Caddis are the most abundant insect on the Current followed by Blue Winged Olives, Trico's, Hex, and March Browns.
Caddis usually run in the size 14-18 range, brown with brown, gray, yellow or olive bodies. They look like little moths fluttering around, but theres a big October Caddis which usually runs about a size 6-8. Trico's and BWO are tiny usually size 18-24 and look like little gray wispys with big wings. Hex and March Browns are big mayflies, but they usually emerge and fall around dusk.
FWIW, Imitating insects works best on the little fish, bigger ones tend to prefer shiner minnows and sculpins. Cheers.