Mayfly · Aquatic insect
Eastern Summer BWO (Drunella)
Drunella cornuta
Size
9–12mm
Hook size
#14–12
Hatch window
Season May–AugustPeak time Late morning–afternoon (overcast best)
Water temperature
17° peak
13°23°
Hatches from 13°C, peaking at 17°C, tailing off by 23°C.How fish feed on it
By the time the spinners are down the fly has finished its job and is simply lying there, spent, wings flat in the film, going nowhere. Trout know the difference between something alive and something that's stopped trying, and they take spinners with a quiet, unbothered sip that's easy to miss if you're still watching for something splashier. Look for them on the glides and in the slack water, wherever the current gathers what's left.
Flies that imitate this
BWO Comparadun
Blue-Winged Olive Parachute
Olive Shuttlecock Emerger
Ecology
Where you'll find this
- North America — EastPresent
Present throughout
Identification
Drunella cornuta is a species of spiny crawler mayfly in the family Ephemerellidae. It is found in North America.