Hi AllanOK,
I caught some trout from the ones they put in our local lake last year on midge flies. The midges I saw that were of any size at all were mayflies, but there were much smaller midges present also.
I tied up some midges with the hackle trimmed on the bottom like thorax flies, and caught a few fish on them, but I tied them like a Wulff, not like true thorax fly, again just trimmed the hackle flat on the bottom. I usually didn't see the fish rising until just 30 minutes before dark. The flies I tied were number 18s, and I think also number 20s, if I remember correctly. I will say, however, that part of the time my #18s looked like B-52s out there compared to the live mayflies.
I tied them in olive with grizzly hackle, in cream with cream hackle, and in black with dark hackle. I also tied some soft hackle versions of the same flies, and dressed them with floatant so that the flies would float in the film. It was cold...I wore warm stuff.
I would then watch to see where fish were rising, and try to get close enough to fish that spot.
Regards,
Gandolf