I agree that chironomids would be in order. The first week of May you might run into a hatch of a quite large, pale pinkish-orange chironomid endemic to the area known as the pink lady. the pupa is about a #10-#8, and the trout like em real good. But bring all sorts of chironomid pupae, some olive pheasant tails in #14-#18 for callibaetis nymphs, some damsel nymphs, and some wooly buggers and/or leech patterns. Aren't there "goldfish" in Concunally? Maybe some zonkers. I've never fished Concunally, but the lakes in that neck of the woods do seem to have caddis, although you will likely be there a little early for that. You'll likewise be a little early for the callibaetis hatch, but I'd bring some dry flies (callibaetis parachutes, comparaduns, or Adams parachutes)and emergers just in case. Other lakes in the area worth trying are Aeneus, Ell, Blue, and of course Chopaka.