Caddis · Aquatic insect
Evening Sedge
Hydropsyche

Size
8–13mm
Hook size
#14–12
Hatch window
Season May–SeptemberPeak time 18:00–22:00
Water temperature
15° peak
11°22°
Hatches from 11°C, peaking at 15°C, tailing off by 22°C.How fish feed on it
Adult insects on the water are inefficient — a caddis skittering to lay eggs, a stonefly blundering about after crawling out, neither built for elegance. Trout treat it as an easy meal and a bit of theatre at once, chasing a moving fly with more enthusiasm than they'd ever give a still one. Movement is the tell; a static adult imitation often just sits there unloved.
Flies that imitate this
Ecology
Where you'll find this
- British IslesPresent
- IberiaPresent
- The AlpsPresent
- ScandinaviaPresent
- Continental EuropePresent
- Atlantic fringePresent
Present throughout
About the genus Hydropsyche
Hydropsyche is a genus of net-spinning caddisflies. The larvae build fixed retreats with silk capture nets in flowing water, and the adults are among the commonest sedges of summer evenings.



