Natural flies of the River Don

Natural Flies Of The River Don


The Upwings can be loosely categorised into those with a large hindwing and those with small hindwing. Most of the large hindwing flies are the Stoneclinger nymphs and the small hindwing are the Agile Darter style nymphs. The only exception is the proper Mayfly, which is localised on the Don, has a large hindwing and the nymph is a Silt Burrower.


Nymphs of the River Don

The nymphs come in several types, Stoneclingers, Agile Darters, Crawlers and Burrowers. On the whole, these are dark in colour, with paler undersides to blend in with the river bed.

You will find the Stoneclingers in rocky, streamy water, where they attach themselves to the stones.

The Agile Darters and Moss Crawlers can also be found attached to stones in the rocky sections of the river, but you'll find them around weeds and structures on the river bed as well. This can often be species dependent and will affect which insects you might find in certain areas.

The same can be said for the silt crawler and burrowing nymphs, which require a softer section of the river bed to make their habitat.

Nymphs of the River Don

In recent decades, storms have altered the river bed in large floods and extreme conditions, this has dispersed a lot of the silt and weed beds to different parts of the river, often taking the insects with it.

So what used to be very localised hatches in the river catchment, can now be found more spread out, and you may be surprised by some of the hatches that occur that appear to be ignored by the trout, as they are not used to seeing those insects in their stretch of the river.

Essentially, the flies to imitate them are the same, just vary the size. Most of the nymphs when they start to emerge will have very dark wing cases and their bodies will absorb some air to help them float to the surface, so a shiny rib and dark thorax cover is usually a good addition to any artificial fly.

Nymphs of the River Don


Stoneclingers: Bead headed Pheasant Tail or bead headed Hares Ear nymphs.

Agile Darters: Bead headed and non bead headed Pheasant Tail.

Silt Crawlers: A large bead headed Pheasant Tail or specific Mayfly nymph pattern.

In rough order as you will find the flies hatching during the season.

First up: The Large Dark Olive

River Don - Large Dark Olive

The Large Dark Olive is an Agile Darter nymph and it can be found almost everywhere on the river when it is hatching.

When emerging it takes a few moments in the surface to shed its shuck and that is where the trout will really target it.

It can hatch in large flurries early in the season and often appears in its largest numbers when the weather is at its worst.

It is a particular favourite of the trout to rise to and is the classic Olive that everyone thinks of.

River Don - Large Dark Olive

Now this is a fly that hatches from March to October and there is a variation in size as the season progresses.

The early flies are usually a size 12 and sometimes even a size 10, and as the season goes on the flies get smaller, but will still be found hatching throughout the day.

By September the LDOs are down to a 14 and 16 in terms of size, but they don't seem to loose any of their appeal to the fish.

It is a fly which hatches from around 11am right through until 5pm on most days, although the peak of the hatch will coincide with the warmest part of the day, and it is a solid 1-2 hours of sustained emergence.

River Don - Large Dark Olive

It can be readily identified by its dark olive colouration, with a pale straw coloured underside, it has greyish main wings and really small hindwings with two tails.

Males will have larger eyes than the females, but the body colour is essentially the same.


Traditional: Greenwells Glory, Olive Quill, Blue Quill, Kites Imperial.

North Country: Snipe and Purple, Waterhen Bloa, Hares Lug and Plover, Dark Watchett.

Sandy's Fly Box: DHE, Plume Tip Dry, CDC Spider.

The March Brown

River Don - March Brown

The March Brown is the second main fly of the season and is one of the bigger insects. This is a Stoneclinger nymph and it is found in the more rocky stretches of the river. It is one of the few Stoneclingers that actually hatches at the water surface.

This is a large fly, normally a size 10, or even an 8, although a size 12 imitation will sometimes prove a better choice as the fish can often shy away from the larger naturals.

The March Brown is a fly that when it is hatching the trout will often ignore and appear to be avoiding, then suddenly they will start taking them and you can have some of the best dry fly sport of the season.

It is an easily recognisable fly with mottled brown wings with a distinct clear patch on the mains, it has a large mottled hindwing. The body will appear as a dark brownish, almost purple upper body, with an orangish yellow underside. It has two large mottled tails and dark legs.

River Don - March Brown

You will find the fly on the water from mid March through to around early May. It usually hatches in a distinct 2 hour window, usually from 12-2pm, give or take an hour depending on the weather.


Traditional: March Brown, Adams, Grunter, Jingler.

North Country: March Brown, Hares Lug and Plover, Partridge and Orange.

Sandy's Fly Box: Split Wing Emerger, DHE, Plume Tip, CDC Spider.

The Olive Upright

River Don - Olive Upright

The Olive Upright is a close cousin to the March Brown and is a similar size. The nymph is a Stoneclinger and it is found in the streamier bits of water, like the March Brown.

It is an elegant insect and has a brown/olive upper body and pale yellow underside. It has grey wings with a large hindwing and like the March Brown appears to hatch at the river surface. Two large greyish tails and pale legs.

River Don - Olive Upright

This is a fly that seems to be a particular favourite of the larger fish and often provides the best big fish, dry fly action. A size 12 would be the norm, but they can be as large as an 8 and as small as a 16.

The fly usually starts to appear towards the end of April and the hatches last until mid June. The first flies of the season tend to be the largest ones and as the weeks progress the flies get smaller and often get lighter. The smaller size 16 Olive Uprights can often be rusty orange-ish rather than olive, but they retain the yellow underside.

River Don - Olive Upright

The fly can be found hatching mainly around the midday period, but as the weeks go on it gets later in the day, and come June, you can find the smaller Olive Uprights hatching well into the evening. It is generally a steady hatch when it is on and the fish will key onto them pretty quickly.


Traditional: Greenwells Glory, Olive Quill, Blue Quill, Olive Upright.

North Country: Waterhen Bloa, Hares Lug and Plover, Partridge and Yellow.

Sandy's Fly Box: Split Wing Emerger, DHE, Plume Tip, CDC Spider.

The Iron Blue Dun

River Don - Iron Blue Dun

The Iron Blue dun is the smallest of the Spring upwings, it is an agile darter and hatches at the surface. It is also the darkest of any of the upwings and can often appear almost inky black on the water surface.

Up close, it has a very dark claret/brown body with a grey underside, with two pale grey tails and dark slate grey wings. It has a tiny hindwing that is extremely hard to see.

The fly itself is usually around a size 14-18, a size 16 is pretty much the perfect size. It is a fly that often hatches alongside the LDOs and March Browns and often in the worst weather conditions. They will continue to hatch throughout the afternoon and into the evening.

River Don - Iron Blue Dun

The trout will often take the Iron Blue to the exclusion of any other insect, so when you can see LDOs and March browns yet the fish don't want to rise to an imitation of either, then take some time and look to see if there are any inky little boats in the mix.


Traditional: Iron Blue Dun, Blue quill, Grey Duster.

North Country: Snipe and Purple, Dark Watchett, Black Spider.

Sandy's Fly Box: Plume Tip, CDC Spider, Down Wing Emerger.

The Large Brook Dun

River Don - Large Brook Dun

Large Brook Duns appear towards the end of May and into June, this fly looks like a really big March Brown at first glance, however up close there are quite a few differences. The wings are Mottled, but don't have the clear patch and have a slight yellowish/green hue. It has a large mottled hindwing and two long mottled tails.

The body is an olive/brown colour with purple wedge shapes on each segment. The underside is yellowish with a reddish centre line. It has longer legs than most upwings and when it holds it's wing slightly open it looks quite ungainly on the water.

They usually have a large flat head with dark green eyes. The Stoneclinger nymph crawls to the edges of the river and will climb rocks and reeds to hatch.

River Don - Large Brook Dun

Occasionally they will hatch at the water surface and when they do the fish will take them readily. The Large Brooks are always later than the March browns, so it could be that the fish take them from memory of the March Brown hatch, which would be finished. The takes can be particularly aggressive.


Traditional: Adams, Grunter, Jingler.

North Country: Hares Lug and Plover.

Sandy's Fly Box: Split Wing Emerger, CDC Spider.

The Yellow May

River Don - Yellow May

The Yellow May, as its name suggests, usually appears around mid May and tends to hatch in small numbers, so it is not often that you will see many flies on the water at one time.

It will continue to hatch right through the summer until august and can be both daytime and evening hatches. On a day when there are a good number of Yellow Mays hatching the trout will target them, this is often in specific localised areas , but can be a good hatch if you find one.

Another Stoneclinger nymph that lives in the rocky streamy sections, it hatches at the surface and will often drift for a while so can be a good fly at the tail of a pool. Unmistakeable in appearance this fly is usually a size 12 or 14 and has a canary yellow body with a paler underside, the thorax often appears pinkish orange and the wings are a soft yellowish colour with yellow veining and it has large similar hindwings.

River Don - Yellow May

It has two pale yellow cream tails. The males tend to be a stronger yellow than the females, which can be almost vanilla in colour.

Occasionally you may see Yellow Hawk Duns, these are a really short window hatch and only last a couple of weeks and will be very localised. The Fly is similar to the Yellow May, with darker wings and dark coloured tails. The same artificials will do the job.


Traditional: Tups Indispensible, Badger and Yellow.

North Country: Partridge and Yellow, Poult Bloa.

Sandy's Fly Box: CDC Spider, Plume Tip Dry.

The Small Dark Olive

River Don - Small Dark Olive

Small Dark Olives are the first of the summer time Upwings and from mid June through to August they will hatch all day and well into the evenings. They can be very small, from a size 16 right down to a size 20 and they come in a fairly wide range of colours.

This is an Agile Darter nymph and like the LDO it is found widespread throughout the river in rocky and weeded areas. The wings are a very pale grey and the miniscule hindwing is barely noticeable on a fly this small.

River Don - Small Dark Olive

It generally has a pale olive body with a yellow underside, although this can vary from a darker olive to a rusty brown depending on the time of year and where in the river you are seeing them. Two pale grey/cream tails and light coloured legs make it a relatively light looking wee fly.


Traditional: Greenwells Glory, Olive Quill.

North Country: Poult Bloa, Waterhen Bloa, Partridge and Yellow.

Sandy's Fly Box: Down Wing Emerger, CDC Spider, Plume Tip Dry.

The Danica Mayfly

River Don - Danica Mayfly

The Danica Mayfly is the largest of the Upwings you will find on the Don. It can be very localised and you will only find it in areas where there is a softer river bed, as it is a silt crawling nymph. Some of the slower sections of the river allow the silt to build up and in these areas you will find the Mayfly.

From around mid June through to July you can see these huge insects emerging at the surface in small numbers during the day. It is often a size 4 or 6 in terms of actual size and because they are never in huge numbers the trout don't pay them much attention, although if there is a small hatch then the bigger fish will notice.

River Don - Danica Mayfly

This fly has a large creamy/vanilla body with a couple of darker segments at the tail end, it has three long dark tails and has a veined wing with a large hindwing. The wings look yellow from a distance and this is the giveaway when you see one hatching, but up close the wings appear more clear with some black marks.

It is a very distinctive fly but may be confused with the Brook Dun from a distance when they are on the water.


Traditional: Mayfly patterns.

North Country: Hares Lug and Plover, Partridge and Yellow.

Sandy's Fly Box: Split Wing Emerger, CDC Spider.

The Blue Winged Olive

River Don - Blue Winged Olive

Blue Winged Olives start to appear as a late afternoon and evening hatch from around late June. The hatches will last until September and they will hatch in huge in numbers.

This is an important fly in a trout's diet and it can provide a lot of the sport during the summer.

The BWO nymph is a Moss Crawler and it tends to prefer vegetation on rocks and logs for a habitat, although you find them throughout the river and it hatches at the river surface in large numbers.

River Don - Blue Winged Olive

The fly is easily distinguished from the other olives by the fact it has three dark tails.

It has a medium grey wing with a medium sized hindwing, which often looks round in shape.

The body is an olive colour and it can vary from quite a bright greenish hue to dark olive and even a rusty dun colour, with a lighter coloured underside.

River Don - Blue Winged Olive

It can vary in size from around a size 14 to a 22, but generally it is a size 16 or 18 imitation that will suffice.

Of all the adult spinners, this one is the one the fish will target most readily, especially late evening and early morning.


Traditional: Blue Winged Olive, Grey Duster, Sherry Spinner.

North Country: Dark Watchett, Waterhen Bloa, Partridge and Orange.

Sandy's Fly Box: CDC Spider, DHE, Downwing Emerger, Plume Tip Dry.

The Large Green Dun

River Don - Large Green Dun

The Large Green Dun is a summer hatching insect which is quite similar to the Large Brook Dun, but significantly smaller, being around a size 12.

It is has a pale yellow/green body with small purple wedge shapes on the segments and red spots on the pale cream underside.

The wings are mottled and heavily veined, with a large hindwing and two dark tails.

River Don - Large Green Dun

This is a Stoneclinger nymph, which crawls to the edges to hatch on rocks and reeds.

Despite being quite an obvious daytime fly during the summer, it doesn't often get the fish going.


Traditional: Greenwells Glory.

North Country: Waterhen Bloa.

Sandy's Fly Box: CDC Spider.

The Caenis

River Don - Caenis

Caenis, the ubiquitous anglers curse, a silt burrowing nymph that you will find hatching in huge swarms in the slower reaches of the river on a summer evening.

The flies are tiny, size 20-26, and are almost pure white, with three short white tails and an orange/brown thorax.

The wings are white too, and this is the only upwing fly that will tend to hold them out flat all the time.

River Don - Caenis

When the fish key onto the Caenis, things can get extremely frustrating, but not impossible.

They tend to swarm, and you will find yourself getting covered in the little snowflakes. The Spinners are black with very long tails.


Traditional: Caenis.

North Country: Black Spider.

Sandy's Fly Box: APT, Spent Spinner (cream).


River Don - Spinners

Spinners are the final stage of the Upwing flies life, this is the sexually mature stage after the flies moult from Duns into Spinners.

The insects dance in the air, rising and falling while they perform their courtship routine.

For most species this occurs away from the water surface, the females then return to the water to lay their eggs.

After the courtship the male dies, often away from the river, the females will stay on the water surface after laying their eggs and this is the stage the trout love.

Female Spinners of most species are a rusty orange colour, the Iron Blue Spinners are claret and the BWO can be a darker orange/red colour.

The size of the Spinners is the only real difference as the season goes on and match the size to the species that have been on the wing.

The flies when dead, will lie flat in the water surface and can be difficult to see, although the current will often push them to sides of the river, so many Spinner feeders are found close to the bank.

The BWO Spinners tend to do their courtship dance over the edge of the water, so they are one of the few species where the males will fall to the water as well.

Many male Spinners are clear bodied, with a rusty coloured thorax and end segments, so are even harder to spot in the water.

River Don - Spinners


Traditional: Sherry Spinner, Ginger Quill, Rusty Spinner.

North Country: Partridge and Orange.

Sandy's Fly Box: Orange Spent Spinner, Cream Spent Spinner.

More key fly life to keep an eye open for.

Sedges / Caddis

River Don - Sedges

The Sedges are a large part of a trout's diet on the river, both in nymphal form and the adults. The fish often take the Sedge as a pupa when they are ascending the water to hatch.

There are a huge number of species which hatch during the year, starting with the Grannom, a daytime hatch in April and May. Grannom are small, around a 14, and have dark wings and a greenish body, they appear in swarms and the fish will often be more pre-occupied with the pupa.

Small Black and Brown Sedges which are around a size 16-20, have either brown wings or black wings, a dark greyish coloured body and small antenna. These can hatch all day and into the evening.

River Don - Sedges

Medium Brown Sedges have long antenna, a tan wing, a lighter grey body and are around a 12-14 in size. The Welshman's Button is a very similar looking fly.

Silver Sedges have long antenna, are around a size 10, with transparent brown wings and a light grey body.

The evenings from June onwards bring the Marbled Sedges, large flies of around a 10-12, with a mottled wing and a grey body.

Sandfly Sedges are also a size 10-12, they have a light tan wing and a greenish grey body.

River Don - Sedges

Later in the year the Caperers will appear, these are a size 8-10 and have a tan transparent wing over a tan/grey body.

The Cinnamon Sedge is around 6-8 in size and has light tan wings over a tan/grey body.

On an evening there are many species of micro sedge, these can be 20-24 in size and despite the variety, most are much the same basic size and colour.

River Don - Sedges

Despite the variety of the flies, the imitations don't need to be complicated, as they are mostly a similar profile and body colour.


Traditional: Wickhams Fancy, CDC and Elk, Deer Hair Sedge, Invicta.

North Country: Light Silverhorn, Yellow Owl, Winter Brown.

Sandy's Fly Box: Sedge Emerger.

Caddis Nymphs

River Don - Nymphs

The nymphs come in three forms, the Hydropsyche free swimming cream coloured nymphs, the Rhyacophila free swimming green coloured nymphs, and then the case builders, which you will see in all sorts of sizes on the river bed and attached to rocks.

The trout do like Caddis larva and many of the Czech style patterns imitate these really well.

River Don - Nymphs


Czech Style Nymphs in cream and green.

Cased Caddis patterns, Gold Head Hares Ear Nymphs.


River Don - Stoneflies

There are many species of Stoneflies on the river, but they are of little interest to the angler as the fish don't really take any of them.

Very occasionally, a skittering Stonefly will stimulate a fish to rise, so it is worth having something in your box, just in case.


Traditional: Stimulator, Wickhams Fancy, Turks Tarantula.

North Country: Spanish Needle, Dark Spanish Needle.

Sandy's Fly Box: Large Sedge emerger.

Alder Flies

River Don - Alder Flies

The adult insect appears around May and can seen until late summer, especially around the weeds and margins.

They lay their eggs on leaves and the larvae drop into the water and burrow into the silt. The nymphs crawl to the bank to transform into adults, so are seldom seen by the fish.

The adult is very much like a Sedge, but has very short antenna and smooth brittle wings rather than soft fuzzy ones. The fish will take them if they are around in numbers, but it is an unusual occurrence.


Traditional: Wickhams Fancy, or any dark palmered Sedge pattern.

North Country Spider: Spanish Needle, Brown Owl.

Sandy's Fly Box: Large Sedge Emerger.


River Don - Terrestrials

Terrestrials come in all shapes and forms, Hawthorn flies, Beetles, Aphids and small black Smuts are the most common, along with Cow Dung flies.

The Hawthorn fall in late May can provide some spectacular sport.

Windy days will often deposit quite a few terrestrials on the water and the fish will target them.

Sometimes a fish that is feeding close to the bank will only look at something unusual like a larger terrestrial.

River Don - Terrestrials


Traditional: Hawthorn Flies, Black Gnat, Cow Dung, Black Pennel.

North Country: Black Spider, Black and Peacock Spider.

Sandy's Fly Box: APT in small, large with legs, and in olive.

Further Reading

Sandy's River Fly Box

Now we have an idea of what we might find on the river, let's move on to: Sandy's River Fly Box.