Sedge pupae are colourful and active.  They should be fished more like a nymph than a dry fly as sedge pupae are strong swimmers.  Trout cannot be too pedestrian when hunting sedge pupae and this works in the fishermen's favour as the fish does not look too carefully at imitations.

 

Hatches tend to start in the late afternoon on warm, still days.  Fishing periods with Sedge Pupa Flies tend to quite short as the trout appear to prefer the adult sedges once they appear on the water at dusk.  However, that window between when the pupae start hatching and dusk can be exciting with trout feeding in an unguarded frenzy!