When does the Late March Brown hatch?

May–July, typically 12:00–15:00. It starts from about 9°C, peaks around 13°C and tails off by 18°C.

What flies imitate the Late March Brown?

March Brown, March Brown Spider, typically on a #12–10 hook.

Spinner stage: 10–14mm. That matches a #12–10 hook.

Mayfly · Aquatic insect

Ecdyonurus venosus

Size

10–14mm

Hook size

#12–10

Hatch window

Season May–JulyPeak time 12:00–15:00

Water temperature

13° peak

9°18°

How fish feed on it

An evening return over the rough water. Thin, and rarely the making of a day.

Flies that imitate this

March Brown

March Brown Spider

Ecology

Rivers & stillwaterAlpine riversSpate rivers

Where you'll find this

Present throughout