This is the time! Not next week or the week after, this week! It will be tonight at about the time the late afternoon sun slips beneath the spires of spruce on the mountain, or maybe tomorrow night, or the night after — if it’s going to happen at all.

V. Paul Reynolds, Outdoors Columnist

The Hex hatch, or the Green Drake hatch, is long-awaited by all serious trout anglers. When these big ole mayflies materialize on the trout pond, it is a happening. To a trout-loving fly fishermen, a Hex hatch is an adrenaline rush — a sight to behold. In fact, like a solar eclipse or an expanse of northern lights in the winter sky, a true Hex hatch on a trout pond counts as one of those special moments in nature. For a brook trout, these fabled mayflies are a turkey dinner with all the fixin’s — a chance to get the most amount of food for the least amount of effort.

There is an ongoing debate among Maine anglers about what to call these big bugs. Anglers who know a lot more about entomology than I do say that most of us misname the Hex, calling it a Green Drake, as in, “Hey Joe, you really missed it. As soon as the sun set, the pond was covered with Green Drakes. A wicked hatch! Never seen anything to beat it.”

So the question is, I guess, “When is a Green Drake a Green Drake, and when is a Hex a Hex?”

Leighton Wass, a Vermonter and a trout man who loves Maine, is assembling a book soon to be released titled “Fishing the Hex Hatch.” He has really done his homework.

He writes: “A gorgeous mayfly owning the scientific name, Ephemera guttulata, a second cousin to Hexagenia limbata is also called a Green Drake, as is the Hex. As you can see, confusion reigns supreme here.”

He goes on, “Confusing the matter more, this mayfly hatches nearly at the same time as Hex mayflies, and both are often found inhabiting the same water body. Also, these two mayflies are similar in size, with E. guttulata being a tad smaller than the Hex. The easiest way to distinguish the two, with an adult mayfly in hand, is to count the tails. Hex adults have two and E. guttulata (herein to be called the Eastern Green Drake, EGD) have three. Easy peasy. Also, if this mayfly you are eyeing has any hint of light green to it at all it’s an Eastern Green Drake.”

In summary, if a giant mayfly has three tails, a greenish hue, and mottled wings, it is no doubt the Eastern Green Drake, Ephemera guttulata. If a galdarned big mayfly has two tails, no green coloration, and a networked wing design, it’s our megastar, our big cheese, Hexagenia limbata.

Of course, water temperatures affect not only insect hatches but trout behavior. We do know that pond temperatures are unseasonably warm thanks to an early spring. What we don’t know is what impact this all will have on the customary early July Hex hatch, circa 2021, as well as trout-feeding patterns.

The farther north in Maine you go the more likely that the favorable water temperatures will hold a while longer. And who knows? You might get lucky and get in on a Green Drake hatch during a cloudy, humid day. You won’t soon forget it, if it happens.

Oh yes, if you are fortunate enough to hit the Hex hatch, tie on big artificials: Wulffs, Adams, Hornbergs.

V. Paul Reynolds is editor of the Northwoods Sporting Journal. He is also a Maine guide and host of a weekly radio program, “Maine Outdoors,” heard at 7 p.m. Sundays on The Voice of Maine News-Talk Network. He has authored three books; online purchase information is available at www.maineoutdoorpublications.net.