March 2, 2013

Variations on a Bug

Like many of you, I have found the Killer Bug the be an indispensable fly, catching many, many fish. I have used it in all different types of water: slow, fast, deep, shallow. It seems to take fish, trout in my case, everywhere. I particularly like the Utah Killer Bug version.

I have been fishing with a few variations over this past year and I would like to share them with you. I'm sure that these are not new variations, but some I haven't seen before.

Utah Killer Bug
This is the classic UKB. I tie it on a barbless Euro competition hook unweighted. It is a mainstay of my fishing outings. Like all UKB variations, it uses Shetland Spindrift Oyster wool yarn. This wool looks pink when wet and because of the ragged fibers it has a beautiful "halo" making the fly appear somewhat transparent and alive.

Utah Killer Bug, weighted
This is exactly the same as the classic UKB but I use lead wire to add weight to the fly. So that I can tell the difference between the weighted and unweighted in my fly box I add a subtle wire tag. Again, this is more for me than the fish!

Red hook UKB
This is a UKB tied on a red Gamakatsu Octopus hook. I first fished this variation with ERiK Ostrander of Tenkara Guides LLC, the originators of the UKB. Brown trout seem to take it readily, especially on high gradient streams in winter.

Bug and Starling
This is just a UKB with starling tied as a soft hackle. This is similar to, but slightly different than, Chris Stewart's Killer Kebari. Also, you will note that I use black thread instead of the usual pink.

DC stands for "depth charge". This variation of the UKB works like dynamite in fast water or deep pockets. The sparse muskrat collar (tied with a dubbing loop) adds life to the fly, while the red "hot spot" aids in triggering the feeding or predatory instinct. Because the fly utilizes a tungsten bead (slotted, round or faceted) it is relatively heavy making it perfect for enticing the big fish at the bottom of plunge pools or deep runs. It is tied on a Euro jig-style competition hook. This allows the fly to ride "hook up" greatly reducing those annoying bottom snags.  This fly is heavy so cast it with a slow, "open" cast so not to hit your rod.

Here is a video of fishing with the DC UKB. You can see how well it works on moderate-to-high gradient freestone streams:

So, there are some of the variations of the UKB that work well for me. Do you have any other variations that work for you? If you do, I'd like to see them!


  1. I always get the impression of an caddis fly nymph when I see a soft-hackled killer bug. It would probably complete the impression if a wire wrap were put around the yarn body for better segmentation. Of course, if you changed the yarn to something greenish/chartreuse it would look even more like some caddis fly nymphs.

    What rod and line weight were you using in the video with the DC UKB? I got the impression the rod might have been the Suntech Field Master.

    1. I agree about the caddis-like appearance. I'm not sure what the trout take this fly for in my waters but I've suspected a crane fly larva.

      Yes, the Field Master was used in the video.


    2. Lynn,

      We've actually tried a number of green yarn colors, including various "apples" and "chartreuse". I even tried a chartreuse head with brown segmented body for a cased caddis imitation. To my surprise, none of them have really produced well.

      Here in Utah, working with DWR, or the rare occasion when we harvest fish, you frequently find fish bellies filled with cased caddis. However, our cased caddis are not as prone to drift as other species. I have since found references to brown trout scouring rocks and sticks like sucker fish to eat cased caddis. I wonder if this is the reason why the cased caddis seems to be more of a "red herring" in Utah.


  2. Wow, maybe the picture is spoiling my perception but to me the DC UKB looks awesome heavy.
    I'm used to cast bulky flies (#6 divers, popers) but i guess perhaps
    bulkier they are nos as heavy...
    What's that hook size?

    1. The image shows the fly as tied on a #10 hook, but it could be easily modified to a larger (or smaller) hook.


    2. Yep, i was spoiled, thought it was a much bigger hook. Guess #10 is very nice to cast n' fish with.

  3. Glad the UKB is working for you, Tom.

    The original was actually tied with red wire and black (iron grey) thread. I believe in adding a degree of contrast to flies, and still prefer tying it this way. I also like the deeper hue that the red wire imparts on the yarn. The UV pink is a variation that Erik likes.

    If you'd like, I can send you a few of our ER Wool Bodies (grave digger, red assed monkey, etc). The red assed monkey has actually replaced the UKB as my preferred fly.


    1. Thanks Rob. I'll have to try the UKB with the thread and wire rib variation.