FOR MANY ANGLERS, the mere mention of midge fishing strikes terror into their hearts. The thought of nearly invisible flies, ultra-thin tippets, and selective trout conjures up images of frustrating fishing and few fish brought to hand. But for the visitor to the spring creeks and stillwaters in the Paradise Valley of Montana, midge fishing may produce some of the best angling the area has to offer, and learning more about midge fishing will take some of the mystery and challenge out of fishing these tiny flies.
What is a midge? Although some anglers refer to any small fly—natural or artificial—as a midge, the term is more accurately used to refer to several families of insects in the order Diptera, the two-winged flies. For anglers, the midges that make up the most important portion of a trout’s diet are the chironomids, members of the family Chironomidae. (Some other midges like blackflies, dixid midges, and phantom midges can be locally important.) As the name implies, most midges are quite small, best imitated with hook sizes 18 and smaller.
Because of their small size, midges must be present in large numbers to make them a viable food source for the fish. This is usually not an issue because chironomid midges are found in any cold water environment that will support trout, and they often occur in mind-boggling numbers—tens of thousands of midge larvae may be found in a single square meter of silt in the bottom of a pond. Scientists tell us that the dipteran insects usually make up at least half of the species of aquatic insects in any freshwater ecosystem.
Another reason for their importance as trout food is due to the fact that midges may hatch at any season of the year. Depending on water temperatures, midges are often multibrooded; that is, a single species may reproduce several times in a single season. On the Paradise Valley spring creeks, midges are found hatching all year long, even on calm days throughout the winter, but the best hatches will be from late February through October.
But even though their abundance makes up for their small size, midges are most important as a trout food in slow moving streams (like spring creeks and tailwaters) and in lakes and ponds because trout can feed more efficiently on small food forms in these conditions. Midges are often found in good numbers in faster streams and rivers, but in these conditions, the fish would expend more energy capturing these tiny insects than they could gain by eating them.
However, even in fast freestone streams, midges can be locally important in the tailouts of large pools or in backeddy currents. Midge hatches provide good early spring fishing on a number of larger rivers in my area, including the Yellowstone and lower Madison. Midges become less important later in the season on these streams, as hatches of larger insects begin.
The Midge Life Cycle and Trout Feeding Behavior
As with other insects, learning something about the life cycle of midges can provide useful information to the angler. Knowing about the appearance, habitat and behavior of midges allows us to design better imitations and fish them in a more realistic fashion.
While some anglers may try to identify mayflies, caddisflies, and stoneflies very specifically (even keying them to a species level), this is not practical with midges, since there are several thousand species known in North America alone. As long as the angler is familiar with the general appearance and behavior of midges, further identification can be limited to noting the size and color of the insect.
Midges go through “complete metamorphosis” as they grow and develop, with distinct larval and pupal stages between the egg and adult stage. The larval stage of a midge is a very simple wormlike form, very slender with noticeable segmentation in the body. The head and thorax are not well developed, so they blend in with the overall shape of the body. Midge larvae can adapt to a wide variety of habitats, but they are most common in aquatic vegetation and silt bottoms. Midge larvae can be almost any color, but olive, tan, cream, and black are some of the most common. Larvae that burrow into silt or mud with little oxygen are often bright red and are called “bloodworms”. Although midge larvae spend most of their lives in the weeds or on the bottom or a stream or pond, they are capable of some movement by wiggling their body back and forth.
Pupation is the process in which the simple larva is transformed into the adult insect. Like caddisflies, some midge larvae (blackflies, for example) seal themselves in a cocoon for pupation, but the chironomids have free living pupae that continue to move about during pupation. As the pupa develops, the thorax become larger and better defined, with obvious wing pads and gills. In lakes and ponds, midge pupae often rise to the surface at dusk and hang vertically just under the surface film, returning to deeper water at dawn. When these midge pupae congregate at the surface, they provide an easy meal for a cruising trout.
When the midge is ready to emerge (now properly called a pharate adult, as the insect is fully mature but still inside the pupal membrane), it generates gases inside the pupal shuck, which buoys it to the surface. Once the insect reaches the surface film, it breaks free of the pupal shuck, and climbs out onto the surface. Fish prey heavily on the midges as they are struggling to free themselves from the shuck, and this is by far the most important stage to the angler. In most cases, however, the adult midge is able to fly away relatively quickly after emergence, making adult patterns much less important than surface emergers to the angler.
On some tailwater streams (like the Bighorn here in Montana or the San Juan in New Mexico), midges will form mating clusters, with a group of males surrounding a single female insect. These clusters of insects provide a substantial amount of food to a feeding fish, and where trout become selective to these clusters, large high riding dry flies can be very effective.
Midge Fly Designs
The life cycle described above suggests a range of artificial patterns that can be used to imitate midges, and I will discuss the features that I think are critical to effective fly patterns.
One of the key features of an effective midge larva pattern is its slim profile. It is almost impossible to make a midge larva pattern too slender. Many fly tiers have discovered that the simplest patterns will work as a midge larva imitation—nothing more than a layer of thread on the hook shank or a thin layer of dubbing can work very well. Some anglers use a bare hook with no dressing at all with success, especially a hook with a black or bright red finish.
The other key feature of a midge larva imitation is its segmented appearance. There are a number of materials that mimic this segmentation. A contrasting wire or thread rib can make a thread or dubbing body appear segmented, as on the Miracle Nymph. Wrapped wire—as on a Brassie or Copper Nymph—is another traditional material that mimics segmentation and also provides weight without extra bulk. Fly tiers were once limited to copper and gold wire for this type of fly, but a variety of colors are now available, including red, green, olive, and black. Stripped quill and turkey biot are other materials that give the appearance of segmentation.
Midge pupa patterns can be very similar to larva patterns, but the thorax should be emphasized. Fur dubbing, peacock herl, and ostrich herl can all be used to build up enough bulk and color to mimic the thicker thorax of a midge pupa.
Patterns designed to represent the emerging midge as it makes it way to the surface should mimic the sparkle of the gas bubble inside the pupal shuck. Modern patterns (like the Disco Midge and the Krystal Flash Midge Larva) use Mylar materials like Flashabou or Krystal Flash, but older materials like a wire or tinsel rib may perform the same function.
Pupa patterns that are designed to be fished vertically just under the surface usually incorporate some floating material to keep the head of the fly at the surface. John Goddard’s Suspender pattern was one of the first to use foam for this purpose, and a number of similar patterns use foam, parachute style hackle, clipped deer hair, or CDC for floatation. In my own experience, I find these patterns to be much more useful in lake fishing than in stream fishing, as I think the pupae hang at the surface much longer in stillwaters. For stream fishing, I find surface emergers to be much more effective.
Midge larvae and pupae are capable of motion, but in most cases, their undulating movements are impossible to mimic with line handling techniques. However, tying these patterns on a curved (or slightly bent) hook may give the appearance of motion, and curved hook patterns are both effective and popular. These curved hook styles do not hook the fish as effectively in very small sizes, and it may be helpful to offset the hook point slightly on the smallest sizes.
Surface Emerger Patterns
Surface emergers are designed to imitate the adult midge just as it pulls free of the pupal shuck. Although it might sound obvious, the most important part of a surface emerger’s design is the correct amount of flotation to hold it in the surface film. As with the “vertical pupa” patterns described above, various materials can be used (foam, CDC feathers, hackle, etc.).
It is important for anglers and fly tiers to note that very small variations in tying technique can affect how the fly floats and how it appears to the fish. For example, René Harrop uses CDC in several of his midge emerger patterns, but gets a very different effect by varying amounts of this material and applying it in different ways. His CDC Midge Emerger uses a tiny tuft of CDC for flotation. This fly sits very low, and although it can be difficult to see and requires some attention to keep it floating in the film, this pattern is one of the deadliest in my boxes. The Harrop Biot Midge Emerger has a folded wing pad plus sparse outriggers of CDC, allowing it to float a bit higher. The Harrop Transitional Midge combines an ingenious looped wing of CDC with a grizzly hackle tip shuck. These patterns are similar, but each presents a slightly different view of an emerging midge to the fish.
Over the years, I have experimented with a variety of surface emerger patterns, and I have always been frustrated by the fact that many patterns are inconsistent in their effectiveness. A new design may catch fish like crazy for a trip or two, but then is totally ignored by the trout the next time out. (Trying to design an effective midge emerger reminds me of author Mark Twain’s joke about quitting smoking—he said it is the easiest thing in the world to do, as he had done it a thousand times. Likewise, I know I have invented the world’s best midge emerger—at least a dozen times by now.)
I am now convinced that at least part of the reason an emerger pattern can be effective one day and useless the next is that the fish can become very selective to the precise moment at which they take these surface emergers. If the fly rides too high or too low, it is ignored. The best way to deal with this problem is to carry a variety of emerger styles, some with more flotation and some with less, and be prepared to switch patterns after several refusals.
The other key element of a surface emerger is to imitate the pupal shuck itself. As the hatching midge pulls free of the pupal shuck, the whole insect appears to elongate, and there is a slight hesitation just before the midge and shuck separate. This is the stage that the fish prey on most heavily, and imitating the trailing shuck is critical. Various materials can be used, but my favorites are a small grizzly hackle tip (as on the Harrop Transitional Midge) or olive/brown sparkle yarn or Zelon.
Although adult midges are much less important (to both fish and anglers) than surface emergers, they can be effective at times. Patterns to imitate an individual adult midge are similar in appearance to a surface emerger, except that the trailing shuck is left off, and it should be tied to ride higher on the surface film. When the fish key in on clusters of mating midges, an oversized Griffith’s Gnat (as large as a #14 or 16) is an excellent pattern to imitate these groups of bugs.
I will detail some techniques for fishing specific midge patterns below, but it might be helpful to note some general ideas here.
One of the skills that will make any angler more successful is the ability to read riseforms. Especially on spring creeks and tailwaters, the ability to determine what the fish are feeding on (without wading into their midst) is a tremendous help in selecting the right fly and presenting it properly. Recognizing the riseforms associated with emerging midges is a first step in fishing the patterns successfully.
In most cases, midge fishing involves heavy hatches of very small insects, so the fish are usually rising very steadily in order to capture enough food to make a meal. This kind of feeding behavior is both good news and bad news for the angler. The bad news is that the angler’s artificial is competing with hundreds or thousands of natural insects for the fish’s attention. The good news is that the fish is rising often, giving the angler more opportunities for the fish to take the fly during the hatch.
Also, since the fish is really concentrated on feeding, the angler can usually get close to the fish (with a careful approach), and this is the best way to deal with this kind of feeding behavior. Get close, and make as many, short, accurate casts as possible. Long casts waste time and are more difficult to control, and they are rarely needed in this type of fishing.
Since there are so many species of midges, we are lucky that the behavior of the whole family of chironomids is similar. This means that the same styles of patterns will work for most midges—all we have to do is match color and size.
I find that matching color precisely is rarely important with midges, but experience has taught the guides on the Livingston spring creeks that fishing larva and pupa patterns in a variety of colors is important. Just as fish respond to a steady supply of the same food items by feeding selectively, they respond to seeing the same artificials (especially if they are hooked on them repeatedly) by refusing them. I call this response to heavy fishing pressure “pattern fatigue,” as opposed to selectivity, a natural response to a profuse supply of a limited range of food items. Even the best fly design will become less effective over time, if every angler on a heavily fished stream uses it. Carrying a variety of fly colors or styles may be more important than having one perfect imitation.
Matching the size of the natural midges is very important. As Swisher and Richards explain in Selective Trout, proportional differences in size are much greater in smaller flies; that is, there is a larger proportional difference in size between a size 20 and a 22 than there is between a size 10 and 12. In my experience, the fish will rarely refuse the fly because it is too small, but they usually refuse a fly that is too large. One helpful on-stream rule that follows from this is that if you are unsure about size, pick the smaller pattern.
In writing this article, I reviewed most of the literature on midge fishing, and I was surprised to read so many knowledgeable authors state that fishing larva patterns is of little importance, since this is one of the stand-by techniques on the Livingston spring creeks.
It is true that midges—like most aquatic insects—are most vulnerable when they emerge, and the ascending pupa, hanging pupa, and the surface emerger are the most important stages to both fish and anglers. However, midge larvae are numerous enough to be a significant part of the drift of food in most spring creeks and tailwaters. I find that dead drifting a midge larva pattern is an excellent searching technique when there is no hatch, similar to fishing imitations of other common foods like small mayfly nymphs, scuds, or small terrestrials like ants and beetles.
Also, since chironomid pupae are mobile during pupation, the behavior and appearance of larvae and pupae are similar until emergence actually begins. For this reason, the dead drift techniques for both larva and pupa patterns are the same.
The most common technique for fishing larva and pupa patterns is under a small strike indicator. On the slow moving currents of spring creeks, I prefer the smallest indicator that still provides visibility and flotation. Yarn and roll-on foam are the most popular indicators on the Livingston spring creeks. Fishing the larva or pupa under a small dry fly or even a CDC midge emerger pattern also works well. Although a fly is usually less visible and buoyant than yarn or foam, it also spooks fewer fish and the fish may actually take (and get caught) on this kind of indicator. Although I don’t recommend fluorocarbon tippet material in all situations, it works well with these subsurface midge patterns because it sinks through the surface film without needing split shot or other additional weight on the leader. An indicator is also the best method for fishing a suspended pupa pattern in stillwaters—fishing a large (#14) pupa pattern several feet under the surface is a standard technique on Burns Lake, Buckingham Lake, and other stillwaters in our area.
In the greased leader technique, the angler dresses the leader with a paste fly floatant (thick silicone pastes work best), down to within a few inches of the fly. This controls the depth of the fly’s drift, and the angler watches the point where the tippet passes through the surface film for indications of a strike. While this removes the bulk of an indicator from the leader—allowing better accuracy and a more subtle presentation of the fly—it also offers much less buoyancy and is much harder to see. This approach works best on very slow currents, and on lakes and ponds when there is minimal wind, as the greased leader will sink in faster or choppy water. It also works well when the light is low, as the greased leader shows up in flat light as a dark line on the surface film of the water. The greased leader technique is perhaps the best method for suspending a pupa pattern just under the surface. In stillwater situations, where the numbers of suspended pupae may be astronomical, a very slow draw of the fly may make it more visible to the fish, and make it easier for the angler to detect a subtle strike.
In the right conditions, one of the most effective techniques is to remove the indicator entirely and detect strikes by watching the fish react to the fly. Like the greased leader technique, the absence of any bulk on the leader allows for more accurate casting and creates less commotion when the fly is presented.
There are several critical ingredients in this technique. One is that the fish must be visible, so good spotting light is essential. The angler must also be able to mark the fly as it hits the water to make sure the fly is presented in the same current line as the fish. It is also important to be able to judge the sink rate of the fly, as the fly needs to be presented far enough upstream of the fish to get the fly to the fish’s level.
If these prerequisites are met, the angler makes the cast and then follows the fly’s progress at the speed of the current until it nears the fish. At that point, the angler’s eyes shift their focus to the fish and watch for a reaction. If the fly is in exactly the right feeding lane, the fish may just open and close its mouth. The interior of the fish’s mouth sometimes appears as a flash of lighter color, which is why some anglers refer to this technique as “white mouthing” the fish. Often, the fish will move slightly from side to side to intercept the fly, and the angler can judge from the fish’s body language when the fly has been taken. Look for the fish to make a sudden stop as it intercepts the fly, sucks it in, and turns back to its original lie. Quick reactions are essential—as soon as it detects that the fly is not food, the fish will try to eject the fly from its mouth. If the angler’s reaction time is slow, sharp hooks will also help—if you see the fish suddenly start to shake its head back and forth, it is probably trying to get rid of a sticky sharp hook. Sight fishing requires decent vision, the right light conditions, and a fair amount of practice. However, like most subtle angling techniques, it can be a deadly way to catch fish, and a whole lot of fun.
The greased leader approach and sight fishing are the best methods to imitate a midge pupa as it rises to the surface. The cast is made several feet above the fish, allowed to sink to the fish’s level, and then as the fly nears the fish, the angler stops the drift and uses a lift of the rod to move the fly toward the surface. If the fish are taking these ascending pupae, the upward movement will usually trigger a strike.
Fishing surface emerger patterns is similar to other dry fly fishing on slow currents. A variety of casting angles may work, but a reach cast quartering downstream is probably the best method for producing strikes. The angler should be prepared to miss a fair number of fish with reach cast presentations, as the hooking angle is poor. This situation is made even worse with the tiny hooks involved with midge fishing.
Clustering of midge adults is rare on the Livingston spring creeks, but I do find situations where the fish will feed on adult midges as they buzz along the surface of the water. In particular, I often observe fish on Nelson’s Spring Creek eating adult midges in very shallow water along the margins of the pond section. I have also seen concentrations of mating midges collected behind the logs in the upper flats at Nelson’s, apparently to escape the wind. Fish will sometimes key on these concentrations of bugs, rolling repeatedly in these confined areas, and eating several midges at a gulp. The fish seem to key on movement is these situations, so I fish a fly that floats well enough to be skated across the surface without drowning (like the Harrop CDC Midge Adult). A very slow draw of the line will make the adult skim across the surface in a lifelike manner.
Midge fishing may seem like one of fly fishing’s more challenging elements, but as long as an angler is willing to accept the difference in scale—fishing small flies on light tippets—it can also be one of the most productive and rewarding. In the Paradise Valley of Montana, midges are BIG.