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A South African dragonfly nymph imitation

By Fred Steynberg and Mario Du Preez

Dragonflies differ from most other aquatic invertebrates in two important respects: first, they usually have a much longer life span, and, second, they are normally much larger in size (during similar phases of development). These characteristics, coupled with the fact that dragonfly nymphs are very vigorous predators, enhance their levels of exposure, as well as appeal, to yellowfish and trout. The abovementioned differences between dragonfly nymphs and other aquatic insects, as well as stomach pumping exercises carried out on trout caught by the authors, verify the status of dragonfly nymphs as a major target for, especially, cruising trout and yellowfish in rivers and streams.  This article presents a short overview of the dragonfly life cycle, the dragonfly nymph anatomy, the most important families of dragonflies found in South Africa, and a description of the materials required and tying procedures for impressionistic, South Africa-specific, dragonfly nymph imitations.

The true dragonflies (Anisoptera) and damselflies (Zygoptera) comprise the suborders of the order Odonata. The Latin name for the dragonfly is broken up into aniso, which means “asymmetrical”, and ptera, which means “wings”. The “asymmetrical-wings”-description refers to a distinct anatomical feature – the discrepancy in size between the insect’s fore and -hind wings – the forewings are narrow and the hind wings are wide.

Not unlike the damselfly, the dragonfly has an incomplete life cycle, which consists of three stages, namely the egg stage, nymph stage and the adult stage. The life span of the dragonfly nymph, its water breathing stage, varies in duration, and can be anything from two to four years depending on the specific species. Dragonfly nymphs occupy a habitat which could include aquatic vegetation, stones and rubble, or submerged tree stumps and branches. In comparison to mayflies, caddisflies, stoneflies and midges, these insects are not found in vast concentrations in the specific areas they inhabit.

A dragonfly nymph moves by means of a very unique mechanism – it takes water into its system via an anal breathing and propulsion valve (situated at the end of the abdomen) and ejects the water out quickly, which propels the insect forward in short bursts. Dragonfly nymph movement is not restricted to sudden darts, but also includes crawling. As was mentioned above, dragonfly nymphs are effective and active predators that feed on any smaller aquatic invertebrates as well as small fish. The lower lips, also called ‘masks’, of the dragonfly nymph are modified to allow them to fold open to catch prey. As with the damselfly nymph, closer inspection of the dragonfly nymph reveals a lower lip that lays tucked back under its head. As adults, dragonflies hunt on wing in a hawk-like fashion or they wait in ambush to attack passing prey that includes a range of insects smaller than themselves.

Adult dragonflies are able to fly up, down, forward and backwards in quick bursts and according to Warick & Michele Tarboton’s handbook “A field guide to the Dragonflies of South Africa” they can reach speeds of up to 70km/h.

The mature dragonfly nymph crawls out and up on aquatic vegetation or other structures next to the stream bank, where it emerges into the adult. During their migration to the shoreline trout do target them, although the number of migrating dragonfly nymphs is small in comparison to that of migrating damselfly nymphs.

The common physical characteristics that define the anatomy of all dragonfly nymphs include: an abdomen thick and triangular in appearance; a very short thorax (narrower than the abdomen); a short head on which a large pair of compound eyes (almost touching each other) and two front facing, short antennae are located; wing pads overlapping the upper thorax and abdomen; and three pairs of legs situated along the thorax.

Although dragonflies and damselflies form part of the same order of insects, they do exhibit fairly different body profiles. Damselfly nymphs have thin, cylindrical bodies whereas the bodies of dragonfly nymphs are generally stockier in appearance. Moreover, dragonfly nymphs do not have any gills situated on the outer surfaces of their bodies, whereas the damselfly nymphs do (the tracheal gills situated at the end of the abdomen).

There are four families of dragonfly found in South African rivers and streams namely, Aeshnidae, Gomphidae, Corduliidae and Libellulidae. Of the aforementioned families, the Aeshnidae and Gomphidae families are found most often, during seine netting exercises performed in the rivers and streams of the North Eastern Cape. The Aeshnidae (‘swimmers’) family exhibits a body colour ranging from green, brown to black. This family of dragonfly has a very distinctive body shape compared to the other families found in rivers and streams: the body is longer with a very definitive taper.

The Gomphidae (‘burrowers’) family of dragonfly is brown coloured and their body profile is shorter and more oval in appearance compared to that of the Aeshnidae family. The Corduliidae and Libellulidae (‘crawlers’) families also exhibit body shapes that are short and oval and their bodies are also mainly brown in colour, and as such, are easily confused with the Gomphidae family. The relative similarity among the body shapes and colouring of the Gomphidae, Corduliidae and Libellulidae families allows the fly tier a measure of leeway: he or she only has to tie one generic pattern which emphasizes the abovementioned similarities or trigger points.

We have, however, included three imitations below, which covers swimmers, burrowers and crawlers.

The dragonfly nymph imitations shown in the photograph above are neither suggestive nor exact, but are impressionistic, and require the following materials:

Aeshnidae (swimmer) imitation:

Fish deep in still waters and use a fast or slow hand twist retieve with intervals. Fish in rivers and streams using a Leisenring lift in slow pools or drag free in currents.

  • Hook:             # 12-6  2-3X long nymph or streamer hook
  • Weight:           Optional
  • Eyes:               80-100 lbs burend mono fillament
  • Abdomen:      Black, brown or olive chinelle or wool under body dubbed over
  • Tail:                Black, brown or olive marabou (optional)
  • Thorax:           Black, brown, olive Squirrel dubbing with seals fur mix
  • Wing case:     Swiss straw or rafia
  • Legs:               Brushed out seals fur or rubber legs or thin round rubber

Gomphidae(burrower) imitation:

Fish deep or as close as possible to the bottom in freestone rivers.

  • Hook:             # 12-10  2X long nymph hook
  • Weight:           Lead wire
  • Eyes:               80-100 lbs burned monofilament
  • Abdomen:      Olive or light brown chenelle
  • Tail:                Marabou (optional)
  • Thorax:           Squirrel dubbing with seals fur
  • Wing case:     Rafia or Swiss straw
  • Legs:               Brushed out seals fur

Corduliidae and Libellulidae imitations (crawler)

Fish very slowly over weed beds in still waters (the deer hair helps keep the fly boyant).

  • Hook:             #12-8 nymph hook
  • Weight:           none
  • Eyes:               80-100lbs monofilament burned
  • Abdomen:      Brown or olive spun deer hair
  • Tail:                Marabou
  • Thorax:           Squirrel dubbing
  • Wing case:     Raffia or Swiss straw
  • Legs:               Mottled rubber

Fishing method

Dragonfly nymphs spend 99 % of their time crawling around on the river or still water bottom or on some form of water plant or structure in the water. The crawling movement is very slow and because it is on a structure, it is hard to imitate as the fly snags especially if a weed-guard is not incorporated. It is only when fleeing from danger or when attacking prey that the nymphs generally move by ‘jet propelling’ themselves. This quick darting action can be imitated in slow deep pools or in still waters by using a quick hand-twist retrieve interspersed with intervals, which allows for the simulation of rest periods, and/or for the fly to achieve depth before resuming the action. This method attracts fish or triggers a reaction, but often a very slow retrieve,which hardly moves the fly, or a dead drift in slow moving water or in water where currents are absent, works just as well and attracts the interest of, especially, larger fish that are looking for a vulnerable, big morsel such as this. A method that is often successful in slow, deep pools in streams when using these imitations is the ‘Lisering lift. The lift would resemble a fleeing nymph and often trigger fish.  A long leader is essential and no strike indicator is used.

One of the most effective methods in stronger currents or in flowing water is still just casting it upstream and drifting it down with the current, drag free. This resembles a nymph that has lost its footing in the current and is now drifting down until it reaches a spot were the current in not too strong to fight.

These patterns are suggested imitations and work well if fished correctly. There are, however, many other effective imitations that could be copied or bought.

A South African dragonfly nymph imitation2022-10-21T11:27:23+00:00

Knot Sense – Fred Steynberg

One of the most important components of terminal tackle is the knot that one would choose for a specific application.

Often when fly fishing in the salt with smaller flies for fish species that have extremely abrasive jaw bones and gill plates such as Tarpon, or for Giant Kingfish that lurk around coral bommies and reefs, it is necessary to use heavy tippet material.

Many knots can be used to attach a fly to thick shock tippet (80-120lbs) but not all knots finish off to the standard required to make the fly appear as natural as possible. Choosing the correct knot for the job could improve the strike and catch rate of targeted species drastically.

One of the essential knot criteria is to tie a knot that will allow the fly to move freely in a permanent loop created in front of the hook eye. A couple of knots can perform this task but when using thick, hard shock tippet the knot becomes bulky and often does not set straight, causing the fly to swim off-centre.

It is of primary importance to choose a knot that is at all times the strongest and allows for the least amount of weakening in the tippet as possible but when fly fishing using very strong shock tippet, the knot is of lesser importance. Even if 100 lb shock tippet, for example, loses 40% (although hardly ever this much) knot strength the remaining 60% (60lb) will be much stronger than any other part of the fly setup. In any event if a class tippet is not incorporated into the leader (making it the weakest point) to protect the rod or fly line then the rod will be the first to break if too much pressure is exerted on it.

It may be important to understand that when fishing in the salt for large and to powerful fish species that there are limitations to any fly fishing outfit and there are some considerations that need to be made.  Most fly lines above 8 weight have a breaking strain of between 35 and 45 lbs and a good strong backing is about 30-50 lbs. The fly rod can only handle limited pressure on either side of the rod tip, for example an average 10 weight fly rod can exert 9-11 lbs of pulling pressure, an average 12 weight about 11-13 lbs and a good 14 weight 13-15 lbs. This may sound ridiculously little but if you doubt this, attach the tippet of your preferred rod reel and line onto a boga grip and pull as hard as you think the rod can and you will soon realize that there is a correlation between the weight (line weight) of a fly rod and the amount of pulling pressure it can exert.

The leader, if built according to IGFA standards, or just to protect the rod, should consist of a butt section, class section and shock tippet and will then be the weakest point in the set up. The butt section is usually quite thick (30 – 50 lbs, depending on circumstances) because it is a continuation of the fly line and will help to transfer energy from the line up the leader thus opening up the leader for presentation or extra distance. The class tippet, normally attached with the bimini twist on either end to the butt and shock tippet/section, should then in essence be less than the breaking strain of the rod if its primary goal is to protect the rod.

Yes, I know, it does not make sense because the mere thought of hooking a large GT on a 12W using 10-12 lb class tippet is confounding, but it can be done, in fact 50+lb fish are often hooked and landed on conventional tackle using tippet a lot less than 12 lbs. Most of us, however, take a short cut, skip the butt and class tippet/sections and fish with a level monofilament (or fluoro carbon) leader from the fly line to the fly. This method has its advantages such as minimizing time spent building leaders, strengthening the leader (protecting it from sharp scales on the lateral line, tail slapping and numerous under water obstacles) and improving the handling of the leader when the fish needs to be landed. Disadvantages are as mentioned, a fish cannot be claimed under specific leader strength for IGFA and nothing protects the rod from snapping if things go wrong.

Then lastly the braided loop connectors that connect backing to the fly line and fly line to the leader are usually made from 30-50 lb butt section material (for large salt water species).

The point is that the weakest point in the fly fishing setup when using (80 – 120 lb) tippet/leader and losing a large percentage of tippet/leader strength due to the lack of knot strength, will not be in the leader. In other words a knot that does not have 100%  knot strength is not important but it should allow a reasonably small fly to move ‘free’ and straight without forming a bulky knot in front of the fly or hook eye.

A couple of knots such as the Non-slip loop, Surgeons loop and Homer Rhode loop create a loop in front of the fly and allow for maximum fly movement on thick shock tippet. The Non-slip loop (also referred to as the non-slip mono loop) works well on fresh water, thinner tippet material but leaves too much knot bulk on the thicker stuff. The Surgeons loop also leaves too much knot bulk and the loop often, especially when using thicker shock tippet, sets off-centre and the fly will then not swim correctly. The Homer Rhode loop is used by hardcore American salt rodders such as Lefty Kreh and is a good solid knot but at times difficult to set on tippet material above 100lbs and can also be bulky.

I prefer the perfection loop, a loop that often slips on thin 6X – 4X, fluoro carbon but has many good qualities on the thick stuff. This knot is strong enough and does not leave much bulk and most importantly allows the fly to swim in a straight line. The problem however, is to tie the knot/loop in a process normally used for loop to loop connections (and a simple process), so that the fly is incorporated within the loop. Tying a reverse perfection loop is an option but it needs practice and often the thick tippet makes the knot a frustration.

Before venturing onto yet another Tarpon excursion in January this year, I sat playing around for hours, trying to find a quicker and easier way to tie the Perfection loop.  I was amazed to stumble on a method that has me sold in believing that this knot is the best, simplest and quickest knot for the job. I am sure that similar and more simplistic ways to tie the perfection loop onto a fly have been developed and are in use, but the way explained below may be a help to anglers who have not yet come across such a method.

Below is a step by step guide on how to tie this knot.

Step 1. Create a large backwards loop and hold it in the left hand, the loop must be large enough for the fly to pass through.

Step 2. Place the fly on the tag end as demonstrated.

Step 3. Create a loop with the tag end to the front and around the back of the large loop and hold both loops between thumb and forefinger, with the fly locked in the smaller front loop.

Step 4. Bring the tag end, from right to left between the two loops and pinch between thumb and forefinger.

Step 5. Pull the fly through the large loop by grabbing it through the large loop with the thumb and forefinger of the right hand, entering through the back of the large loop.

Step 6. Pull on the line end of the leader until the desired size loop for the fly to move freely in has been created.

Step 7. Release the knot whilst pulling both the fly and line end of the leader and the knot will set.
Knot Sense – Fred Steynberg2022-10-21T11:27:10+00:00

Days that ants fly

By Fred Steynberg

This November, while guiding a couple of guys on highland mountain streams in Southern Africa, we came across a flying ant fall, this changed the course of the days fishing dramatically. We had begun fishing around 9 in the morning and because the water was high and the skies were slightly overcast and no fish were feeding off the surface we started prospecting with nymphs.  Nymphing is often the only real successful or productive method to target fish that feed off an abundant living drift, (living drift is the down-stream drift of invertebrates that for some reason, have lost their hold on the river bottom and are swept down the current to ultimately become fish food.)   In fact nymphing can be so productive that even the most well ‘fed’ fish in a natural stream will not refuse an imitation when fished correctly.  This day seemed no different from any other and we caught numerous Rainbow trout and a half a dozen large smallmouth yellow fish on nymphs.

By lunchtime most of the cloud cover had burnt off and a slight downstream wind developed.  Fish started rising on the odd occasion but we could not make out what they were feeding on as no insects were coming off or floating on the water surface (or so it appeared).  I changed my clients’ nymph set-ups to dry fly rigs and we caught and missed a couple of the rising fish on terrestrial patterns such as floating spiders. What we did not realize was that a flying ant fall was happening a couple of hundred meters upstream in the direction that we were fishing.   A few ants (that were hard to see on the water surface) had already started drifting down and this is what the fish were occasionally feeding on.   As we fished up-river the rises became more intense and the fish rising, larger.  We stared seeing mating flying ants in small clouds above us.

The queen ants were large, black and dark brown bodied with enlarged shiny abdomens while the males were less than half their size, blacker in colour and a lot slimmer.  Some of the ants had fallen on the water whilst still attached in mating mode, making the meal for nearby fish even  more irresistible.  I tied on a larger black floating, flying ant imitation on relatively long tapered leaders attached to 4X tippet.  The 4X tippet may sound like a slight over-kill but the fish were big, strong and were too frenzied to be tippet shy.

Left: the slimmer male ant. Right: larger queen ant

The nature of the smaller trout was to lie in one spot waiting for the ants to drift onto them while the Yellow fish and larger trout would swim around in larger pools frantically gulping up the ants.  The yellow fish would often turn short of the ant, creating a splash with their tails as they turn,  so close to the ant that it would ‘drown’.  The yellow would swiftly return to collect the now, sub-surface meal. The moving fish can make life difficult, under these circumstances, for an angler who may struggle to accurately present flies, but patience is rewarded.

We found a healthy wild trout of about 20’’ cruising off the current, feeding wildly.  One of the guys with me presented a flying ant imitation that fell well behind the fish.  The fish continued feeding away from the fly and after a couple of gulps disappeared.  The presented fly was still drifting on the surface when the angler turned to me asking if we had spooked the fish.  At that moment, as Murphy would have it, the trout reappeared on the surface, gently sipping the imitation off the top.  I shouted ‘yes’ as the fish disappeared and the angler instinctively struck, fortunately setting the hook.  Two lessons can be learned from this:  1. Never take your eye off the dry fly or strike indicator that drifts on the water and 2. When there are flying ants on the water surface fish don’t often stick to lies or their usual patterns.

As the fish felt the hook and line tension it dove straight down into the natural water grass of the deep pool and imbedded itself.  The angler had no choice but to swim in after it, not touching ground but eventually managed to free the fish and continue the fight.

Left: a wet angler with the good size wild trout, Right: fly in the vice

A couple of pools further upstream and a number of fish later we found a yellow fish female in a riffle lazily sipping ants off the surface.  She was quite large but had no other apparent competition. It was amazing to witness such a large fish methodically feeding of the surface.  Unfortunately we spooked some Yellows from the pool below the riffle and they shot up-stream alerting the big fish, pity because she would have been special on a dry fly.

Some flying ant info:

Flying ants or ants that fly and land up on the surface of the water are like manna from heaven to both indigenous Yellow fish and trout.  This phenomenon which we anglers call an ‘ant-fall’ is seldom witnessed as it does not happen often.  When however it does happen, fish will greedily react to the fall and will be on high alert, often lying close to the water surface to sip up the protein source that helplessly float down-stream.

Most ant species fly and the bigger the ant the more spectacular the reaction to the fall.  Predatory birds are often attracted to the feast and are a tell tale sign of the event.  The ant colonies do not communicate the flight but simply react specifically to temperature, humidity and wind speed.

Queen ants emerge from their nests and begin their nuptial flight with the smaller males in pursuit.  Some queen ant will fly long distances but others only a couple of meters from the nest.  They mate in the air after which they fall to the ground and lose their wings and attempt to start a new colony.

The flight is called the nuptial flight and many colonies of the same species can turn to flight simultaneously to minimize the effectiveness of predation.  This collective flight between many colonies of the same species will ensure that new colonies are formed and that old colonies have an injection of new blood ensuring its survival.

Many of the ants from both genders land up in the water, especially when losing focus during the mating process.  Flying ants are bad swimmers and once their wings get sucked onto the water surface they are doomed as the insect is too weak to lift them out.  I have often rescued individual ants from the water surface, for inspection, and as soon as they dry and become mobile they fly away.  Flying ant imitations have been around for ages and have saved many a day on the waters. Fish that are rising to floating ants will often not react to any other offering.  This can be frustrating to the ill prepared fisherman.

I always carry a handful of floating ant patterns in different shapes and sizes, with and without wings.  Travelling without flying ant patterns in your fly box is like going on a fishing trip with a medical kit that has no Imodium, you don’t often need them but if you do then you need it bad!

I have witnessed a dozen or more ant-falls in my life that have been close enough to the river to cause the ants to land up helplessly on the water surface.  The larger fish in that specific river often awaken from their steady side-to-side nymphing mode and move into the upper water column to intercept the ants.

Once many years ago, four or five large fish fed so frantically on flying ants off the surface that from a distance they appeared to be otters rolling and playing on the water surface.  Only when I moved closer could I make out the large trout feeding on the flying ants and what an amazing sight!

Left: a colourful Smallmouth Yellow from a riffle, Right: this 16’’ rainbow (cannibal) ate a 8’’ juvenile trout. The tail of the prey is still protruding from the predators mouth as the food source, partly decayed, was to large to swallow. This fish still accepted a # 14 bead-head hare and copper nymph

Nymphing down stream

Days that ants fly2022-10-21T11:26:54+00:00

South African Leptophlebiidae (prongills) nymphs

By Fred Steynberg and Mario Du Preez

Izaak Walton, in his classic work entitled ‘The Compleat Angler’ published in 1653, wrote the following about the trout’s favourite prey: “… and he especially loves the May-flie,” Many years later, Dave Whitlock (see ‘Guide to Aquatic Trout Foods’) unequivocally reaffirms the status of the mayfly by remarking that “Mayflies are the best known and most popular of all trout foods”. Gary Borger, in his mammoth work entitled “Presentation”, also describes mayflies as “…the insect group upon which modern fly fishing was founded.” Stomach pumping exercises, performed on trout caught inhabiting the rivers and streams of the North Eastern Cape, lend further credence to the astute observations of Walton, Whitlock and Borger. More specifically, the results of stomach content analyses, performed over more than 10 years by the authors, reveal that mayflies constitute, on average, in excess of 75% of the food forms found.

The Latin name for the mayfly order is Ephemeroptera and describes two things synonymous with the mayfly: the adult stage in the mayfly’s life cycle is short-lived (usually between one and two days in duration) and the adult is a winged insect. There are nine families of mayfly found in rivers and streams in South Africa. These include the Baetidae, Caenidae, Heptageniidae, Leptophlebiidae, Oligoneuridae, Teloganodidae, Tricorythidae, Polymitarcyidae, and Prosopistomatidae families. Of the abovementioned families, only the first seven are of importance to trout, and hence, the fly fisherman. The last two families, due to their behaviour and habitat choice, are seldom, if ever, targeted by trout during their nymphal phase of development.

This article presents a short overview of the Leptophlebiidae family’s life cycle, the Leptophlebiidae nymph anatomy, the Leptophlebiidae sub-adult (dun) anatomy and descriptions of the materials required and tying procedures for impressionistic, South Africa-specific, Leptophlebiidae nymph and sub-adult imitations. The Leptophlebiidae mayfly family is also sometimes collectively referred to as “prongills” and there are twenty known species in South Africa. The most famous species of this family mentioned in international literature include the claret dun, the black quill and the slate-wing mahogany dun.

from a scientific perspective (i.e. there is no pupal stage between the larva and adult stages). The life cycle consists of four distinct stages, namely the egg stage, the nymph stage, the sub-adult stage, and the adult stage. The two adult stages are unique to the mayfly – during the sub-adult or sub-imago stage the mayfly is sexually immature.

The life cycle of the Leptophlebiidae mayfly starts when the sexually mature adults (i.e. sub-adults or sub-imagoes or spinners) mate during flight, after which the males die and fall to the water’s surface or onto surrounding land. The female of this family lays her eggs by dipping the end of her abdomen into the water’s surface, whilst flying low over the river or stream. The eggs sink, and due to current movement, are scattered along the substrate and between debris and aquatic vegetation. Upon hatching, the Leptophlebiidae nymphs live on the river bottom in slow moving or still water areas, sheltering from predators and currents by hiding under stones and debris – these nymphs are also protected by their camouflage. The nymphs are capable of running across the substrate and swimming for short distances only. In British fly fishing circles these nymphs are referred to as ‘laboured swimmers’.  The nymphs feed on aquatic vegetation by removing algae and detritus from the undersides of stones and rubble.

The body design of the Leptophlebiidae nymph clearly reflects its specific habitat adaptation (i.e. slow moving or still areas in rivers and streams). The body exhibits the following physical characteristics:

  1. A head – the head, which is square in appearance, bears compound eyes on each side, with three simple eyes situated in between the compound ones, and two front-facing, short antennae;
  2. A clearly segmented thorax (three segments) – the thorax bears one pair of legs on each segment and a forewing pad on the second segment and a hind wing pad on the third segment (the wing pads give the thorax a ‘humped’ appearance); and
  3. An abdomen – the abdomen consists of ten clearly defined segments, of which four to seven have gills attached, and three, long, well defined, spreading tails are found on the final segment (the tails are longer than their bodies).

The tails of the Leptophlebiidae nymph are generally much longer compared to most other mayfly families found in South African rivers and streams – only the Heptageniidae family could possibly rival it in terms of tail length. The surface areas of the gills of the Leptophlebiidae family are large, since this nymph occupies the slow-moving or still water areas of rivers and streams, and as such, it must produce current in order to take in enough oxygen.  Each gill is split into two lobes and is either hair-like or leaf-like in appearance or a combination of both, depending on the specific species. The body colour of the nymph ranges from brown to dark brown. A reddish-brown body colouration is also occasionally found.

From a fly fishing perspective, the nymphal phase of the Leptophlebiidae family’s development is the most important stage to imitate. Since the nymphs of this family are generally quite large, trout love to target them, especially when they loose their footing and are washed away by faster currents.  Regular seine netting performed in the rivers and streams in and around the village of Rhodes has revealed a preponderance of these nymphs right throughout the year.

Once the Leptophlebiidae nymph has fully matured, in terms of growth and age, it will either crawl out of the water onto a rock or tree trunk/branch, or it will ascend to the water’s surface in still water areas, where it will force its way out of its nymphal skin and unfold into an air-breathing, winged sub-adult, called a dun. In the North Eastern Cape Province of South Africa, the most prolific hatches of the Leptophlebiidae family occur in the late season (April/May) and early season (September/October). The dun sits almost motionless on the tree trunk/branch, rock or water’s surface until its wings and skin have hardened and dried sufficiently, after which it flies to waterside vegetation. Here it transforms into the final life cycle stage, namely the sexually mature adult (imago or spinner). Although North Eastern Cape trout prefer the nymph imitation, they will prey on the dun. The spinners, on the other hand, are not of any significance – the authors have never witnessed a fall of Leptophlebiidae spinners on the rivers and streams of the North Eastern Cape. In the United States of America the spinner of this family is generally also considered to be of little importance.

The body design of the Leptophlebiidae dun closely mimics that of the nymph. The obvious differences include, the absence of gill filaments (these are replaced by a “tracheal tube diffusion network” – see Whitlock) and the presence of two pairs of upright, sail like wings (the forewings are noticeably larger than the hind wings). The duns are not very colourful and have a very drab look. They generally average between 7 and 12 mm in size and have medium to dark brown bodies (only the spinners have reddish-brown bodies), slate grey wings (sometimes heavily mottled), three brown tails and six, well defined brown legs.

The Leptophlebiidae nymph imitation shown in the photograph above is the one preferred by the authors – it is the very famous and popular Zak nymph originated by Dr Tom Sutcliffe.  What makes this pattern ideal is the dark appearance of the peacock herl used in the body construction and the long water mongoose or squirrel tail fibres used to simulate the tails. Moreover, the profile of the imitation, as required by the original recipe, also lends itself to the production of an impressionistic facsimile of the natural. The nymph imitations illustrated vary slightly in appearance and in tying method from the hardy original pattern tied by Dr. Tom, but works just as well. This imitation requires the following materials:

Hook: # 14 and 12 nymph hook

  • Bead: Optional, 2,3 – 2,6 mm gold bead on # 14 hook and 2,6 – 3mm on # 12 hook.
  • Thread: 8/0 Black
  • Weight: Optional but advisable, depending on the strength of the current.
  • Tail: 3 – 6 Squirrel tail, water mongoose or similar dark brown or black fibres the length of the hook shank or longer.
  • Abdomen: Three partly striped peacock herl
  • Ribbing: Copper wire and optional, 3- 4 turns of blue, copper or gold crystal flash
  • Thorax: Peacock herl
  • Legs (hackle): Sparse dark dun or black hackle

This imitation should be fished in the cushioned boundary layer just above the stream bottom, as deep as possible. It is not that the nymph necessarily drifts this deep but fish that avoid currents and lie within the cushioned boundary layer would rather accept a food source that drifts within range so that they do not exert too much energy reaching it.  The Zak may be tied with a couple of turns of crystal flash and with a gold bead (that acts as a trigger and a weight) as in the photos, for fast flowing streams but in clear low waters it is advisable to use less flash and at times even exclude the bead. When targeting fish in slow or no current areas a Leisenring Lift or even the occasional hump mend would lift the fly off the bottom and imitate a fleeing nymph triggering a reaction. When the Leisenring lift is executed it helps to wiggle the rod tip to create an erratic swimming action. When fishing these imitations in fast currents, drag free, it is necessary to fish up or up and across using a strike indicator for depth control and strike detection. Fish often sample imitations in strong currents and spit the fly after realizing that it is not the real thing, the indicator will warn the angler to strike as soon as possible to set the hook. When fishing in slow or no current areas and using a Leisenring Lift, it is often not necessary to use an indicator as the take will be felt and the drag of the indicator on the water surface may alert fish. For maximum results, use a long tapered leader with 5X tippet (double figure fish are often landed on 5x tippet) and insure that drag does not have an effect on the fly.

The Leptophlebiidae dun imitation shown in the photograph above was developed by Fred Steynberg specifically to imitate the duns of this family found in the North Eastern Cape. The pattern is neither suggestive nor exact, but is impressionistic, and requires the following materials:

Hook: # 14 or 12 thin wire dry fly hook.

  • Tail: Brown or black deer hair or water mongoose fibres.
  • Abdomen: Ring neck pheasant tail fibres or mottled turkey tail fibres
  • Wing: Mottled or partly bared brown deer hair fibres
  • Legs (hackle): Dark Brown or red-brown hackle, cut level so that the fly sits with its body on the water surface.
  • Thread: 8/0 Black or dark brown

This imitation should be fished with a drag free drift in the slow or fast moving current areas with a long leader and 5X tippet.

South African Leptophlebiidae (prongills) nymphs2022-10-21T07:40:08+00:00

Articles List

  • Articles List
    Articles List
    January 29, 1990
  • South African Leptophlebiidae (prongills) nymphs
    South African Leptophlebiidae (prongills) nymphs
    October 5, 2008
    By Fred Steynberg and Mario Du Preez Izaak Walton, in his classic work entitled ‘The Compleat Angler’ published in 1653, wrote the following about the trout’s favourite prey:...
  • Days that ants fly
    Days that ants fly
    October 13, 2008
    By Fred Steynberg This November, while guiding a couple of guys on highland mountain streams in Southern Africa, we came across a flying ant fall, this changed the...
  • Knot Sense - Fred Steynberg
    Knot Sense - Fred Steynberg
    June 9, 2009
    One of the most important components of terminal tackle is the knot that one would choose for a specific application. Often when fly fishing in the salt with...
  • A South African dragonfly nymph imitation
    A South African dragonfly nymph imitation
    April 24, 2012
    By Fred Steynberg and Mario Du Preez Dragonflies differ from most other aquatic invertebrates in two important respects: first, they usually have a much longer life span, and,...
  • Fly casting: a question of style?
    Fly casting: a question of style?
    June 6, 2017
    By Fred Steynberg and Mario Du Preez During the Master Instructor Certification Test conducted by the Federation of Fly Fishers (FFF) in the United States, candidates are required...
Articles List2022-10-24T08:31:15+00:00
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