High Energy III – Olive Mohair Leech

The Olive Mohair Leech is the first high energy potential fly I used. Mike Kruse introduced it to me, and it became a firm favourite as a great fish catching fly, as well as a very quick tie.

When I started out fishing I fished mainly with #16 Hare & Coppers. Hare and Coppers took a lot of fish, but the fly needed to be close to the fish for the fish to take it.

Fishing lake edges, backwaters and the back of long slow pools to cruising fish is my favourite form of fishing. It allows me to observe the fish closely, and see how they react to the fly.

The reaction to the leech is often extremely aggressive. If a fish spots the leech and decides to take it, it will charge the fly and hook itself. Sometimes the fish will charge the fly, refuse, look at the fly and refuse again before taking, so it is always worth staying in contact with the fly and watching for the fish to open its mouth.

When fishing still or slack water I often fish a #16 Hare and Copper about 2 ½ feet behind the Leech. A fish that refuses the Leech will often take the hare and copper as it swims away.

Note the distance between the flies, this serves two purposes. The first is that the flies are sufficiently far enough apart that the fish does not appear to think that the Leech it has just refused is linked to the Hare & Copper. The second reason is when fighting fish if the trailing fly foul hooks the fish during the fight the fly in the fishes mouth will often come out, and the fish can get away.

The Olive Mohair Leech represents damsel fly nymphs. In larger sizes it may also represent dragon fly nymphs. Both of these are large food sources, with far more energy potential than the waterboatmen and other small insects the fish are feeding on.

The Leech triggering a hyper aggressive response is a surprise to most anglers the first time they see it. Many years ago I was fishing with my brother Jack and a mate Gareth Gray at Lake Tutira in Hawkes Bay. We were taking turns to cast at cruising fish, and it was the first time Jack & Gareth had used the leech.

We were on a heavily treed peninsular when Jack spotted a fish cruising towards us. It was Gareth’s turn to cast to the fish, but for some reason Jack had his flies in the water already. Gareth was between Jack and the trout and put a couple of nymphs into the water with a bow and arrow cast.

The fish appeared to see the flies landed, and someone said “its spooked” when it had actually charged past Gareth’s flies and took Jack’s leech.


Hook:                     Kamasan B175 & B200 #10, B175 #12

Thread:                    Olive Unithread 6/0

Tail:                          Strung Marabou Olive not Woolly Bugger Marabou

Body:                                 Olive Mohair

Weight:                  0.20 lead wrap or 2.7mm tungsten bead

Tying Instructions

  1. If using a tungsten bead put flatten the barb of the hook and put the bead on.
  2. Wrap the hook with thread and tie in the marabou.
  3. Tie in the mohair yarn.
  4. Wrap with lead wire unless using a tungsten bead.
  5. Wrap the mohair yarn forward and tie off.

Tying Notes

  1. To get a bulkier body tease out the mohair yarn with your fingers as you tie it in.
  2. It is possible to use a dubbing needle to pick out the yarn once tied in but this is not as effective as teasing it out as it is being tied in.
  3. I have experimented tying the leech with my Nor-Vice, spinning the vice to tie in the mohair. This means the mohair is tied in a lot faster than if wrapping in by hand, and usually results in a fly that is narrow and not as rough as when I tie it without spinning the fly.
  4. Craft store mohair yarn is usually fluffier and a far cheaper than fly shop purchased mohair yarn.
  5. I prefer to use a short shank heavy gauge hook with a wide gape than a long shank hook with a small gape. When I first started fishing the leech I lost a number of fish on a #14 Kamasan B200, which has a narrow gape but is about the same length as a #10 Kamasan B175. I hate losing fish due to poor gear choice, so I stopped tying on the #14 B200.

Fishing Notes

The key to getting a fish to take a leech is to get the leech at the level the fish is cruising at in the water column before the fish sees the leech. This means having enough weight to get down relatively quickly, but not too much weight so the fly sinks to the bottom or looks far bulkier than a slim damsel nymph.

My experience has been that fish rarely take the leech if they see it land on the water, or if they have to come up in the water column to take it. A good presentation where the fly is at the same level of as the fish, and is put sufficiently far enough in front of the fish that it does not see the fly landing on the water has a good chance of getting a take.

From a tactical perspective I would far rather cast a good way in front of the fish and have the fish turn away from the fly before it sees it, than cast so close to the fish that it sees the fly land on the water or sees they fly before it has sunk to its level.

The retrieve that I have found consistently takes fish is a figure of eight retrieve. I learned this while fishing blind, when I missed a good number of takes when I was stripping the line in about a foot at a time. The takes were often when I had let the line go and was reaching forward to make the next strip. My connection rate when I was not holding on to the line was not good. A figure of eight retrieve kept me in much better contact with the fly and I had a much

Similar Patterns

The Leech is a very similar pattern to a Woolly Bugger and represents the same food as a Damsel Nymph tied with eyes and gills and a slim body. Others may like these patterns, but I prefer the leech for several reasons.

The Leech always swims right, which may not happen with a nymph with eyes that may come in on its side. I am always fearful that this kind of unnatural presentation will cause the fish to reject the fly.

Woolly Buggers are a fly that is far more popular than a Leech, but it takes longer to tie which puts me off tying it when the Leech works exceptionally well. I have always preferred the rough finish of the Leech over the tidier look of the Woolly Bugger.

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