The Red Butt House Fly is a floating pattern that can imitate a wide range of terrestrial insects. The pattern is a spinoff of a trout fly I tied to imitate the common green bottle fly. The original pattern for trout fishing lacked the crystal flash tail and was tied smaller on a size 14 hook. It was a good late-season searching pattern when trout were accustomed to feeding on various terrestrial insects. The fly also served as a good imitation of the deer fly, a biting pest found in damp, wooded, or wetland environments such as marshes, ponds, and streams in many locations. On some waters I can add a hundred bodies of this scourge of an insect to the water in a day's fishing as I continually swat at them as they try to bite me! I'm sure some of those dead flies end up in a fish's stomach.
This is the original, smaller version without the crystal flash tail, that was primarily used for trout, although I doubt a panfish would turn its nose up to it.
The Panfish Version
The panfish version was tied on a larger size 12 hook (smaller and larger versions will also work) and included the addition of a short crystal flash tail for a little extra bling and movement when fished on still waters. Panfish show a distinct preference for the larger, dressed-up version. These insects often have distinctly colored red or burgundy eyes, so I added them. The red foam eyes on the fly may be overkill, so feel free to omit them. Color and contrast can make a difference in certain conditions. I can't say it makes this fly any more productive, but I go the extra yard by tying it with red thread and adding the red foam eyes. If you believe hot spots trigger a fish to take a fly, experiment with any color you like, or go with black thread and omit the eyes to create a strong silhouette.
One of the many trout caught on a chilly fall day on a modified Red Butt House Fly.
The Fly That Saved The Day
This fly once saved what would have been a fruitless day on the water on one of my trout-guiding trips a few years back. It was a very chilly fall morning, and the fishing was off. A few fish were rising to the odd midge, but I like to keep things simple on guide trips, and size 24 flies on 7x tippet seemed like a bit much for the beginner angler I was working with. However, the nymphs and streamers I fish on these waters were not producing as usual.
The occasional rise of a fish had my client itching to catch a fish. So I had him reel in and took the rod from him to re-rig with a fine leader and small midge pattern. As I was doing this, I noticed bits of what appeared to be hay or straw floating downstream. Whenever some straw passed downstream, the fish began to feed on the surface in earnest, and then it would subside until more straw floated by. I studied the water's surface to identify what the fish were feeding on. When another batch of straw floated by, I observed a dark speck on the water. Following the speck downstream, I watched a nice trout rise confidently and eat it.
I caught the next speck floating downstream and was surprised to find a dead common house fly in my hand. I reached for my sling bag to grab my terrestrial box, only to remember that I had removed it and replaced it with another midge box a few weeks earlier after the first killing frost.
I dug through several fly boxes for an appropriate imitation but came up empty. While putting away my last box, I noticed a mangled green fly stuck in the drying patch on my sling bag among the dozens of other flies residing there. I plucked it from the drying patch and figured, "What the hell, it's worth a try."
The fly was the Red Butt House Fly. I don't recall how or when this fly found its way onto my trout bag, but there it was. I quickly opened my Leatherman tool and used the scissors to snip away the crystal flash tail. The fly was larger than the bugs the fish were feeding on, but it was our only option.
I cut back that long 7x leader to a shorter one that probably terminated at around 5x. I then tied on the fly and returned the rod to my client. A fish rose to the fly on his first cast, but he set too soon and missed the fish. After a brief coaching session, he was at it again, and a few casts later, another fish rose to the fly. He set the hook perfectly this time and landed a nice rainbow trout. We fished that fly all morning, getting interest from almost every fish it passed. Many rejected the pattern due to its larger size, but there were enough less discriminating fish to save the day. The fishing abruptly stopped when a big trout grabbed the fly and was lost during the fight, taking the fly with him.
What took place that day is still a mystery. Just upstream of where we were fishing was a horse farm. The evidence of the bits of straw in the water indicated that there was some stall cleaning going on, and maybe the wind was carrying some of the debris to the water, and along with the straw were the flies either killed or stunned by the cold. There did not appear to be enough straw to indicate that somebody was deliberately dumping it in the river, so I could not say what was happening upstream.
Notes On Tying the Red Butt House Fly
I have a general rule that every fly pattern allows for substitutions of materials. Maybe you don't have a particular material on hand, or you have an idea to improve the pattern for your fishing needs. Always feel free to do so. Working in a fly shop, I encounter many tiers unwilling to swap out material just because a fly pattern calls for obscure or hard-to-find material. In the case of this pattern, for example, maybe an orange or yellow butt house fly is more to your liking. I added the crystal flash tail to add movement and contrast to the pattern, so if you have a color that you feel is more productive on your waters, go for it. The same goes for foam. If you don't have iridescent green-backed foam, use black, as the fish don't see the top of the fly. That material was chosen more for the fisherman than the fish.
If you don’t have Loco foam or synthetic peacock here on hand feel free to substitute standard craft foam and the underbody material of your choosing.
The original trout version had an underbody of peacock herl, a delicate material. When I tie flies for panfish, I try to make them as robust as possible so they can withstand dozens of fish before wearing out. That is why I opted for a more durable synthetic herl or other synthetic body material. A list of some alternatives can be found in the pattern recipe below.
Since the pattern serves double duty as a general terrestrial insect imitation, you can change the foam color to whatever suits your needs. Tie the pattern in natural hues or bright attractor colors; I have found them all effective.
The Antron wing is a visual reference for the angler to keep track of the fly on the water's surface. While I use a cream-colored wing, feel free to make substitutions here. A hi-viz wing of yellow or orange can make the fly more visible in low-light conditions, and a wing of solid black gives the fly a good silhouette in high-glare situations.
The point here is to feel free to experiment and have fun behind the vise!
Pattern Recipe:
Hook: Standard Dry Fly size 12 ( feel free to tie the fly larger or smaller)
Thread: Red 6/0 Semperfli Classic Waxed
Tail: Red Crystal Flash trimmed to the width of the hook gap (omit on trout version)
Body: Peacock Green Loco Foam
Underbody: Semperfli Synthetic peacock herl, Semperfli Micro Fritz or Semperfli Straggle legs
Wing: Cream or other colored Antron trimmed to a length that reaches half of the tail
Eyes: Red Chicone's Fettuccine Foam
Hackle: Appropriately sized Grizzly dry fly hackle trimmed flush with the bottom