The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.
This one was surprisingly straightforward to identify. The lack of a sclerite at the base of the lateral hump narrows the field quite a bit, and the other options followed fairly obvious characteristics to Clostoeca, which only has one species, Clostoeca disjuncta.
My friend Willy captured this early instar damselfly nymph and brought it to me for identification. It is more robust and stocky at this early stage than the spindly appearance of the later instars, and its appearance is less familiar.
DMM on Nov 26, 2006November 26th, 2006, 5:05 pm EST
One reason I think it's Argia, is that this genus is characteristically "stubby" and "robust" through the last instar. Without verification, I think it is the stubbiest of the Zygoptera.