Large Stonefly

 Large Stonefly

The Stonefly is a member of the Plecoptera family - consisting of many distinct species, however, the difference between species is minimal and as far as the fly angler is concerned they can all be grouped together as one. These flies are easily identified at this time of year as they will be the only fly on the water which has two separate pairs of wings.


Where To Find Them

Similar to March Browns, the Large Stonefly are more commonly found on the larger, faster rocky rivers in the north of England, and throughout Scotland, Wales and Ireland.
Large Stoneflies prefer rocky or stony rivers with faster flowing water.

When To Find Them

The Large Stonefly hatch usually starts in the first two weeks of April and usually continues until the end of June.
The majority of stoneflies taken by trout are the adult females, when returning to the water to deposit their eggs. Large Stoneflies are nocturnal, so it is generally best to imitate them either in early morning sessions, or as dusk is drawing in, through to late evening.

What To Look For

Stoneflies are present in most of our rivers between April and July. The nymphs can be easily recognised, as they have 2 tails in a distinctive "V". The adults again are easily recognisable (especially when in the air) as they have 2 sets of wings. 


Stonefly nymphs hatch in the river bed, then make their way to the water's edge and crawl up bankside vegetation and rocks before they hatch into an adult, usually at dusk. For the fly angler, fishing stonefly nymphs is all about "right place, at the right time". Stonefly nymphs generally head for the faster currents and riffles before they hatch, where lots of them get washed off, making easy meals for any waiting fish. So targeting these fast riffles and the heads of pools directly down-stream of them is the way to go (especially in an afternoon).

Female adult stoneflies return to the water to lay their eggs, they generally slap the water with their abdomen to release the eggs; and this is like the dinner bell for the waiting trout! This is when the trout take them as dry flies; rise forms can sometimes be very splashy and sometimes a generic "head and tail", but if you ever see stoneflies in the air, then it's always worth tying on an imitation, especially in early mornings and late evenings.

From a fly fishing perspective the stages which we must try to imitate are:

  • Adult Females
  • Nymphs


The most popular imitations for adult female Stoneflies are either of the dry flies below. Don't worry if you don't have these exact patterns, as anything which has the same general colour, profile and size will do. These flies should be fished as you would any other dry fly, and they should be used as soon as you start to see the females return to the water to lay their eggs; this can be anytime from about 18:00 until after dark.

Adult Females

Parachute Adams


Thorax Adams




If you are fishing during the day, then nymphs are the way to go. Just make sure you are fishing near the bottom, remember: "if you're not getting snagged every now and then you're not fishing deep enough". Take a look at these for some inspiration:


Realistic Stonefly Nymph


Heptagenid Stonefly Nymph

Always keep in mind how deep and how fast the water is when nymphing in the early season, that will tell you how heavy a nymph you need to use. All you need to remember when fishing stonefly nymphs in the early season is that you need to be very near (or on) the bottom, if you're not getting snagged up every so often, you're not fishing deep enough.

Image Sources

Stonefly Lifecycle image: Courtesy of Cabelas (Dave Whitlock - Guide to Aquatic Trout Foods)

Header image: Adobe Stock


This email is brought to you with the sole intent to spread the information around so we can all maybe learn something. If you would like to buy any of the flies contained within this email, we do hope that you will consider us and see what flies we have to offer. If you would like any further details on any of the above flies, they can be found using these links:

Dry Flies:
Parachute Adams
Adams Thorax

Realistic Stonefly Nymph
Heptagenid Stonefly Nymph

The next issue of Hatch Chat will cover the Grannom. Keep your eye's on your inbox in the next few weeks.