A "Cheat Sheet" for spiny crawler (Ephemerellidae) genera

Ah yes, the mayflies we love to hate.   Come May, there's simply no way to avoid them.  They're all over the place: they're in the leaf packs, in root balls, on the bottoms of rocks and on the tops of rocks, especially if the rocks are covered with moss.   Most of the spinys we see in our samples in May are genus Ephemerella, specifically E. dorothea: for fly fisherman, PED's (Pale Evening Duns).  There are two other genera that I see in the summer -- Serratella and Teloganopis -- but they are not around in large numbers.  It is not hard to sort out the genus IDs for spiny crawlers, though for some features you might need a loupe.

     A "Cheat Sheet" for spiny crawler (Ephemerellidae) genera

I. gills on abdominal segment 4 LARGE, covering those on segments 5-7: Eurylophella

II. gills on segments 3-7 all the same size

1. intersegmental setae dense on cerci (tails) -- tails look "bushy"; all femora the same size: Ephemerella

2. intersegmental setae dense on cerci (tails) – tails look "bushy"; fore (front) femora very broad with "tubercles" (spiny bumps) on the front edge: Drunella

3. cerci "short and spiky" and lack intersegmental setae; "tubercles" present on rear edge of abdominal terga: Serratella

4. cerci "short and spiky" and lack intersegmental setae; no "tubercles" on rear edge of abdominal terga: Teloganopis

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I. gills on abdominal segment 4 LARGE, covering those on segments 5-7: Eurylophella

I've not seen a lot of these nymphs.  I've found a couple in Buck Mt. Creek and some in the small streams in Sugar Hollow.  A spring taxon.

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II. gills on segments 3-7 all the same size

1. intersegmental setae dense on cerci (tails) -- tails look "bushy"; all femora the same size: Ephemerella

(Also the nymph at the top of the page.)

As you can see, they come in a wide range of colors.  Don't go by the color, always use the morphological features.   This is the spiny genus we most commonly see.  I know we'd all like to see less of them!

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2. intersegmental setae dense on cerci (tails) – tails look "bushy"; fore (front) femora very broad with "tubercles" (spiny bumps) on the front edge: Drunella

Not terribly common.  I've found three different species.  Two of them we find in the spring, the other -- the one in the photo directly above -- is around in June and July.

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3. cerci "short and spiky" and lack intersegmental setae; "tubercles" present on rear edge of abdominal terga: Serratella

A "summer spiny."  They're small: dark brown or black.  Tolerant of warm water conditions.

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4. cerci "short and spiky" and lack intersegmental setae; no "tubercles" on rear edge of abdominal terga: Teloganopis

I've only seen this one at the Rapdian River, so I don't think it's common.  Like Serratella it's around in the summer and it has those short, spiky tails.  You'll need a loupe to check the abdominal segments

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There are four genera in the Southeast that I haven't seen: Attenella, Dannella, Penelomax, and Tsalia.  Attenella and Penelomax are uncommon and Tsalia is rare.   Not sure we're going to find them.   We could run into Dannella -- "primarily lotic, typically in areas of slower flow and silt, often collected from woody debris" -- though I'm not sure I normally look in those locations.  (See Beaty, "The Ephemeroptera of North Carolina, pp. 45-65.)

Afraid this is a key that you can't really use until next spring and summer, though "tiny spinys" show up in the winter.