Wednesday, August 15, 2012

Serratella's - The Toughest Hatch


Picture this. It's August, you're wading knee deep in the Frying Pan near Mile Marker 6 during a hot afternoon. You're anxious to catch some fish. You hurriedly throw on your waders and boots and grab your fanny pack and rod. You've already made the commitment to yourself that there's not going to be any bait fishing (nymphing) done today. You sit down on the bank observing Mother Nature at her finest. Fish are rising in good numbers on the shady side of the far bank. Being that it's August you feel confident while tying on a #12 Green Drake Sparkledun trailed by a #16 CDC Thorax PMD on 6X fluorocarbon tippet. You know the drill here. These fish are tough, but seem to be rising with reckless abandon as they occasionally even launch themselves completely out of the water. This shouldn't be too hard.

You make your approach from upstream and get to within 40 feet of the pod of rising fish being careful not to spook them. You Dry-Shake your flies and begin getting some line out. You cast 10 feet ahead of the lead rising fish, which seems to be the largest in this street gang. Your drift was about a foot and a half off of where you intended it to be, but your flies are close enough. As your flies sail beyond the fish without so much as even a look, you cast again. This time your flies land exactly where you wanted them to. Your drift is drag free yet again, but no result. Not even so much as a half-hearted look. This time you step your tippet down to 7X. Still, not even a look. Okay, you've been through this chess match many times before. You try a Drake Cripple trailed by a PMD No Hackle. Still nothing. You go through your bag of tricks and try surface emergers, sunken spinners, floating nymphs, ants, 8X tippet, reach casts, downstream drifts and nothing produces. The fish continue to rise. But to what?



You pull out your seine and look at the water with scrutinizing detail. You finally notice some tiny #22 Blue Wing Olive's going down the river mixed in with the significantly larger Drakes and PMD's. Finally, the clue to the riddle. Luckily you have some BWO patterns stashed in your pack and knot on a #22 BWO No Hackle followed by a #22 CDC Winged Baetis. Your next few drifts are spot-on. You finally end up getting a few looks, which is encouraging, but nonetheless you are still skunked and mythed by what is happening. One more cast. You half-heartedly make a cast, your fly swings, and at the end of your drift, BAM, fish on! What the heck just happened, and why?

Welcome to the wonderful world of the infamous Frying Pan Serratella. Serratella's are more commonly well known as a small western dark Hendrickson. They occur in fishable numbers in very select waters including the Frying Pan, Yellowstone and the Henry's Fork of the Snake Rivers. Many entomologists and expert anglers have noted though, that our Serratellas differ from those in other waters. The Serratellas of the Frying Pan are an adaptation that are unique to only the Frying Pan. Upon inspection they appear to be a Blue Wing Olive or Baetis specie of sorts. They are small in size and generally range in hook sizes from #20's through #26's. Much like a Baetis, they have an olive body and short dun colored wings. What makes them unique on the Frying Pan is that they are flightless and hermaphroditic. They hold their egg sack between their wings and scurry along the rivers surface trying to dislodge the egg sack.

As legend has it, upon construction of Ruedi Reservoir and Dam, these insects had to either adapt or become extinct. With the cold river temperatures created by the bottom release reservoir, these insects found numerous ways to survive and adapt to the new conditions. One was to become asexual, another flightless, and yet another being how they deposit their egg sack. Why these insects adapted in such differing ways is beyond any of us. Numerous anglers have stumbled across these unique insects and thought to have discovered a new insect species. Rumors are told of these anglers trying to name this "new" insect after themselves. For example, serratella kirkwebbis, or at that time, ephemerella kirkwebbis. Only in recent years has this insect been classified as a serratella, as it used to be classified as an ephemerella, which is the same family as a Pale Morning Dun. It's common for most amateurs to recognize this insect as a PMD or Red Quill. The defining characteristic as a nymph is the pale dorsal stripe that extends the length its back. Perhaps the easiest way to decipher the serratella from an ephemerella (pmd) is that serratellas lack the lateral fringe of fine hairs along their tails. As an adult insect, the Frying Pan serratella ranges in color from brownish olive to a mahogany brown. The insects that we find on the Frying Pan will range in hook size from #20's to #28's. More often than not, my experience tells me from seine samples that the nymphs are often larger than the duns. An average size nymph is typically about a #20-22, while the duns range in size from #22-24. Though durations and times of this hatch vary from year to year, we typically see them hatch from July though September, during the afternoon hours of noon to three pm. The dog days of August are often the best time to encounter these insects.

According to Frying Pan legend, Roy Palm, the Frying Pan serratella is a hybridized insect. What that hybridization may be or consist of is unknown but probably happened 10 million years ago. Roy notes that these insects are limited to the Frying Pan due to the fact that they can't fly and deposit eggs elsewhere. He also mentions that the serratellas are found throughout the river and not limited to just the middle river, though the middle river certainly has the heaviest hatches and draws the most attention from anglers. I've personally seined decent numbers of serratella nymphs literally right behind the shop. Entomologist, Dr. George Edmunds of the University of Utah was working diligently on classifying this insect years ago, though has since passed away. Dr. Edmunds was so enamored with this insect that he continued to study them well into his 80's. Having studied mayflies from Madagascar, New Guinea and all over the Rocky Mountain West, he suspected that the Serratellas might mate when in their nymphal form. Though many species of serratellas exist, no one has been able to pinpoint this exact specie. Some anglers continue to believe that it's not an entirely new insect but rather just an adaptation. I've never been able to really get a straight answer about these insects from anyone. If you know something we don't, by all means let us know.

Fishing through a serratella hatch baffles many anglers including those who are "well versed" in the ways of the trout. These insects carry somewhat of a cult-like following. Those who chase this hatch are widely regarded as outcasts in the fly fishing community, much like how the salmonfly hatch and its roadies used to be. This small following of Frying Pan serratella anglers has developed techniques and flies that are crucial if not mandatory for success. First and foremost, the biggest key is to fish the beginning and tail end of the hatch when the numbers of insects are less and fish can become more focused and feed in more defined lanes, in addition to your flies not becoming lost amongst the masses. When fishing duns or adults, keep in mind that these critters literally scurry along on the waters surface, thus skating your patterns are needed to induce takes. Think along the same lines as skating caddis adults during spring hatches. I personally prefer casting up and across from the fish, throwing in downstream mend, then continuously shaking my rod tip laterally in short bursts. Some of my favorite commercially available dry flies include the Perfect Baetis, Sprout Baetis and the CDC Wing Baetis. Taylor Creek manager, Will Sands, often recounts a story of how his girlfriend, Nicole, and he were fishing through a serratella hatch a few years ago on the Pan. Nicole just started fly fishing at the time, and was drifting some small bwo's dries over pods of rising fish. She started slamming fish, when no one else on the river could. It took Will a little while to figure it out. After all, he himself was somewhat struggling that day. Finally he was able to put two and two together and noticed that Nicole was not achieving a dead drift as she had been taught, but rather was "accidently" swinging her flies to the fish. This is exactly the behavior that the fish were obviously keying in on. I cannot reiterate the importance of this method enough.

If you are a fly tier the world is your oyster for this hatch as no pattern I've tried or seen has been able to consistently fool fish during this hatch. The body needs to be short and stocky (like a Trico). I like using a brown thread underbody with an olive turkey biot overbody. This color combo seems to match the insects best. If you are dubbing the body try a mix of mahogany and light olive superfine dubbing (1 part mahogany to 4 parts light olive). As far as tailing materials go, both microfibbets and spade hackle fibers are useful materials as well as trailing shucks made of Z-lon or Antron. I'm still partial to opt for a trailing shuck versus a true tail, as many of these insects become stillborn or crippled. The wings on the adults are often held near horizontal instead of vertical. Think along the lines of "jet wings" versus spent "airplane wings" that are cocked upwards but not paired or matching. Remember, an egg sack is held between their wings, thus the reason why their wings are not paired together like other mayflies. These wings are most often light dun colored and are two to three times the length of the body. The well defined egg sack is an obnoxious chartreuse or lime-green in color. As a fly tier I feel that though the fish likely do not see this egg sack, I still like to incorporate into my fly designs for a touch of realism as well as a visual reference for me to visually see my fly on the waters surface. Your flies should be low-riding imitations that float well to enable you to skitter them when being fished. Emerger patterns are generally not of large importance, but when fish key in on this stage general blue wing olive imitations fish well. When imitating the serratella nymph, be sure that your patterns include the pale cream colored dorsal stipe. The Poxyback Baetis tied in black or brown is a proven winner, as are most Pheasant Tail type patterns.


This article is a direct result of numerous customers and clients that have been asking for information on this unique little insect. Many are enamored by the infamous serratella, and many more have been beaten down and downright dumbfounded by this hatch and want to improve their odds out on the river. Gary, Herb, Mike and Mike, Walter, and the rest of the cast of characters, this one is for you. We hope that this article sheds some insight to the complexities of what myself and most others consider the toughest hatch. This hatch is truly a spectacle to behold and fish through. It's damn hard, but extremely rewarding.

Written by Kirk Webb
Taylor Creek Fly Shops

Photos courtesy of Kirk Webb, George Edmunds and Roy Palm