If you skim the list there are several Odonates listed (including damsel nymphs). However, if you add them up they are still a tiny fraction of the Diptera (chironomid) numbers. I think Irafly made the observation last spring that trout are either "looking for skittles or hoagies" referring to chironomids and leeches/dragon nymphs, respectively. And where are leeches on that list? They are invertebrates, no?
In the case of Grimes Lake, all sampling took place on 08/16/2007. For other lakes, sampling also took place during the summer (July, August, or September) of 2007. However, had the sampling taken place during different seasons (spring, summer, fall, winter), I would expect the results to differ based on the sampling date.