Fly Tying 1 min read

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

Ken Sperry

Posted by Ken Sperry

February 5, 2011

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!