Grannom (Brachycentrus subnubilis) are a member of the Caddis family (Trichoptera order) and are among the first of the UK’s major hatches in Spring. Hatches can be huge, and I mean massive, to the point where every Grannom seemingly tries to crawl up your waders, under your glasses, down your neck, or smack into you as they are blown up or downstream by the usually unstable Spring weather.
Trout can go crazy during these hatches; however, it never appears to be the adult Grannom they are interested in. Instead, trout will usually gravitate to the emerging Grannom (and even their empty shucks), of which (should you be lucky enough to experience these hatches on your rivers) will be drifting downstream in their millions.(more…)