The Mountain Dam Midge is not so much a pattern but a process I developed in conjunction with Alan Hobson whose pioneering work on Somerset East’s municipal dam will, I believe, substantially increase catch rates in future for those who fish dams for trout and yellowfish.



Alan Hobson – the Midge Maestro of Mountain Dam

In essence it comes down to the fact that both species in an environment where they have ample opportunity to examine patterns without the need to fight currents, take micro-patterns with less suspicion than big flies.

Until recently, micro-pattern hooks were manufactured with fine wire and small eyes but all that changed when Gamakatsu brought out the #26 C12 BM big eye midge hook. Other hooks such as the #22 Ahrex 507 (which you can order through Craig Thom at Stream-X) and the #24 Allen N304  offer similar medium wire and big-eye advantages, albeit in slightly larger sizes

I can now tie such small patterns with ease (provided I use my Optivisor headband magnifier) and my Eureka moment came when I used the finest thread on the market, UNI-Caenis and when UV light-cured resins became available.

You can’t pull on the bobbin to extend this thread as you normally do, you have to unspool the thread with your thumb and I use Mucilin or Vaseline on the contact points between the bobbin and my favourite bobbin holder to minimize tension on the thread.

I keep a Stonfo Elite bobbin threader handy because you will break this thread from time to time but it has the advantage that it does not immediately unravel on the hook and you just re-tie the thread and continue.

The MDM is constructed in two sections.

The back half consists of extra-fine silver Semperfli or UTC wire which I wind on in spaced turns using a Stonfo Bobtec bobbin because it gives me greater control.

The back of the hook is covered with a tiny dab of superglue applied with a toothpick.

The wire adheres to this and can then be broken off.

Then a layer of Loon Fluorescing UV Clear Fly Finish mixed with black glitter dust (obtainable from PNA stationary shops) is applied to cover the wire and cured. Over this is applied a layer of more viscous UV resin. The Loon resin gives the fly a blue glow and the glitter dust shines through the upper layer of UV resin.

(Solarez now offers resins with built-in glitter particles such as Topaz Sparkle.)

Attach your thread in the gap between the body and the hook eye and tie in your wing.

This can either be Fishient Gliss ‘n Glow Clear Ice which has a very realistic serrated finish or pearl Micro-Crystal Flash pointing backwards or paper-thin ethafoam packaging material pointing forward over the eye. Gary LaFontaine advocated ethafoam because of its light-dispersing qualities.

Cover the tie-in point of the wing with dubbing to create the head of the fly.

I favour Hareline Quick Descent Dubbing which is made of ultra-fine aluminium shavings because nothing beats it for constructing micro-pattern bodies. The late Shane Stalcup favoured this material in silver because he believed it  imitated the silver air bubbles which cling to emerging aquatic insects.

You could also use the fuzz stripped from a peacock feather and applied to waxed thread to cover the wing tie-in point and to mimic the head of the insect.

If you find the thought of such small hooks and such fine thread intimidating then you can use Frontier Fly Fishing’s Tiemco 2499SP-BL in # 18 or Upstream’s Dohiku 302 N in #20 both of which can be matched with stronger but still fine threads such UTC 70 or Semperfli 18/0 Nano Silk or Veevus 16/0 or Uni-Trico 17/0 which Gordon van der Spuy favours, but which is only available in white.

In the illustrated tying sequence below I used the #24 Allen N304 hook for the first three photographs and the fourth photograph shows the #26 Gamakatsu big eye hook with a wing of pearl Micro Crystal Flash. The third photograph shows the effect of using Solarez Blue Topaz UV resin rather than adding the glitter dust yourself. The pattern in the final photograph uses a #22 Ahrex 507 hook.


The silver wire is wound on to the hook shank after it has been covered with superglue


The wire is covered with Loon Fluorescing UV resin which glows under UV light.


The blue glints created by the second coat using Solarez Topaz Sparkle UV resin.


A Mountain Dam Midge using black glitter dust mixed with the bottom layer of Loon Fluorescing UV resin.


A Mountain Dam Midge tied on a #22 Ahrex F507 hook and using silver Quick Descent Dub and doubled ethafoam at the hook eye. The internal glitter dust gives the fly a mottled appearance.

I believe Alan Hobson will redefine our approach to dam fishing for trout and yellow fish. His research into the role of predacious diving beetles in the diet of these species stands alone and he is, as far as I can ascertain, the only person tying commercially-available imitations of the of the Phantom Midge (Chaoborus) larvae – also known as ‘Glassworms’ which is a staple in the diet of dam fish – something that was reflected in the CPS journal, Piscator, six decades ago.

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