Sunday, October 26, 2014

Giants and Goerids -- back to Sugar Hollow

It was a beautiful day to go into the mountains -- so back to Sugar Hollow even though I didn't expect to see very much.  And I didn't: I saw a lot of Giant stoneflies, various sizes, and some Goerids (weighted-case makers), and that's about it.  It's still early for much activity in these small mountain streams.

I wasn't going to file an entry today.  Still, when I downloaded my photos, two things commanded attention.  The first -- I got some very nice photos of two Giant stones, one little one large (though it won't mature until spring).

These are Pteronarcys proteus which, to date, is the only species I've found in this stream.   Note that the lateral abdominal hooks are "appressed" (i.e., they don't stick out to the sides as they do on P. biloba).  But while they are easy to see on abdominal segments 1-6, they are "not conspicuous on abdominal segments 7-8" (Beaty, "The Plecoptera of North Carolina," p. 28).


The second thing that I noted had to do with one of the Goerids I kept for my photos.

If you look closely at the 1st abdominal segment, you'll see that the dorsal hump is very prominent -- the lateral humps are there, but they do not stick out from the sides as we'd expect on this type of larva.

This is interesting because in an article written a long time ago -- 1921 -- John Thomas Lloyd noted this feature as characteristic of Goera calcarata.  "On the first segment the dorsal hump is well developed; the lateral humps are present, but flattened."  ("The Biology of the North American Caddis Fly Larvae," Bulletin of the Lloyd Library of Botany, Pharmacy and Materia Medica: Entomological Series, No. 1, p. 81.)  And it was indeed G. calcarata -- 3 pairs of metanotal sclerites and no sternal plates (see Beaty, "The Trichoptera of North Carolina," p.87).   Pretty neat.

Other pix from this morning.

Nice supply of colorful gravel and pebbles in this particular stream.

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