Mayfly · Aquatic insect
Large Spurwing
Procloeon pennulatum
Size
7–9mm
Hook size
#16–14
Outside the hatch
Nymphs are in the water all year, long before and after the hatch window — the season and temperature figures on this card describe when the adults emerge, not when this stage is available. It very nearly always is.
How fish feed on it
This is the nymph worth fishing. Agile darters swim freely and enter the drift readily, so trout see them all day, every day — no hatch required, no rise to watch for. A fish holds its lie and tilts a few inches either way to take them, with an economy of movement that looks almost bored. Most of the year's calories arrive exactly like this.
Flies that imitate this
Pheasant Tail Nymph
Ecology
Where you'll find this
- British IslesPresent
- IberiaPresent
- The AlpsPresent
- ScandinaviaPresent
- Continental EuropePresent
- Atlantic fringePresent
Present throughout
Identification
Procloeon pennulatum is a species of small minnow mayfly in the family Baetidae. It is found in North America.