Stoneflies are among the earliest aquatic insects to become active each year and are an important food source for trout on fast-flowing rivers. Although they rarely receive the same attention as Large Dark Olives or the famous Mayfly hatch, stoneflies are found on many clean, well-oxygenated rivers throughout the UK and can provide excellent early-season fishing. The family includes several species, from the small dark stoneflies of early spring through to Yellow Sally stoneflies that appear during the summer months.
Unlike upwing flies and sedges, stoneflies do not emerge through the surface film. Instead, the mature nymphs crawl from the river onto exposed stones, bankside vegetation, bridge supports or tree roots before shedding their skins and emerging as winged adults. Because of this, trout rarely feed on emerging stoneflies in the surface film. They are far more likely to intercept drifting nymphs before they leave the water or take adult insects that accidentally fall or are blown back onto the surface.
Stonefly nymphs are flattened, powerful insects perfectly adapted to life in fast currents. They live beneath stones and amongst gravel where they cling tightly to the riverbed. During periods of increased flow, or as they become ready to hatch, some nymphs become dislodged and drift naturally downstream, making them an important food source for trout.
Adult stoneflies are generally poor fliers and tend to remain close to the river after emerging. They are often found resting on bankside vegetation before returning to the water to lay eggs. Wind or overhanging vegetation frequently causes adults to fall onto the river, providing trout with another easy meal.
Different species emerge at different times throughout the year. Smaller dark stoneflies are common during late winter and early spring, while Yellow Sally stoneflies are more typical of early summer. Collectively, they provide trout with a reliable source of food over several months, particularly on upland freestone rivers.
At Peaks Fly Fishing, we always carry a few stonefly patterns when fishing fast rivers during the early part of the season. While they may not produce spectacular blanket hatches, they regularly account for trout feeding close to the riverbed and can also be surprisingly effective as larger searching patterns when little other insect activity is taking place.
## Recommended Fly Patterns
### Nymphs
* Snipe & Purple Spider
* Black Creeper
### Adults
* Stonefly
## Peaks Fly Fishing Tips
* Concentrate on fast, well-oxygenated rivers with clean gravel and stony riverbeds.
* Fish stonefly nymphs close to the bottom where the naturals live.
* Rising water levels often dislodge nymphs and can produce excellent fishing.
* Adult stoneflies are most often found close to the banks rather than in midstream.
* Don't overlook stoneflies simply because the hatch isn't obvious - they provide trout with an important food source throughout much of the early season and are a valuable addition to any river fly box.
