Thursday, April 17, 2014

But the most common Green Stonefly we see is Sweltsa sp., and they're getting mature

Back to Sugar Hollow today, to one of my favorite streams.  And I saw a lot of these nymphs: the Green Stonefly (Chloroperlid), genus Sweltsa.  Note how these nymphs differ from the Haploperla Chloroperlid we found yesterday.


Color, -- greenish brown: tails -- medium length, slanting away from the body; size when mature --- ~7 mm; wing pads -- inner margins close to parallel to the line of the body.


Color -- golden brown; tails -- short, point straight back from body; size when mature -- 7-8.5 mm; wing pads -- inner margins diverge from the main line of the body.

Just in case you need to identify Greens to the level of genus.

"Mature" was the name of the game at this small stream today.  Beautiful insects with black wing pads that by now could be flying around.

1. Pronggilled mayfly, Paraleptophlebia sp. (mollis?)

2. Flatheaded mayfly, Epeorus pleuralis

3. And the flatheaded mayfly, Maccaffertium merririvulanum.  Not quite mature, but the wing pads are long and dark brown: size, close to 16 mm.

And the defining feature -- the pale "V's" on terga 5, 7, and 8.

Only found in pristine, headwater streams.  Like the one we went to today.


Of course not everything was mature.  Even here the spiny crawlers (E. dorothea) are taking over the stream by the hundreds, but they're still pretty small.  And I did find one real small Perlodid.

It has a long way to go before it matures into this --

one of our unknown Isoperlas.

One of my favorite sights in the spring in Virginia -- redbud trees.  Our flowering trees are in bloom wherever you look.

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