Saturday, February 12, 2011

Stream Report: Lickinghole Creek near Crozet


(Well, I've been ignoring these in my reports -- which is hardly fair -- but after all, they are pretty ugly!
Crane fly larva (family Tipulidae; genus Tipula).   We always find them in leaf packs during the fall and winter.  This larva was about 3/4" long -- short and pudgy -- when I picked him up and put him into my plastic collecting bowl.  But note how long they are when they stretch out.   They move by contracting and expanding like an inch worm.)

I went to Lickinghole Creek today in search of small minnow mayflies (family: Baetidae).  My notes from 2009 say that I found "lots" of them here on 1/22, and that they were already big.  They should be.  This is the nymph that provides the exciting "Blue-winged Olive" hatch for fly fishermen as early as March (see the entry above for 1/2/11).  I found none.  In fact, I've found hardly any in any of the streams I've been to so far this winter.  The Doyles River is a good small minnow stream, as is Ballinger Creek in Fluvanna -- so, I'll be off to those streams next week.

I'm concerned that, to date, I've seen very few mayfly nymphs of any kind, and I worry that the drought conditions we had last summer and early fall may have harmed the mayflies when they were in the fragile state of eggs or nymphs in early instars.  I guess time will tell.  The only mayflies I saw today were two flatheaded mayflies (a photo below), and two, small, brushlegged mayflies.   I saw no spiny crawlers -- and by now, we ought to be seeing that family as well.

What did I see?  1) large winter stoneflies -- Strophopteryx (lots of them) and Taeniopteryx (only a few);
2) two small winter stoneflies; 3) Common netspinning caddisflies (lots of them); 4) Uenoid case-maker caddisflies (a fair number); 5) black flies (a fair number, but certainly no "colonies"; 6) crane fly larvae (a couple); 7) fingernet caddisflies (two); 8) a few midges (but they were big); 9) one saddle case-maker caddis; and 10) several large "Common" stoneflies (family: Perlidae; genus: Acroneuria).

I got some good photos, so let me sign off with them.

1) three nice shots of a fingernet caddis:








2) a flatheaded mayfly (genus Stenonema)


3) and one of the common stoneflies:


Note the "hairy armpits," especially on the left side.  Also note the "silky fringe" of hairs on the inside of the cerci (tails) near the base.  This is one of the defining characteristics of the genus Acroneuria.

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