The Blue Dun Flyfishing Dry Fly pattern has taken many trout for me, particularly early in the season. Trout have a great liking for this little fly. It is commonly believed that it hatches only on wet, windy days. This is not true as I have seen numerous hatches in calm warm conditions.
DRY FLY PATTERNS. Hook size 12 14 16 18 20 24 - $US each
It is easy to spot as it is the only upwinged fly that has such an overall dark body color. The Blue Dun hatches from early to late summer. Peaks may occur in May and at end of summer in September. It emerges on the surface in open water during the day in irregular, but sometimes prolific, hatches. The Blue Dun generally is not an evening fly thankfully as trying to imitate such a small dark fly in failing light would be a headache and impossible to see on the surface.. They tend to swarm during the day. Mating and egg laying also often takes place during the day.
In Britain this pattern is used to imitate the Iron Blue Dun. This fly is found throughout the British isles and is known by various different names such as Dark Watchet, Little Purple, Iron Blue Drake, Little Dark Blue or Little Dark Blue. The strange thing about this fly is that it undergoes a second moult in its winged stage and therefore a slight color and shape change during its life span. The dun is a poor flyer after it emerges. It is vulnerable to fish and birds so it normally rests for several hours or if the temperatures are low, over night on riverbank vegetation, shrubs or trees. When you are walking the riverbank it is always a good idea to turn over leaves and look in spiders webs to see what has been hatching.
The Iron Blue Dun is one of the smallest mayflies and is referred to as a 'lunch to teatime fly' as the hatches do not occur in the morning or evening. It is a river, not lake fly. The male and female Iron Blue Duns are very similar in appearance.
The last three segments of the male's abdomen in it's mature state turns a reddish brown whilst the rest turns a lighter pale colour. This is why you will see some patterns for sale with a small red abdomen. It is the egg laying female that is mainly eaten by fish and should by on the end of a fly fisherman's line most of the time not the male. Having completely dried out and rested after moulting you will see the males take to the air and swarm near the water. The females fly through the top of the swarm where they are clasped by a male and mating takes place on the wing. When they separate the female returns to the water and flies upstream prior to egg laying. She crawls underwater to deposit her eggs in the substrata. many females get trapped in the water surface tension when they return up to the water surface. Even those that manage to get airborne again fall exhausted back onto the water as spent spinners. They are then eagerly taken by hungry trout.
The amount of eggs that are laid depends on the size of the female which varies from species to species and time of year. Females hatching later in the season are normally bigger than those in the cooler months. Some of the larger females can carry over 2,000 eggs. This fly falls within the insect family grouping called Ephemeroptera. I hate these long latin names, don't you? This family or order is subdivided into eight different groups. One of these groups goes by the name of Baetidae. It contains nine different individual insects. Two of them look so similar that to the naked eye you could not tell the difference. They are Baeties niger and Baeties muticus. To you and me the Iron Blue Dun. The Baeties niger is normally found in Central and Southern England Chalkstreams, where as the Baeties niger is found all over the UK preferring faster flowing rivers with gravel beds
I live in London. If I am travelling around the countryside and see a car boot sale, auction or antique shop, I stop and check to see if there is any old fishing equipment on sale. When there is a death in the family, many people sell their relatives bits and pieces. I had a fascinating find last summer. It was an old fly wallet. Owner said it used to belong to his great granddad who had been a water bailiff. It was in a neglected condition. The black leather cover was about 7" x 4". Some of the hooks of the flies inside the wallet had gone rusty. A few flies near the exposed edges of the wallet had suffered from moth damage. I was delighted to find that many of the flies in the centre were still in a reasonable condition.
The wallet contained a number of pocket pages. The original owner had written notes about each fly, giving its name, and when and where to use it. There were three blue dun flies on the first page. The notes said March, the blue dun is found in every River known under a score of different names such as the olive dun. The earlier and colder the season, the more olive and dark it is. There was also a selection of March Brown fly patterns. The notes said March Brown also known as the cob fly Wales. This is a very useful fly, one of the best. Often comes on very quickly in many quarters. The female is lighter and yellower than the male. On next page there were more ancient flies that are still extremely popular. These included Wickham's Fancy, Soldier Palmer and gold ribbed hares ear. The list went on. These flies were nearly 100 years old. It was a great find.
Dry Fly Fishing on the River Test
If the famous "chalkstream" River Itchen in Hampshire is regarded as the queen of fly fishing rivers then the River Test must be arguably the King. It was along the banks of this wonderful fertile stretch of water, that once held such a variety of insect life, that dry-fly fishing evolved and became recognised as a most thrilling way to catch rising trout.
Through the 1800s to the 1900s notable gentlemen anglers cut their teeth on this river as they honed their expertise and developed the use of the dry fly. There was none more famous than Frederic Halford who for so many years fished and leased some of the many, now historical, river Test beats that provided him with the knowledge and information he recorded within his writings.
Halford promoted a chalkstream ethic of "upstream dry fly only to a rising fish" approach. This mantra established him so many years ago. It was rigidly adopted by many fisheries and upheld since by some fly fishermen today. Thankfully this dry fly only rule has changed.
Unfortunately the River Test, like so many other UK rivers, is suffering from a reduction in the volume of natural aquatic insects that have sustained the sport of dry-fly fishing over the years. Although many substantial trout are still taken on the dry fly these conditions have tended to increase the use of sub-surface fly patterns.
Access to quality fishing on the River Test, which for so long was only open to an exclusive few, has become more readily available so long as you can afford the price of a day ticket. Visitors can now test their skills on this historic river. To many fly fishermen even walking the banks of these hallowed waters can be quite daunting, let alone being able to fish them.
All you need is a 9ft 4-wt or 5-wt rod with a double taper line and a 12ft leader down to a 3lb tippet. Your choice of dry fly is dependent on what is hatching at the time you have chosen to go fishing on the Test. I normally choose flies in a hook size of 16 or 18.