By Leighton Wass Strawberry season in June and July is eagerly awaited by shortcake lovers. This time of year, many of us anglers look forward to another “season” – the Hex Hatch, or as many Mainers call it, the Green Drake Hatch.
By Leighton Wass
Strawberry season in June and July is eagerly awaited by us shortbread lovers. This time of year, many of us anglers look forward to another “season” – the Hex Hatch, or as many Mainers call it, the Green Drake Hatch.
This long-awaited outbreak is generated by a huge mayfly that scientists have named Hexagenia limbata. It belongs to a group of mayflies in which the nymphs burrow into the bottom sediments of many lakes and ponds in Maine. After two years of benthic life, the nearly 2-inch nymphs swim to the surface to hatch into elegant hexagonal mayflies called duns.
Females are about 2 inches long, counting both tails and the body, while males are a bit shorter. Both sexes are colored with shades of yellow and tan. Sorry folks, no green on this species.
Confusion reigns supreme among some mayflies since fly fishermen also use the word “green” to name several other species of similar size. One of them, the Eastern Green Drake (Ephemera guttulata) is also commonly called a Green Drake, but it is not the same creature.
The surest way to tell the difference is to count the number of tails: adult Hex mayflies have only two tails, while the green Eastern Drake has three. (Photos of mayflies are often mislabeled on the internet).
Compounding the problem is that the two species often overlap at the same time of year when hatching, although Maine has very few waters that harbor the Eastern Three-tailed Green Drakes that like limestone.
Why be so excited about the Hexagenia (Green Drake) hatch? This is because these large mayflies offer a very good protein package, which brings large fish to the surface like a magnet. And that means fly anglers have a chance of landing trophy dry fly trout. In my mind, it rarely gets better than that. I call it Hexitis.
Adult Hex mayflies only live for about two days, and during that time Hex duns transform into their last phase, called a spinner. The male and female spinners mate in a ritual flight, followed by the females depositing their eggs in the water, then both adults die. The life cycle continues as the eggs hatch into nymphs which tunnel through the bottom silt and mud.
When can fly anglers expect to see Hex Mayflies? Reports from the Greenville area indicate that the outbreak has already started on local ponds, appearing during the week of June 20. Hex hatches on small, shallow ponds occur first, with deep lakes and high-altitude waters occurring somewhat later.
In recent years, the last week of June and the first week of July have always been good bets, but more recently the trend has been for this outbreak to start earlier in the year. I believe it’s because of this bugaboo – climate change.
The two most important factors that determine hatch onset and hatch duration (in days) are ambient air temperature, which then determines water temperature. Several days with very high temperatures (80 to 90 degrees Fahrenheit) usually mean an earlier hatch, while cold, rainy weather tends to delay it.
The heat from the blast furnace during hatching usually brings it to a short end, a week or less, but more usually it lasts 10 days to two weeks. I have found that most hex traps start when surface temperatures are between 65 and 70 degrees.
Hexagenia mayflies are eaten by all kinds of fish, both nymphal and adult, but in Maine, the species of fish most often targeted by fly anglers is squaretail trout.
There is a downside to fly fishing this sacred trapdoor. The majority of Hex mayflies come out of near dark water, and the time it takes to land the fish when they come up is short, maybe 15-30 minutes if you’re lucky. As a result, an angler should be fully prepared and should not waste time during hatching tying new flies or untangling lines and fly rods. If you’re using a canoe, I recommend you take two ready-made fly rods. When I fish from a boat, I take three fly rods all rigged for action. Time is running out during this outbreak!
Using dry flies is the classic way to fish for salmonids in a hex hatch, but I don’t always find them that difficult. Every Hex angler has a favorite fly, but the truth is that many different flies are catching fish during this hatch. A few favorites are Wulffs, Comparaduns, Hex Dry Flies, Hex Emergers, Hex Rubber Legs, and Stimulators. Hex nymphs can also trick trout before and during a hatch, using either a sinking line or a floating line on a 9 1/2 foot fly rod.
When fishing this trap, be sure to direct the cruising fish when casting, check the fly occasionally for tangles, and if you have the patience, cast and wait…and wait…for the fish to come to you . That works. Also, take plenty of bug dope and don’t bother with the Solunar table.
Maine has hundreds of waters supporting the Hex Hatch. A few are Sourdnahunk Lake, Pierce Pond, the Deboullie area, and the majority of the ponds in Baxter State Park. There are also many quality sports camps that cater to Hex Hatch fly anglers including Bradford Camps, Red River Camps, Nahmakanta Lake Camps, Cobb’s Pierce Pond Camps and Camps from Grant’s Kennebago.