The Hendrickson Mayfly

Mayflies are essential to trout fly fishing. There are still ultra purists who consider casting dry mayfly patterns upstream to rising trout the ONLY form of fly fishing. I wasn't brought up that way and find that way of thinking too limiting. For one thing it would severely limit my time on the water, and would force me to get rid of about three-fourths of my beloved fly fishing gear. However, I must admit, there is a certain timeless quality to casting classic dry flies upstream to rising trout. And if that were available to me year round, well I might move to closer to ultra purist status.

One of the classic mayfly species is commonly called the Hendrickson. But it's Latin name is Ephemerella subvaria, and then there is the Light Hendrickson and it's Latin name Ephemerella invaria. But it doesn't stop there, there are several species that entomologists have identified. But we as fly fisher's have simplified that and lumped all these into Light Hendrickson and Dark Hendrickson.

How the Hendrickson mayfly received it's common name is a bit of fly fishing lore. As told by Roy Steenrod of Liberty, New York:

'"One day in 1916, while we were fishing the Beaverkill below the junction pool at Roscoe, a hatch of flies came on. We had never seen the fish rise so freely for any fly as they did for this hatch. I caught one of the flies and put it into my fly box, and after lunch that day at Ferdon's I tied some patterns of the fly as nearly as I could. We took fish with fly day in and day out, and for years it proved to be a killer and is so today. One day, while sitting on the bank of the stream perhaps two years after I had tied the first patterns, the matter was brought up as to which I would call or name the fly. Looking at A.E., the best friend a person could ever wish to have, I said, 'the fly is the Hendrickson.' I saw at once that A.E. was pleased.'

The Dark Hendricskon or the Ephemerella subvaria is one of, if not the first substantial hatch on many rivers every spring. When water temperature hits 50 degrees the fish begin seeing and keying on this mayfly. The males and females look very different, while the Dark Hendrickson pattern is a great imitation of the male, the Light Hendrickson is probably closer to the female. However, the classic pattern described above is the Dark Hendrickson, that worked so well all those years ago. And still does today.

The Light Hendrickson pattern is commonly used for two other mayfly hatches. The Ephemerella invaria can also be called Pale evening Dun or Sulphur and is commonly mistaken with the Ephemerella dorithea. But the invaria hatches first, often right after the subvaria or Dark Hendrickson. It is more robust than the later Pale Evening Dun or Sulphur patterns. For most fly angler's however, it is enough to remember Dark Hendrickson first then Light Hendrickson second. Once in a great while angler's will not have any luck on rising trout hitting the Dark Hendrickson, even though it is only the subvaria that is out. Perhaps the trout are keying only on females, for whatever reason switching to the Light Hendrickson seems to do the trick.

One other thing about the Light and Dark Hendrickson fly patterns. Is that they make great general all-purpose mayfly attractor patterns. Renowned fly fishing author Skip Morris, has proposed that only two mayfly patterns are required in one's arsenal a dark and light pattern. While most angler's wouldn't be comfortable with such a limited offering, these two patterns would complement each other just fine. The Dark Hendrickson is second only to the Adams as the most used all purpose mayfly attractor.

Let's also not forget the sub-surface version of these great trout mayflies. The common three patterns that cover the whole Hendrickson family of may flies are as follows. Of course there is the Hendrickson Nymph, which is a close cousin of the all-time great Mayfly nymph the Pheasant Tail.

The Hendrickson's, whichever Mayfly is on the water, are a versatile combination to have in your possession. They can be traced back to when affluent fly fisher's had their own tier's, and they are still used today. Classics never go out of style.

About The Author

Cameron Larsen is a retired commericial fly tier and fly fishing guide. He now operates The Big Y Fly Company - http://www.bigyflyco.com. He can be reached at info@bigyflyco.com.