American Grannom

Overview

The American Grannom, commonly called the Mother's Day Caddis, is a caddisfly (order Trichoptera) known for a dense, well-timed hatch that draws heavy angler attention each spring. Found in cold, fast-moving rivers and streams across North America, it triggers as water temperatures climb into the low 50s to mid-60s Fahrenheit. Adults show a dark brown to olive body with dark, grayish-tinted wings. Hook sizes: 12 to 16.

Nymph

Nymphs run 0.75 to 1 inch, olive to brown with a stout, segmented body and darker thorax. They're bottom-dwellers, clinging to rocks and submerged vegetation in fast water and feeding on detritus and small invertebrates, migrating to shallower water as they near emergence. Hook sizes: 12 to 16. Dead-drifted presentations near rocks and logs are effective.

Dry/Adult

The adult measures 0.5 to 0.75 inches, with a dark brown to olive body and large, translucent, grayish-tinted wings. Hatches run heaviest in late afternoon or evening, occasionally spilling into early morning, with adults fluttering on the surface or perched on streamside vegetation. Trout rise eagerly during the emergence, making it a strong topwater window. Hook sizes: 12 to 16.

Curated by the IdentaFly fly fishing team.