Saturday, March 10, 2012

At the Moment, Not Much Diversity at the Rapidan River

Oh, there were a lot of insects today at the Rapidan River, but there was very little see but Isoperla nr. namatas (Perlodid stoneflies, as in the photo above) and Spiny Crawler mayflies, genus Ephemerella (E. subvaria, E. invaria, and E. dorothea, all three).  If you're getting ready to go out and monitor streams -- the spring sampling season is now underway -- then get ready to have samples that are dominated by these two taxa.

I did find other things.  I saw quite a few pronggilled mayflies, including one that was already mature; a couple of Giant stoneflies (P. biloba); a couple of Common stoneflies (Acroneuria abnormis); and a few Baetis tricaudatus small minnow mayflies.  I also saw Epeorus pleuralis flatheaded mayflies on the bottoms of rocks, common netspinners were under there too.  But the number of I. nr. namatas and the various Spiny Crawlers was simply staggering.  Look for big hatches soon of "Yellow Sallies," "Hendricksons," and "Pale Evening Duns"!

Nothing but photos today.

1. The Isoperla nr. namatas, the most common Perlodid stonefly we find in our streams, are rapidly maturing.  So they are very colorful and richly patterned.

2. A mature pronggilled mayfly (genus Paraleptophlebia) -- with a few gills missing, I'm sorry to say.

3. Baetis tricaudatus, the small minnow mayfly we find in the mountains.

4.  One of two Ephemerella subvarias (Spiny Crawlers) that I located today.  These, too, are rapidly getting mature.

5. Ephemerella invaria.

6. And two more Spiny Crawlers, in a photo that sort of sums up what I saw today in my tray.

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