Nordic Springfly

This is the one that opens the season, not the one that follows it — published life-cycle studies on this species describe nymphal growth resuming in spring before the ice has even finished melting, among the most cold-hardy timing documented for any stonefly. Norwegian anglers describe the whole stonefly season as starting 'fra isen går' — from ice-out — and on the rivers this species dominates, that's this fly, not a generic early-season placeholder. Overwhelmingly a Fennoscandian insect: Norway, Sweden and Finland between them account for essentially every record of it that exists. Fish it as you would any early stonefly — Pheasant Tail Nymph or Coch-y-bonddu for the searching work, Snipe and Purple when egg-laying females are back on the water — and don't wait for warmer weather to start; by the time the water feels fishable to you, this one's already been active for weeks.

• ScandinaviaPresent