[Video] Tying Frank Sawyer’s Killer Bug by Davie McPhail

Davie McPhail demonstrates how to tie Frank Sawyer’s Killer Bug in this fly tying video tutorial.

The Origin of Frank Sawyer’s Killer Bug

Frank Sawyer originally developed the Killer Bug (in the 1930’s) to eradicate grayling from the river Avon where he worked as the river keeper. Reportedly, the Killer Bug, which was tied to imitate a scud, was more effective than even netting or electro-fishing – hence the name Killer Bug. Now that’s a ringing endorsement if I ever heard one!

Killer Bug Material List

Hook: Kamasan B170, size 12
Thread: Fine Copper Wire
Body: Chadwick’s 477 Wool Yarn

Ok, so that’s a pretty simple material list, right? The catch is that Chadwick’s 477 hasn’t been manufactured in over 40 years and is damn near impossible to find, save the occasional card that shows up on eBay now and again and usually goes for over a $100 bucks. Ouch!

Veniard’s does sell a Killer Bug Yarn substitute, but some say it lacks the color changing property that Frank Sawyer claimed made Chadwick’s 477 so effective. See, the original Chadwick’s 477 completely changed colour when wet from a greyish brown to a pinkish tan due to red fibers present in the wool, which presumably better matched the scuds he was imitating. All is not lost though, there are other options.

In particular some folks have reported good success with Jamieson’s Shetland Spindrift Yarn in either Sand or Oyster which does contain those magical red fibers and changes color when wet. Jamieson’s Shetland Spindrift is available in many stores that carry knitting supplies and online.

Killer Bug – Scud or Crane Fly Larva Imitation?

While the Killer Bug was intended to imitate a scud it bears a striking resemblance to a crane fly larva or visa-versa I suppose. Given the ubiquitous distribution of crane flies throughout the world and that they are a favored food source of trout, particularly in the winter, I wonder if the Killer Bug is actually a better crane fly larva imitation than it is a scud imitation. Either way, the Killer Bug works!

Enjoy!

About the Author Ken Sperry

Ken is an avid fisherman of 40+ years who loves to explore and is on a quest to map the best places for fly fishing in America. He created DIY Fly Fishing and the DIY Fly Fishing App to share this information and help you find new places to fish. Have a question? You can get in touch with Ken here.

Leave a Comment:

Cheyenne1111000 says

Hello Davie,
I love your videos!! About the discussion of the wool you use I can say that the grayling love my version tied with bisam. This is my best grayling-killer……with a small spot of copper-wire at the end…. Please go on with your excellent work of fly-tying……All the best Thomas

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skipperfox007 says

Hi Davie, what a simple fly but if the wool is as rare as you say this fly will become extinct, which is a shame. regards Alan

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testflyfisherman says

a very well tyied fly i must say,i thing its one of my fave grayling paterns.lathkill do a great chadys 477 sub.

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daygum10 says

@bjk0uw0

A sub for Chadwicks is N 477 veniards Killer Bug Yarn

ATB

Gary

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daygum10 says

@bjk0uw0

A sub for Chadwicks is N 477 veniards Killer Bug Yarn

Reply
daygum10 says

a subsitute for chadwicks is No 477 killer bug yarn

ATB

Gary

Reply
daygum10 says

a subsitute for chadwicks is No 477 killer bug yarn

Reply
JohnBuckley14 says

Hello Davie
i think if my mother knew how much a small amount of it is worth she wouldnt mind in the slightest. .
All the best and tight lines
John

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DavieMcPhail says

Hi JohnBuckley14,

Don’t tell your mother that you are using you school jumper to tye flies but if it catches fish like the real material then you could sell your jumpers for a great profit…

All the best Davie

Reply