Saturday, April 27, 2013

A spring day on two small streams in Sugar Hollow

It's spring, and there are a lot of mayfly and stonefly adults flying around out by the streams.  This female spinner ("imago", a mayfly that's ready to mate and lay eggs) happened to land on my friend's net as I was taking some pictures.  How could I resist?!

The only large mayflies that should be hatching right now in these small mountain streams are Epeorus pleuralis (Quill Gordon), Maccaffertium pudicum (March Brown?), and Maccaffertium merririvulanum.  But this doesn't seem to match any photos we've seen of those insects.  If someone knows what this is, please let us know.  I can imitate adults when I'm fishing; but I can't ID them to the level of species.

Back to the work with which I'm a lot more familiar!  Even these small mountain streams are filled with spiny crawler nymphs at the moment (E. invaria mostly) -- you have to look around to find other things.  But other things there are, so it's well worth making the effort.

1. A beautiful, mature, Clioperla clio Perlodid stonefly.  Absolutely gorgeous!

2. More Perlodids.  The first, an Isoperla holochlora -- small, but note how the wings have already spread -- the second, one of two Isoperlas that we see in these streams: both remain unidentified to the level of species, even by the pros.

3. A fairly mature Ameletid, Ameletus cryptostimulus.  Hmm....could that be our mayfly?  They too will be hatching.

4.  And look at this, there are still lots of Uenoids up here in these high elevation, cold water streams.

1. Neophylax aniqua.  (If you look closely at the first photo, you can see the tubercle on its head.)

2. And Neophylax, species unknown at the moment.  (No tubercle, no clavate gills, head dark brown to black.)

5.  A young, Spike-tailed dragonfly nymph, Cordulegastridae (possibly Cordulegaster erronea).  (Interesting fact -- Cordulegaster is a dragonfly that I've only seen in small, headwater streams.)

6.  A fully mature Epeorus pleuralis.  The bottoms of rocks were covered with them.  (Of course, not all of them were mature -- but many, many were.)

7.  Well, and two spiny crawlers for good measure.  Look to me like E. invaria.


Note:  There is an excellent online key for the identification of Odonata (dragonflies and damselflies) to the level of species.

No comments:

Post a Comment