Guys and Dolls: How to Match the Hendrickson Hatch(es)

Written by: Ted Fauceglia

For the ardent dry-fly angler, the advent of the spring trout-fishing season stirs feelings of anticipation like nothing else. Sure, dredging weighted stonefly nymphs and Woolly Buggers through winter’s swollen streams and swift riffles is fun and provides some relief from cabin fever, but the spring hatches and the anticipation of casting a carefully tied parachute to rising trout are ever-present. April cannot get here fast enough.

By mid-April, the quiescent, seemingly lifeless waters of late fall and winter are in the midst of a dramatic transformation. The streams and their surroundings now boast an array of brilliant colors and intense activity–both plant and animal life have awoken. Gray skies have turned blue. Scarlet male cardinals establish their territories by singing from the highest branches, while black-capped chickadees cheerfully search the lower elevations for the right tree in which to carve out a nesting cavity.

At ground level, an array of perennial wildflowers is in full bloom–rich yellow marsh marigolds, stately green jack-in-the pulpits, and pure white trilliums. Beside the stream, you may find delicate dog-toothed violets, better known as trout lilies because their leaf markings match the markings of both brook and brown trout.

Hatch Tracking

In the midst of this reawakening and to the fly fisherman’s delight, the annual cycle of spring mayfly hatches, including blue-winged olives, blue quills, quill Gordons, and Hendricksons is also in progess. Known collectively as blue duns, these aquatic insects are, however, distinctly different species, which belong to different families. And despite the fact that they all have opaque blue wings, the individual species can easily be identified by size and color.

The male Hendrickson dun is called the “Dark Hendrickson” for good reason.

According to most published hatching schedules, the individual spring hatches occur sequentially. Olives are on the water first, followed by quill Gordons, blue quills, and Hendricksons. And while I’ve found that nature generally coincides with the hatch charts, more often than not, I’ve confronted conditions where the hatches overlap. In some cases, male and female duns of two or more species were on the water concurrently. On several occasions, all four species hatched simultaneously.

Depending on the weather and the region, these spring hatches can occur any time from the beginning of April to the first of June. In our southernmost streams, such as those in Georgia and North Carolina, emergences start in early to mid-April, while the hatches in northern regions (Michigan, for example) occur in mid- to late May. In Pennsylvania, the Hendricksons are generally on the water from mid- to late April.

There are two prerequisites for successfully dealing with multiple hatches, in any season: You must determine which bug the trout are eating, and you must have the right pattern. Sounds easy, right? It’s not. Notwithstanding the fact that there is an abundance of duns on the water, early-season trout can be extremely selective. After struggling through the winter with only a meager supply of readily accessible food, it’s reasonable to assume that they would gobble up every insect in sight. But they don’t. They are often extraordinarily wary and selective.

In my experience with the spring hatches, trout have invariably keyed on one species. And it’s not always the largest or most abundant species. Casting a blue-quill pattern to rising trout that are feeding on olive duns won’t work–despite the fact that there are blue quill duns on the water. You might get one quick, cursory look at blue-quill imitation the first time it passes over a fish, but that’s usually the end of it. If the fish won’t take a natural blue quill, they surely won’t take an imitation of it.

Female Hendrickson Dun
Hook: TMC 100sp BL, sizes 10 to 14.
Thread: Cahill 8/0 or 70-denier.
Wing: Medium-dun Para Post.
Tails: Light dun microfibetts.
Abdomen: Cream/olive rabbit dubbing.
Hackle: Sandy dun.
Thorax: Cream/olive rabbit dubbing.
Head: Tying thread.

From a distance, it is not usually possible to determine what bug the trout are taking. Dialing in on the right pattern, therefore, is often a process of elimination. Consistently casting the wrong pattern during a multiple hatch will quickly turn anticipation and excitement into frustration and despair, so using a two dry-fly rig will help you to figure out the correct pattern more quickly.

Twice the Fun

The presence of Hendrickson duns in multiple hatches exacerbates the multiple-hatch problem. In most mayfly species, the physical differences between the male and female duns are insignificant. There are slight variations in size and color between the sexes, but the differences are important only to the entomologists. To the trout, the differences are imperceptible–one dun pattern representing each hatch will work for both the males and females. Not so with Hendricksons, because the variation in the color of males and females are obvious. Experience has taught me that the trout know and recognize differences, so I use two distinctly different patterns to match them.

Although most anglers refer to the annual event emergence of Ephemerella subvaria as the “Hendrickson hatch,” the differences in colors between the males and females are so evident that the sexes have been individually named. The cream-colored females are recognized as Hendricksons or Light Hendricksons, while the reddish brown males are identified as Red Quills or Dark Hendricksons. As a rule, you can match the hatches in most regions with patterns tied in sizes 12 and 14. Because the size of the naturals can vary from stream to stream, however, I carry patterns for both males and females in sizes 14 through 10. Also, there are variations in colors from region to region, so you may need to experiment with patterns that are slightly lighter or darker.

Male Hendrickson Dun
Hook: TMC 100sp BL, sizes 12 to 16.
Thread: Camel 8/0 or 70-denier.
Wing: Dark gray Para Post.
Tails: Dark gray hackle fibers.
Abdomen: Red/brown rabbit dubbing.
Hackle: Dark dun.
Thorax: Red/brown rabbit dubbing.
Head: Tying thread.

To fish a Hendrickson hatch properly, then, you must treat it as two hatches. If Hendrickson duns are the only bugs on the water, you have to choose between two patterns–a Light Hendrickson or Red Quill pattern. However, if there are two or more hatches on the water simultaneously, things get more complicated. To deal with this problem, I treat all the spring hatches as a single event. I tie and carry a selection of patterns, in several sizes and colors, to imitate blue-winged olives, blue quills, quill Gordons, and both sexes of Hendricksons.

Because all these insects emerge in riffles or the faster sections of a stream, most of the feeding activity occurs in fast water. Individual trout move to a holding position in the center of the stream and take the bugs as they pass by. A conventional imitative pattern will usually take trout in the riffles because the fish simply don’t have much time to study it before they have to make a decision. However, some trout move to the calmer water and side eddies, where they leisurely sip the bugs that have drifted into the slower water.

Parachute patterns have proved to be my most productive flies for the spring mayfly hatches, especially for fish in flat water. And if they are tied with high-quality hackle and are thoroughly saturated with floatant, parachute flies float equally well in the faster sections of a stream. I think that the success of parachute flies can be attributed to the way that they sit on the water like a natural, presenting a realistic profile to the trout.

Ted Fauceglia is the country’s foremost photographer of aquatic insects, and he writes the “Natural Reflections” column in each issue of American Angler. Ted is also an FFI Certified Casting Instructor, the author of Mayflies (2004), and he has provided the bug and fly-pattern photography for dozens of books.