The Trico Seasons

Charles Meck offers an excellent rundown of trico (Tricorythodes) hatches in the U.S., including listing the biggest seasonal activity and the best places to find and fish tricos on both sides of the country. Here’s an interesting tidbit on why you’ll spend most of your time matching the olive-bodied female dun rather than the males: “Have you ever seen a male Trico dun? If you have you probably haven’t seen many. Why? A few decades ago Robert Hall conducted a study of the Trico for his doctoral requirements. In that study he found that male duns often emerge from 10 P.M. until 2 A.M. So, don’t worry about matching the male dun. The olive-bodied female dun emerges from 5 A.M. to 11 A.M. depending on the weather conditions and the time of year.”
Tricos begin coming off earlier in the U.S. east than they do out west, and the challenge often becomes finding cool-enough air temperatures, as Bill Ferris points out on Cumberlink.com. “Unlike many other mayfly hatches the trico hatch begins along about July 5th and on any given morning until the first hard frost the little mayflies flutter over the riffles on many of our trout streams and trout rise to eat them. I’m told that the first hatching insects are about a size 20 and as the season warms through summer the size diminishes to about a 24 or 26. I can’t see to tie a size 26 fly on my tippet so the smallest I tie is a size 24 but mostly I compromise and simply tie 22’s.”