Baëtis fuscatus - Pale Watery

The medium olive is an important summer fly on chalk streams and on many spate rivers too. Peak hatches occur in May and June, but these flies are to be found on Welsh rivers through until at least August. The nymphs are agile darters.

Dun

Dun - female

The dun (a female is pictured above) hatches from mid morning until late afternoon or early evening and tends to come off the water in a trickle hatch (unlike, for example, March Browns, which usually come off in flushes).

Dun - male

The male dun (above) is distinguished by its large orange eyes - not that trout show any tendency towards gender prejudice!

Spinner

Spinner - female

On warm evenings from sunset until dusk the female spinners return to the water to lay their eggs. To lay her eggs, the pale watery spinner crawls down emergent vegetation to deposit them below the surface.

Males get blown onto the water on breezy evenings, and occasionally the result is a selective evening rise. The male spinners are distinguished by their very pale bodies and large yellow eyes.

Spinner - male