I’ve always wished there was enough free time and adequate resources to take the month of May off and just go fishing. Most of us can’t do that, but we can fantasize.

Why May? It seems that in the evolution of all things aquatic the great spirit of rivers chose May as the month for the most important species of aquatic insects to hatch and continue their kind. And from  the biological/environmental standpoint, that makes complete sense. May has the flow conditions and water temperatures most conducive to the production and maintenance of all these species. May is a beautiful month to be in the Catskills with the snow and cold of winter all but gone. May has warm, but not hot days, and cool nights; the trees are leafed out and spring flowers are in bloom everywhere.

More importantly, from a fishing standpoint, May is the best month for fly fishers. River temperatures have warmed and flows have dropped, creating conditions that will allow for the biggest and best hatches of the Catskill season. May insect hatches begin with late April’s remnants of Hendricksons, red quills, blue quills and their associated spinner falls. With them, fly fishing has begun in earnest in the Catskills.

There are two species of pale evening duns that hatch next. One is related to Hendrickson; the other is quill Gordon. Many anglers call them sulphurs, but they’re not. Both species are size 16 and have a greenish/dun cast to the bodies with a very light-slate-colored wing. True sulphurs are smaller, have a sulphur-colored body and a golden wing, and emerge later in the season.

On freestone rivers, hatches of these two species are right at dusk, but on colder tailwaters emergence is right around 5 p.m. For reasons I don’t understand, trout don’t bother with the nymphs or emergers of either species and feed almost exclusively on the duns. As a result, the dry-fly angler is in for a real treat. I have had some of my best fishing during these hatches.

After those flies, anglers should look for March browns and grey foxes. March browns are bigger than grey foxes, but hatches overlap, with emergence beginning in late morning and continuing sporadically throughout the day. Compared to Hendricksons, these are not large hatches. But the flies are big and draw large trout to the surface. Spinner falls are erratic, with mating adults flirting above the water, only to disappear and return the next night. Anglers fortunate enough to hit it right and witness actual spinner falls are in for some excellent but difficult fishing, because March browns/grey foxes mate, lay eggs and die at dusk.

Finally, right around Memorial Day, anglers will be treated to the largest hatches of the season, with the emergence of green and brown drakes. Fishing can be difficult during these hatches due to the insects’ large size and numbers, coupled with the fact that spinner falls often occur during the hatch. Nevertheless, the emergences of these flies is a spectacle to behold and should not be missed.

In addition to mayflies, there are a variety of caddis that hatch during May, most notably the American grannom and little black caddis. Anglers should have imitations of both, because on more than one occasion I’ve observed trout feeding exclusively on caddis and not on hatching mayflies.

So May is the month with a glut of food for trout to feed on and anglers to fish to: a  cornucopia of fly life that will diminish considerably as the season progresses. Fly fishers should be on the river as often as possible in May; it is truly the best month.