» Order Ephemeroptera (Mayflies)
8 families aren't included.
This is page 2 of specimens of Ephemeroptera. Visit the main Ephemeroptera page for:
- The behavior and habitat of Ephemeroptera.
- 67 underwater pictures of Ephemeroptera.
- 2 streamside pictures of Ephemeroptera.
Pictures of 716 Mayfly Specimens:
Male Ephemerella aurivillii Mayfly Dun
View 14 PicturesThis is the most widespread species of Ephemerella, and also the most abundant in some places, but nobody I've talked to seemed to know what its duns looked like, and there were no pictures of its duns online or in any angling books. That mystery is solved with this male dun, which hatched from a definitively identified nymph. Female 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 (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.