Chironomid (Bomber)
The Chironomid Bomber is a highly effective stillwater pattern that imitates midge pupae—arguably the most important food source for trout in lakes, reservoirs, and slow-moving river sections. Chironomids (non-biting midges) are present in tremendous numbers in most stillwaters, and trout feed on them throughout the year, making accurate imitations essential for consistent success. While midges are also important in rivers, the Bomber style was specifically developed for lake fishing techniques. The 'Bomber' name comes from the pattern's distinctive appearance with prominent wing buds or wing pads that suggest a pupa ready to emerge. The pupal stage is when chironomids are most vulnerable and available to feeding trout, as they must suspend in the water column and eventually break through the surface film to complete their transformation into adults. Trout key on these helpless, protein-rich morsels with laser-like focus, often feeding exclusively on chironomids to the exclusion of all other food. What makes the Chironomid Bomber deadly is its realistic profile and the ability to fish it at precise depths using a strike indicator. The pattern features a slender, segmented body with prominent white or cream-colored gills or breathing filaments near the head, and wing buds that catch light and suggest life. When suspended motionless at the depth where trout are feeding—often revealed by electronic fish finders or observed rises—the pattern is incredibly effective. This pattern excels in Western stillwaters from British Columbia to California, particularly in lakes with clear water and abundant chironomid populations. Fishing techniques involve suspending the fly at a specific depth beneath an indicator and allowing it to hang motionless or with minimal movement. Patience is essential—strikes can be subtle, and the angler must resist the urge to move the fly. The Bomber works year-round but is especially productive during spring and fall when chironomid emergences are most prolific.
Pattern Details
- Type
- Nymph
- Seasons
- spring, summer, fall
- Hook Sizes
- #12-18
- Hook Type
- Curved scud/pupa hook
- Tying Difficulty
- Intermediate
- Imitates
- Midge pupae (chironomids)
Recipe & Materials
- Hook
- Tiemco 2487 or similar curved hook, sizes 12-18
- Thread
- 8/0 black, olive, or red to match body
- Body
- Thread wraps, wire, or vinyl rib for segmentation
- Rib
- Fine wire or tinsel for segmentation
- Gills
- White or cream antron, poly yarn, or CDC
- Thorax
- Black, brown, or olive dubbing
- Wing Buds
- White or pearl mylar, Flashabou, or thin skin
Technique & Presentation
Chironomid Bomber patterns require attention to proportion and profile to accurately mimic the slender natural pupae. Start with a curved hook that provides the characteristic bent appearance of midge pupae. Build a smooth thread base along the entire shank. For the body, many tyers simply wrap thread in tight, touching turns to create a segmented appearance, while others use vinyl rib, wire, or tinsel for more pronounced segmentation.
Body colors should match local chironomid species—black, olive, brown, and red are most common, though orange, green, and purple can also be effective. Keep the body very slender, resisting the urge to build bulk. About one-third of the way back from the eye, tie in a small amount of white antron or poly yarn fibers extending from the sides to represent gills or breathing filaments—these are a key trigger for feeding trout.
For the thorax, apply a slightly bulkier ball of dubbing in dark colors (black or brown typically). Over the top of the thorax, tie in a small strip of white or pearl mylar, Flashabou, or thin skin to create prominent wing buds that extend slightly over the body. These should be bright and visible, catching light in the water. Build a small thread head, whip finish, and apply head cement. Some tyers add a small glass or metal bead at the head for weight and an additional attractor element. The finished fly should be slender with distinct white or light-colored elements at the head area.
History & Origin
Chironomid fishing in stillwaters has a rich history in British Columbia, where innovative anglers developed specialized techniques and patterns for these tiny but abundant insects beginning in the mid-20th century. Canadian fly fishers like Brian Chan, Phil Rowley, and others pioneered chironomid imitations and the suspending indicator techniques that have since spread throughout Western North America.
The Bomber style of chironomid pupa emerged as tyers sought to create patterns with prominent wing buds and gills that matched the appearance of pupae suspended in the water column. The name likely derives from the pattern's early versions that featured exaggerated white wing cases suggesting a bomber aircraft viewed from above. As understanding of chironomid biology improved through the 1980s and 1990s, patterns became more refined while retaining the essential elements that make them effective.
Phil Rowley's extensive research and writing on chironomid patterns and fishing techniques, documented in books like "Fly Patterns for Stillwaters," helped popularize these patterns beyond British Columbia. The Bomber and similar chironomid pupa patterns are now standard offerings in fly shops throughout the West, available in a rainbow of colors to match the diverse species found in different lakes. Modern materials like holographic tinsel, UV-reactive dubbing, and precision thread work have further refined these patterns, but the fundamental design—slender segmented body with prominent gills and wing buds—remains unchanged from the innovations of pioneering stillwater anglers.
Where to Fish This Fly
Related Nymph Patterns
Pheasant Tail Nymph
Frank Sawyer's classic nymph pattern imitates a wide range of mayfly nymphs. The pheasant tail fibers create a realistic segmented body. Effective year-round in sizes #14-20, this pattern belongs in every Montana fly box. The Pheasant Tail Nymph is the most important subsurface fly in the history of fly fishing. Frank Sawyer's original design used nothing but pheasant tail fibers and copper wire, with no thread, no dubbing, no synthetics. The result was a slim, naturally segmented nymph that sinks quickly and perfectly imitates the profile of a swimming or drifting mayfly nymph. Modern variations have added a bead head for extra weight and flash, making an already deadly pattern even more effective. In Montana, the bead head Pheasant Tail is a year-round producer on every river in the state. It matches Baetis nymphs in fall and spring, PMD nymphs in summer, and various mayfly species throughout the seasons. Whether fished as a trailing nymph behind a dry fly, in a two-nymph Euro-style rig, or under an indicator, the Pheasant Tail consistently catches fish. Its slim profile sinks quickly and looks natural even to the most selective trout on the Missouri and Bighorn tailwaters.
Zebra Midge
A devastatingly simple midge pupa pattern. Thread body with a bead head, and that's it. The Zebra Midge is the most effective winter pattern on Montana tailwaters and produces year-round on the Missouri and Bighorn rivers. The genius of the Zebra Midge lies in its simplicity. A small bead head, a thread body wrapped in even turns to create segmentation, and perhaps a few fibers for a collar, and that is all there is to it. Yet this pattern imitates the midge pupae that comprise an enormous percentage of a trout's diet on tailwater rivers. Midges hatch every day of the year on rivers like the Missouri and Bighorn, and the Zebra Midge matches them with astonishing effectiveness. The pattern's versatility is remarkable. Fished under an indicator in the classic dead-drift presentation, it produces fish consistently. But the Zebra Midge is also deadly when fished in the surface film as a midge cluster or suspended just below the surface on a greased leader. On winter days when other patterns fail, a small Zebra Midge in #18-22 fished deep and slow can save what might otherwise be a fishless outing. It is the great equalizer, the fly that always works when nothing else does.
Prince Nymph
A classic attractor nymph with peacock herl body and white biots. The Prince Nymph doesn't imitate any specific insect but suggests many. It's a reliable searching pattern when drifted through riffles and runs on all Montana rivers. The Prince Nymph occupies a unique space in fly fishing; it is perhaps the most effective attractor nymph ever designed. The combination of a peacock herl body, white goose biot wing, and brown hackle creates a fly that doesn't precisely match any natural insect but somehow suggests dozens of them. Trout see the Prince Nymph and recognize it as food, plain and simple. The iridescent sheen of the peacock herl, the contrasting white wings, and the buggy profile all contribute to its universal appeal. In Montana, the Prince Nymph is a workhorse pattern that produces fish from the first runoff of spring through the cold days of late fall. It excels as a dropper behind large dry flies, as a searching nymph under an indicator, and as a point fly in a two-nymph rig. On the Madison, Gallatin, and Yellowstone rivers, the Prince Nymph consistently produces when conditions are changing, hatches are unclear, or fish seem unwilling to commit to specific imitations. It is the problem-solving nymph that every angler should carry.
Pat's Rubber Legs
A large, heavily weighted stonefly nymph pattern. Pat's Rubber Legs is the go-to point fly for nymph rigs on the Madison, Yellowstone, and Gallatin rivers. The rubber legs pulse with every micro-current, driving trout wild. Pat's Rubber Legs is the definition of a workhorse nymph. This large, heavily weighted stonefly imitation serves as both an effective fish catcher and the anchor fly in a multi-nymph rig. Its weight gets the entire rig down to the bottom quickly, while its rubber legs provide continuous movement that attracts trout from a distance. The variegated chenille body suggests the mottled coloring of natural stonefly nymphs, and the overall profile matches the large Pteronarcys and Hesperoperla nymphs that inhabit Montana's freestone rivers. On the Madison, Yellowstone, and Gallatin rivers, all premier stonefly streams, Pat's Rubber Legs is arguably the most important fly in a guide's box. It produces fish 12 months of the year, not just during the stonefly emergence. Stonefly nymphs are always present in the drift, dislodged by current, wading anglers, and their own movements. A large Pat's Rubber Legs drifted along the bottom is a convincing imitation that trout eat with confidence. Pair it with a smaller trailing nymph like a Pheasant Tail or Lightning Bug for a devastating two-fly rig.
San Juan Worm
Love it or hate it, the San Juan Worm catches fish. This simple chenille or micro-tubing pattern imitates aquatic worms that are a significant food source in tailwater rivers. Particularly effective on the Bighorn and Missouri after rain events. The San Juan Worm divides the fly fishing community like no other pattern. Purists dismiss it as barely qualifying as a fly, while pragmatists point to its undeniable effectiveness and the scientific reality that aquatic worms (Oligochaeta) constitute a meaningful portion of trout diets, particularly in tailwater environments. On the Bighorn River, stomach sampling studies have shown that aquatic worms can represent up to 20 percent of a trout's diet during certain times of year. Regardless of where you fall in the debate, the San Juan Worm deserves a place in your fly box if you fish Montana's tailwaters. After rain events, rising water dislodges worms from the substrate and puts them into the drift, creating a feeding opportunity that trout exploit enthusiastically. Even during stable conditions, a San Juan Worm fished deep and slow on the Bighorn or Missouri can produce fish when more traditional patterns are not producing. The pattern is especially effective for large trout that have learned to target high-calorie food items with minimal effort.
Lightning Bug
A flashy variation of the Pheasant Tail that uses tinsel and flash for added attraction. The Lightning Bug excels in slightly off-color water and as a dropper behind large dry flies. A Montana guide favorite. The Lightning Bug takes the Pheasant Tail Nymph concept, a slim, segmented mayfly imitation, and adds a generous dose of flash. The tinsel body and flashback wingcase catch light in ways that natural materials cannot, creating a beacon that attracts trout from greater distances. This makes the Lightning Bug particularly effective in off-color water, during overcast conditions, and in deeper runs where light penetration is limited. Montana guides keep Lightning Bugs in their boxes for those days when standard patterns are producing but not as well as expected. A switch from a standard Pheasant Tail to a Lightning Bug can turn an average day into a great one. The flash element seems to trigger a competitive or aggressive response in trout, prompting strikes from fish that might otherwise let a natural-colored nymph pass. On the Madison, Gallatin, and Yellowstone rivers, the Lightning Bug is a consistent producer from spring through fall.