animals)

» Phylum Arthropoda (Arthropods)

» Class Insecta (Insects)

» Order Ephemeroptera (Mayflies)

» Family Ephemerellidae (Hendricksons, Sulphurs, PMDs, BWOs)

Genus in Ephemerellidae
Attenella	0	0
Caudatella	0	0
Dannella	0	0
DrunellaBlue-Winged Olives	0	0
EphemerellaHendricksons, Sulphurs, PMDs	0	37
EurylophellaChocolate Duns	0	0
Matriella	0	0
Penelomax	0	0
Serratella	0	0
TeloganopsisLittle black Quills	0	0
Timpanoga	0	0

3 genera

(Caurinella, Dentatella, Tsalia)

aren't included.

Common Name

Match	Common Name
	Hendricksons, Sulphurs, PMDs, BWOs

This is page 24 of specimens of Ephemerellidae. Visit the main Ephemerellidae page for:

• The behavior and habitat of Ephemerellidae.
• 37 underwater pictures of Ephemerellidae.

Pictures of 271 Mayfly Specimens in the Family Ephemerellidae:

Specimen Page:1...232425...28

Drunella grandis (Western Green Drake) Mayfly Nymph View 3 Pictures

Collected July 2, 2019 from the Gallatin River in Montana
Added to Troutnut.com by Troutnut on July 18, 2019

Male Ephemerella (Hendricksons, Sulphurs, PMDs) Mayfly Spinner View 3 Pictures

Collected May 26, 2007 from Penn's Creek in Pennsylvania
Added to Troutnut.com by Troutnut on June 4, 2007

Ephemerella (Hendricksons, Sulphurs, PMDs) Mayfly Nymph View 4 Pictures

Collected June 1, 2005 from the Bois Brule River in Wisconsin
Added to Troutnut.com by Troutnut on May 24, 2006

Male Ephemerella invaria (Sulphur Dun) Mayfly Dun View 3 Pictures

Collected May 29, 2004 from unknown in Wisconsin
Added to Troutnut.com by Troutnut on January 25, 2006

Female Ephemerellidae (Hendricksons, Sulphurs, PMDs, BWOs) Mayfly Dun View 6 Pictures

Collected July 31, 2020 from the Henry's Fork of the Snake River in Idaho
Added to Troutnut.com by Troutnut on August 17, 2020

Drunella coloradensis (Small Western Green Drake) Mayfly Nymph View 6 Pictures

Collected August 4, 2020 from Green Lake Outlet in Idaho
Added to Troutnut.com by Troutnut on August 20, 2020

Eurylophella (Chocolate Duns) Mayfly Nymph View 3 Pictures

Collected June 8, 2005 from the Namekagon River in Wisconsin
Added to Troutnut.com by Troutnut on May 26, 2006

Female Eurylophella (Chocolate Duns) Mayfly Dun View 3 Pictures

Collected June 4, 2005 from the Teal River in Wisconsin
Added to Troutnut.com by Troutnut on May 24, 2006

Ephemerella aurivillii Mayfly Nymph View 11 PicturesThis is a puzzling one to identify and I'm not sure about the species. The maxillary palp (

The palp on the maxilla of an Ephemerella nymph (detached and photographed under a microscope) is highlighted in red here.

Palp: A long, thin, often segmented appendage which can protrude from certain insect mouth parts such as the maxillae. Also known as the < />palpus.) is present and segmented, and the maxillary canines are not strongly serrate laterally. I think it's Ephemerella, not Serratella. The ventral (Ventral: Toward or on the bottom.) lamellae of the gills on abdominal segment 6 have a clear median notch with a depth at least half the length of the lamellae, which points toward a couple of uncommon species (most likely Ephemerella alleni), but the abdominal tubercles (

A few (not all) of the abdominal tubercles on this Ephemerella needhami nymph are circled. They are especially large in this species.

Tubercle: Various peculiar little bumps or projections on an insect. Their character is important for the identification of many kinds of insects, such as the nymphs of Ephemerellidae mayflies.) and coloration don't fit that species. To add to the confusion, none of the above species are expected to emerge in the fall, as far as I know. I'm going to call this one Ephemerella aurivillii for now, but that's highly uncertain.

Collected September 10, 2020 from the Foss River in Washington
Added to Troutnut.com by Troutnut on September 19, 2020

Female Ephemerellidae (Hendricksons, Sulphurs, PMDs, BWOs) Mayfly Spinner View 7 Pictures

Collected August 1, 2020 from Mystery Creek #237 in Montana
Added to Troutnut.com by Troutnut on August 18, 2020

Specimen Page:1...232425...28

Jargon Defined:

The palp on the maxilla of an Ephemerella nymph (detached and photographed under a microscope) is highlighted in red here.

Palp: A long, thin, often segmented appendage which can protrude from certain insect mouth parts such as the maxillae. Also known as the < />palpus.

A few (not all) of the abdominal tubercles on this Ephemerella needhami nymph are circled. They are especially large in this species.

Tubercles: Various peculiar little bumps or projections on an insect. Their character is important for the identification of many kinds of insects, such as the nymphs of Ephemerellidae mayflies.

Ventral: Toward or on the bottom.

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