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How to Tie the Killer Bug

Utah Killer Bug

I discovered this archaic pattern in the book Simple Flies by Morgan Lyle.  The story goes that Frank Sawyer, the same guy that developed the venerable Pheasant Tail Nymph, created this fly, too.  Mr. Sawyer was the caretaker, or River Keeper as they are known in the United Kingdom, of the River Avon. One of his responsibilities was to eradicate the undesirable grayling from the watershed. He tied up the killer bug using readily available yarn, not coincidentally but aptly named for the job at hand, and proceeded to catch and kill every grayling in that stream. That was the end of those pesky grayling, foiled by Mr. Sawyer and his meddling Killer Bug!  Or, so I have read.

Unlike Mr. Sawyer, I’m not much into killing grayling in exponential numbers, but I am into catching trout. And catching trout is what this fly does. Like Walt’s Worm, this fly simply looks grubby.

The original Killer Bug was tied with a specific yarn call Chadwick’s 477, which is now an incredibly hard material to find, and when you do find it, it sells for exorbitant prices. In recent years, Chris Stewart of Tenkara fame, has renovated this pattern using Jamieson’s Shetland Spindrift Wool Yarn, which contains many of the same features as the original material. The oyster-colored yarn has a translucent and pink sheen to it when saturated. It looks meaty and apparently delicious to trout because they readily eat this thing.  

The Killer Bug is a pattern that often saves the day for me. Unlike Walt’s Worm, I rarely start a new fishing session with a killer bug. Instead, I reach into my fly box for one when I am having a tough day, when the fish are not cooperating and kicking my butt! More often than not, this fly change results in a few fish in the net to shake the skunk. Maybe I should learn from this fact and start a new session with a Killer Bug. This might result in more trout in my net more often.   

And just when you thought tying up a Walt’s Worm is the easiest pattern in the books, in comes the Killer Bug. Thread your bead onto the hook and create a thread base. Add some wraps of lead wire if this is your preference. Tie in a length of oyster wool yarn just beyond the bend, wrap up to the bead, trap, trim and whip finish.  That is all it takes to tie this nymph. One tip of note is when I’m wrapping the yarn, I roll it in my fingers to tighten the twist. This provides a slightly segmented look indicative of a grub, larvae or worm.   

Fly Recipe

  • Jig nymph hook of preference in #12-16
  • Tan or Cream 8/0 thread
  • Tungsten slotted bead in silver, copper or black
  • Body: Oyster Jamieson’s Shetland Spindrift Wool Yarn
Utah Killer Bug
To tie this simple, effective pattern, tie in a length of Jamieson's Shetland Spindrift yarn in Oyster color as pictured.
Once the yarn is tied in, use touching wraps to advance it to the bead. Secure with a whip finish and that's it! A great pattern that catches trout everywhere.

Watch the Tying Tutorial for the Utah Killer Bug and an Easy Variation

Did You Find This Fly Tying Guide To be Helpful?

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