Thursday, May 23, 2013

And another genus of spiny crawler at Buck Mt. Creek: Eurylophella

On my most recent trips to Buck Mt. Creek I've seen a lot of spiny crawlers: two species, Ephemerella dorothea and Drunella tuberculata.  Today I saw one E. dorothea and no Drunellas at all -- but I did see four Eurylophellas.   This is a small nymph: of those I found there this morning, the largest -- the one in the photo at the top of the page -- measured about 7 mm.

It is largely those large gills on segment four of these nymphs that let us ID this particular genus.  Beaty ("The Ephemeroptera of North Carolina," p. 28) describes the genus this way: "gills on segment 4 operculate and largely covering the gills on 5-7; paired tubercles on abdominal segments 1-7; abdominal segment 9 distinctly longer than segment 8."   These are the gills:

And the tubercles on segments 5-7 are pointed out in this photo taken last year.

Last year I concluded that I was finding Eurylophella verisimilis at BMC because of those dark gills on 5-7.  I'm no longer sure of that species ID, so let's just leave this at the level of genus.

Here's another look at our nymph...

And here's a shot of one of the small nymphs that I found.


While I was pleased to see Eurylophellas, I was surprised to see this one: a "water scavenger beetle," Hydrophilidae.

The wierd thing is that as I was getting out of my car at the stream, I was thinking about the various beetles I've found at this stream.  I've seen Dryopids, riffle beetles, and whirligig beetles -- but, I said to myself, I've never seen a water scavenger beetle at Buck Mt. Creek.  And of course I found three of them in the first clump of grasses and roots in which I looked!

Water scavenger beetles come in two different shapes.  The other one looks like this:

This larva was found in the Moormans river on 9/29/11.  Actually, it's the bodies that differ -- the heads look the same.

Other photos:

1. Something I was not expecting to see, a green stonefly, genus Alloperla.

Here's a photo of one I found at the Doyles River on May 23rd (!) of last year.

2. Another "long-horned case-maker," presumably the same species I found here before, Ceraclea maculata.  I didn't keep it -- but the head and the case look exactly the same.

3. Our first Perlesta common stonefly of the season.  This is the one that we will be seeing a lot of in June and July.

4. And, "signs of summer," a narrow-winged damselfly nymph (Coenagrionidae), and that odd-looking club-tailed dragonfly, Hagenius brevistylus.

Can you spot the 4th segment on the antenna?  Just barely visible.

I also saw quite a few Darner dragonflies.  We move into summer.

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