What are the dark, approximately small-mosquito-sized flies that fly and bounce at the surface of creeks, ponds, and tailwaters around north Texas, even in late-winter? Some kind of ovipositing midge? The hatch activity I've seen has been most concentrated near sunset.

I've seen rises to these (presumably) and caught juvenile crappie under them. It would be nice to get a handle on what the bugs are in order to learn their lifestages and try some patterns accordingly.

Chironomids? (You're going to need a bigger magnifying glass.)

John Kent�s Top Ten Chironomid Patterns

They're some sort of midge.

i second the midge