Alderfly · Aquatic insect
Alder Fly
Sialis lutaria
Hatch window
Season April–JunePeak time 11:00–17:00
Water temperature
14° peak
10°19°
Hatches from 10°C, peaking at 14°C, tailing off by 19°C.How fish feed on it
The Alder is one of the best-known flies in the book and one of the most over-rated, which is worth saying plainly. The adult is a poor flier that blunders onto the water in May and June, but it is never on it in numbers, and generations of anglers have fished the pattern with more faith than results. Carry it; don't build the day round it.
Flies that imitate this
Alder Fly
Black Sedge
Connemara Black
Bibio
Wet Alder
Ecology
Where you'll find this
- British IslesPresent
- IberiaPresent
- The AlpsPresent
- ScandinaviaPresent
- Continental EuropePresent
- Atlantic fringePresent
Present throughout
Identification
Sialis lutaria is a species of alderfly belonging to the order Megaloptera family Sialidae.