Hatch Profile – Arctopsyche grandis; My favorite Salmonfly pattern on the Madison River

Hatch Profile – Arctopsyche grandis; My favorite Salmonfly pattern on the Madison River

Fishing the iconic Salmonfly (Pteronarcys californica) hatch on the Fifty-Mile Riffle is an epic experience to say the least.  Snow-capped mountains and lush green hillsides frame a robust river flush with the bounty of early season snowmelt. Tremendous browns and rainbows rise eagerly to engulf massive insects from the surface. It’s the stuff of legends.

Though, like many phenomenons, they are all too often elusive. One day you’re a bit too far upstream of the hatch, the next day you’re too far behind it. Sometimes you’re right smack in the middle of the hatch, but the fish have seen too many bugs and reject your fly as if to say “sorry Sucker, better luck next time”.

Every so often, when the stars align, you get to watch in amazement as big trout erupt on your dry fly, and tear upstream in a violent and powerful run. On days like these you can do no wrong, it’s as if every trophy trout in the river has been waiting all year just to eat your fly. Though, sadly, that’s not the norm. The reason those epic days are so special is because they so rarely happen.

I’ve spent many days watching perfect drifts go unrewarded during the Madison’s salmonfly hatch with perfectly presented stonefly imitations. Over the years I’ve been forced to look past the obvious attraction of the Hollywood Hatch, and look deeper for other ways to feed these crafty trout. More times than not, the answer has been with Arctopsyche grandis.

Arctopsyche grandis is a large (size #8-10) chocolate-colored caddis that is conveniently at its peak of activity on the Madison River when salmonflies are hatching.

A. grandis are predominantly nocturnal, but at their peak abundance, the sheer volume of insects provides an ample supply of unlucky individuals who fall or get blown from stream side vegetation into the drift. Just like Salmonflies, Arctopsyche adults can be seen fluttering haphazardly across the surface, especially close to the banks, on windy afternoons.

Conveniently, many of the Madison’s best brown trout occupy those prime lies along the bank, hunting opportunistically for any and all insects that come their way, not just the immense stoneflies.

I generally prefer to present a single dry fly to these sneaky bank feeders. I like a 10-12 foot leader (depending on wind), with a long 2-3 foot tippet section of soft monofilament. When casting from the drift boat, I find a downstream presentation with a reach cast to be the most effective. When wading, I like to approach from below my target, fishing upstream with an elevated pile cast and a slight reach to the bank side.

Dry fly patterns like a size #10 Royal Stimulator, #10 Micro-Chubby, or #10 PMX are all great searching patterns when Arctopsyche are active. All of these flies are also great imitations for the multitude of smaller stoneflies which are present at these times.

When dry fly fishing isn’t producing, often in the week or so leading up to the hatch, larval imitations of A. grandis can be seriously effective. These large larvae are found in size #8-10 on the Madison with a bright olive body and a dark brown head. Nymph patterns like the BSA Beadhead Caddis Pupa, and a Tungsten King Prince are a great choice.

Don’t get me wrong, on days when the infamous fish on the Madison are crushing Salmonfly dries I will cast them until my arm falls off. But when they’re not, you will most likely find me fishing an Arctopsyche imitation….with a bent rod.

So, keep an eye out for these large, chocolate-colored caddis the next time you’re fishing the Madison during stonefly activity, and keep their imitations on deck if you’re watching too many of your own perfect drifts with a Salmonfly go unrewarded.

Hatch Profile – Pale Morning Duns

Hatch Profile – Pale Morning Duns

Photo:  Kurt Schirmer / Troutnut.com

If you had to pick only one hatch to know and understand in Yellowstone Country it would undoubtedly be the Pale Morning Dun (“PMD”). This group of mayflies is found on every piece of moving water that holds trout, as well as some of the lakes. Populations of PMD’s are strong in all of our major fisheries, providing an ample food source for area trout in the nymph, emerger, dun, and spinner stages of their life cycle.

 Pale Morning Dun is a common term coined by legendary authors Doug Swisher and Carl Richards in their groundbreaking book, Selective Trout in 1971. There are two separate species that make up this important group of mayflies; Ephemerella infrequens and Ephemerella excrucians.

 The larger (size 14-16) Ephemerella infrequens generally emerges first with hatches beginning as early as late-May in some fisheries. Ephemerella excrucians can be found emerging throughout the summer lasting as late as October, and can be as small as a size 20. This progression of emergences with bugs getting smaller through the season is often mistaken for the multi-brooded behavior seen in Baetis and Callibaetis mayflies where spring hatches propagate the bugs that emerge later in the season. Rather than one species that continues to emerge throughout the season spawning progressively smaller individuals, the PMD is actually two distinct species with different sizes and sequential emergences.

 PMD’s are an important food source for trout at each stage of their life cycle. The nymphs are three-tailed, and can be found in a variety of colors ranging from rusty-brown to black. The abdomen of Ephemerella infrequens has a pale yellow dorsal (top) stripe that is very prominent. PMD nymphs exhibit an interesting behavior where they will move from the bottom of the water column to the top several times prior to emergence. These practice runs have been described as “Pulses of Benthic Drift” by entomologists, and can result in some outstanding nymph fishing preceding the hatch. Stay tuned to the blog for a more detailed look at Pulses of Benthic Drift with information on other species that exhibit this behavior and how that can impact our fishing success.

 PMD duns are three-tailed with light-dun colored wings and generally a pale yellow to light olive colored body. During heavy emergences duns can blanket the water, but crippled, stillborn, and other emerger imitations will often outperform the dun, especially with large fish.

 Spinners also have three tails. Their wings are shiny and clear, and the body coloration will range from rusty to olive-brown. Both male and female adults return to the water after mating which results in dense spinner falls when conditions permit.

 Weather plays a critical role in PMD activity and corresponding fishing strategies. As a general rule, the nicer the weather, the earlier and lighter the hatch will be; the scuzzier the weather, the heavier and later the hatch will be. On warm, sunny days you might see a sparse emergence in late morning or early afternoon. Cool, cloudy days with precipitation will yield the longest and thickest hatches, but that may not occur until mid to late afternoon. Calm, warm mornings and evenings produce the best spinner falls. The warmer the weather, the earlier in the am and later in the pm the spinner falls will occur.

 Regardless of the conditions or the time of day, PMD’s are available in large numbers on all of the major fisheries in Yellowstone Country. So, if you find yourself on the water anytime between the end of May and the beginning of October (especially in June and July), and you’re wondering what the trout are feeding on; you should always start by asking yourself “Self, what are the PMD’s doing?”