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

Taxonomic Navigation -?-
» Family Ephemerellidae (Hendricksons, Sulphurs, PMDs, BWOs)
Genus in EphemerellidaeNumber of SpecimensNumber of Pictures
Attenella528
Caudatella47
Dannella00
DrunellaBlue-Winged Olives28124
EphemerellaHendricksons, Sulphurs, PMDs128571
EurylophellaChocolate Duns22108
Matriella00
Penelomax325
Serratella11
Teloganopsis16
Timpanoga12

3 genera aren't included.
Common Name
MatchCommon Name
****Hendricksons, Sulphurs, PMDs, BWOs
Pictures Below ↓

This is page 4 of specimens of Ephemerellidae. Visit the main Ephemerellidae page for:

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

Pictures of 206 Mayfly Specimens in the Family Ephemerellidae:

Specimen Page:1...345...22
Female Drunella tuberculata Mayfly DunFemale Drunella tuberculata Mayfly Dun View 14 PicturesI don't know for sure that this is Drunella tuberculata, but that's my best guess for now.

It certainly has a different look and much more robust body shape from Drunella lata duns I photographed a couple weeks earlier, so I doubt it's that species. Using distribution records to eliminate other choices narrows this down to Drunella tuberculata or Drunella walkeri.

Markings described for the abdominal sternites (
One sternite of this Isonychia bicolor mayfly spinner is highlighted in red.
One sternite of this Isonychia bicolor mayfly spinner is highlighted in red.
Sternite: The bottom (ventral) part of a single segment on an insect's abdomen.) of the male spinner of Drunella tuberculata are suspiciously similar to those on this female dun. Also, this dun is 9.5mm long (my ruler pic isn't very good, but I'm basing this on measuring the real thing). The size range given in the old Allen & Edmunds keys for walkeri females is 7-8mm, while tuberculata is 9-11mm. For these reasons I'm sticking it in tuberculata for now.

This is the only Drunella mayfly I saw all day. I scooped it off the water as it emerged at around 7pm from a big Catskill tailwater.
Collected June 1, 2007 from the West Branch of the Delaware River in New York
Added to Troutnut.com by Troutnut on June 8, 2007
Drunella doddsii (Western Green Drake) Mayfly NymphDrunella doddsii (Western Green Drake) Mayfly Nymph View 12 Pictures
Collected July 17, 2011 from the Gulkana River in Alaska
Added to Troutnut.com by Troutnut on July 20, 2011
Male Drunella doddsii (Western Green Drake) Mayfly DunMale Drunella doddsii (Western Green Drake) Mayfly Dun View 13 Pictures
Collected July 17, 2011 from the Gulkana River in Alaska
Added to Troutnut.com by Troutnut on July 20, 2011
Male Ephemerella invaria (Sulphur Dun) Mayfly DunMale Ephemerella invaria (Sulphur Dun) Mayfly Dun View 7 Pictures
Collected May 26, 2007 from Penn's Creek in Pennsylvania
Added to Troutnut.com by Troutnut on June 4, 2007
Ephemerella subvaria (Hendrickson) Mayfly NymphEphemerella subvaria (Hendrickson) Mayfly Nymph View 3 PicturesThis is one of the nymphs I collected doing something very, very strange on March 17th 2004. In the middle of the day, around 2 pm, in the water right around my feet I watched lots of Ephemerella nymphs clumsily swimming up all the way to the surface and then just kind of drifting and wiggling around in the water column. None hatched. They seemed to do it more intensely when the sun was out. It wasn't the time of day for the normal invertebrate drift phenomenon, and as far as I know invertebrate drift doesn't involve this kind of clear effort to swim all the way to the surface. I didn't need a net to catch them, I just reached down into the water and grabbed them with my fingers just below the surface.

The prominent abdominal tubercles (
A few (not all) of the abdominal tubercles on this Ephemerella needhami nymph are circled. They are especially large in this species.
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.) aren't quite black, though, and the general color is a dark brown, though I saw nymphs with all Hendrickson color stages behaving strangely.
Collected March 17, 2004 from the Namekagon River in Wisconsin
Added to Troutnut.com by Troutnut on January 25, 2006
Female Drunella cornuta (Large Blue-Winged Olive) Mayfly SpinnerFemale Drunella cornuta (Large Blue-Winged Olive) Mayfly Spinner View 6 Pictures
Collected May 27, 2007 from Brodhead Creek in Pennsylvania
Added to Troutnut.com by Troutnut on June 4, 2007
Penelomax septentrionalis Mayfly NymphPenelomax septentrionalis Mayfly Nymph View 3 Pictures
Collected May 13, 2007 from the Delaware River in New York
Added to Troutnut.com by Troutnut on May 18, 2007
Male Drunella cornuta (Large Blue-Winged Olive) Mayfly DunMale Drunella cornuta (Large Blue-Winged Olive) Mayfly Dun View 12 Pictures
Collected May 29, 2007 from Brodhead Creek in Pennsylvania
Added to Troutnut.com by Troutnut on June 4, 2007
Male Ephemerella aurivillii Mayfly DunMale Ephemerella aurivillii Mayfly Dun View 9 PicturesThis dun hatched in my aquarium on July 16th from an easily identified nymph collected on July 10th, and it molted into a spinner after I photographed it. The beautiful spinner form is listed as separate specimen. I forgot to photograph the dun with the ruler, but naturally his size is pretty similar to what it was as a spinner.
Collected July 10, 2011 from Nome Creek in Alaska
Added to Troutnut.com by Troutnut on July 16, 2011
Ephemerella aurivillii Mayfly NymphEphemerella aurivillii Mayfly Nymph View 5 PicturesClose examination under a microscope showed definite small tubercles (
A few (not all) of the abdominal tubercles on this Ephemerella needhami nymph are circled. They are especially large in this species.
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.) on the back of this nymph.
Collected February 5, 2004 from unknown in Wisconsin
Added to Troutnut.com by Troutnut on January 25, 2006
Specimen Page:1...345...22
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