Sulphur
Sulphurs—primarily Ephemerella invaria and Ephemerella dorothea—produce some of the most dependable late‑spring and early‑summer hatches in trout country. These mayflies typically run from size 14–18, with creamy‑yellow bodies, pale wings, and emergence windows that often overlap with evening spinner falls. Trout feed aggressively during the hatch but can become selective when the water is clear or the emergence is prolonged.