When these are blooming, you know Sulphur nymphs are ready to hatch!
Water temperatures will be in the 60’s. The Sulphurs will kick into high gear around June 9th.
Sulphurs duns will appear about 8 pm. Around 8:30 pm, look for ephemerrella rotunda spinners over the riffles, there can be millions! Wait for the fish to start feeding on the spinners then fish the feeding lanes below the riffles. Have Pale Evening patterns in #16. In the morning many anglers observe paraleptophlebia mollis and mistake them for tricos.
Our experience indicates p. mollis are unimportant to the angler.
In the daytime successful flies will be, Sulphur Nymphs, Ants, Craneflies, Hares Ears, Elk Hair Caddis, Pheasant Tails and .Midge patterns like Al's Rats and Griffith Gnats.
In the evening , Pale Evening Dun, Sulphur patterns and Light Cahills. Late June can bring the first tricos..
When these are blooming, you know Sulphurs are over.