Here is some information I found on the Trico hatch. This is just a little entomology for the day...
Identification
There are three main species that are important to North American anglers: T. minutus, which hatches across the country, and T. stygiatus and T. allectus, which are most prevalent both in the East and Midwest. T. minutus is slightly larger than the other two species but because of their similar appearance and life cycles, there is little need to distinguish one from another.
Trico duns and spinners range in size from 3.5 to 6.5 mm and can be imitated with size 18 to 26 hooks. They are the only small mayfly you are likely to encounter during the morning hours of the summer and are easily identified by the lack of a hind wing. Tricos are sometimes confused with White-winged Sulphurs from the Caenidae family, which also have no hind wing, but these insects usually inhabit warmer, slower waters and most often hatch in the late afternoon and evening.
Anyone here use patterns imitating them right now?