Early Season (March / April): The main hatches in the early season are the Large Dark Olives, Grannom, Stoneflies, March Browns and the Iron Blue Dun. By far the most important nowadays are the Large Dark Olives, Grannom and Stoneflies. The hatch of March Browns, for which the River Usk was duly famous at one time, is but a shadow of what it once was. Iron Blue Dun hatches are also very sparse and infrequent in recent seasons but, like the March Browns, when they are on the water the trout will feed avidly on them. The Large Dark Olive hatch is usually pretty reliable and some years the Grannom come off the water in clouds and can be found resting on bank-side vegetation and stones in huge numbers. Various Stoneflies appear on all our waters throughout the trout fishing season and includes the Yellow Sally, Needle Fly, Willow Fly and the large Perlid Stoneflies.
May & June: This is a great time to be on the river because there are so many hatches to consider and by now the trout are in fine fettle. Mayflies are found on all of our beats on the main river but their emergence varies greatly from year to year. However, some seasons they have been phenomenal. Most years there are good and reliable hatches of Mayfly on the River Grwynne throughout June. Without exaggerating, these hatches can rival a true chalkstream at times. Other prolific hatches in May / June are the Yellow May Duns, Blue-Winged Olives and Pale Wateries. Medium Olives and Olive Uprights also feature but these are nowhere near as dense as they used to be. Various smaller sedge species start to put in an appearance, as do Hawthorn Flies, Caenis, False March Browns and Brook Duns.
July & August: This is the time of year to usually fish very early or very late in the day. Now the various sedges are about in huge numbers and there are still reliable and dense hatches of the Blue-Winged Olives, Pale Wateries and, in recent, prolonged seasons, Yellow May Duns. Olive Uprights, Small Dark Olives and Autumn Duns are regular hatches at this time of the summer and the trout will often gorge themselves during the day and early evening on Black Gnats, midges and smuts. Terrestrials also feature in the trout’s diet at this time and include items such as ants, Cowdung Flies, Craneflies (Daddy Long-Legs), beetles, moths and caterpillars.
Late Season – September: Various sedges, Blue-Winged Olives and Large Dark Olives hatch in profusion throughout September, and occasionally there are dense hatches of Autumn Duns as well. Sparser hatches of Medium Olives and Pale Wateries also occur. From late July through until the end of the trout fishing season on the River Usk on 30th September, the trout will also feed heavily in the margins on fish fry, especially in low-light conditions at dawn and dusk. Fishing suitable fry imitations at these times can produce excellent sport and some bigger than average specimens.
Trout will feed on freshwater shrimps and various chironomids (midges) throughout the year.
Imitations: Suitable fly patterns to imitate all the flies listed above can be found in most game angling catalogues or in fly tying books. However, most anglers fish with flies that are far too big. Sedges can be tied on hooks up to about size 12 but artificial flies to imitate the various up-winged species, generally, need to be much smaller with sizes 16 – 22 being the norm. You will also need patterns in dry, wet, nymph, emerger and spinner form because the trout can be highly selective, and extremely frustrating, in their feeding habits at times!! Patterns that you would not want to be without during the season are as follows : Greenwell’s Glory, Kite’s Imperial, Olive CDC (various shades of olive), Waterhen Bloa, Hare’s Lug and Plover, Snipe and Purple, Usk Nailer, Partridge and Orange, Czech nymphs (various), Pheasant Tail Nymph, Sedge Pupa (orange, olive and dark green bodies), Rhyac Pupa, Cased Caddis, Elk Hair Caddis and Roman Moser’s Balloon Caddis (tied in a variety of body, hackle and wing tones from black through dark browns to a pale tan colouration), light and dark Bustard-style flies, Klinkhammers (various colours), various gold-head (and tungsten-head) nymphs, GRHE nymph, Mayfly patterns, Yellow May Comparadun, various Sparkle Duns, March Brown, B-W O (especially comparadun-style), Pale Watery (especially comparadun-style), Hawthorn Fly, Black Gnat, Midge patterns (especially black, red and olive), beetle patterns (especially ethafoam or deer hair varities), shrimp patterns (olive and orange), Pheasant Tail, Adams, Grey Duster, Red Spinner, Orange Spinner and a few fry imitations or streamer-type flies.
If you cannot source any of these fly patterns, or in the sizes that you require, then contact one of the local fly tying experts and ask them to tie some up for you, but expect to pay realistic prices. They only use quality hooks and materials and do not charge sweat-shop prices!! As with all things in life – you get what you pay for!!
If you would like perfectly tied flies, they don’t come much better than Gareth Lewis.
He is an expert on “Micro flies” tied down to a size 30 hook!
Gareth demonstrating at the BFFI.
If you would like some good “Salmon & Sea Trout” flies then Alun Rees “The Enigmatic Angler” is a good choice.
Below is his “Secret Weapon Mount” Sea Trout Pattern.
Alun with a fine Sewin.