River Test · hatch chart
Brown trout from 3 April to 30 September; grayling over the winter on some beats
By month
JanFebMarAprMayJunJulAugSepOctNovDec
| Month | Insect | Stage | Size | Time | Intensity |
|---|---|---|---|---|---|
| Apr | Grannom caddis (Brachycentrus) | Adult | #14 | 12:00-16:00 | |
| Apr | Large Dark Olive (Baetis rhodani) | Dun | #14 | 13:00-16:00 | |
| May | Mayfly (Ephemera danica) | Dun and spinner | #10-12 | 11:00-16:00 | |
| Jun | Blue-Winged Olive (Serratella ignita) | Dun at dusk | #16-18 | 19:00-22:00 | |
| Jul | Pale Watery (Procloeon pennulatum) | Dun | #18 | 19:00-21:30 | |
| Aug | Sedge caddis (various) | Adult, evening | #14-18 | 20:00-22:30 | |
| Sep | Blue-Winged Olive (Serratella) | Spinner fall | #18 | 14:00-17:00 |
Flow and visibility
Chalk streams rise from the ground, not from the sky, so the Test's flow responds to rainfall over a period of weeks rather than days. A wet winter gives strong, cool summer flows; a dry one leaves the river low, warm and weedy by August, and the beats may close early on welfare grounds. Check the Environment Agency gauge at Chilbolton if you want to know what you are walking into.
The insect plate
