With the best hatch of the season fast approaching, I thought it might be helpful for some of the “Newbie’s” to post a few words on the Sulphur Hatch to get them off to a flying start this month… so if anyone has anything to add in the way of tips, tricks, details, etc. PLEASE feel free to chime in!
The months of May and June here in southeastern PA bring forth the greatest event of the fly-fishing season… the SULPHUR HATCH. These yellowish mayflies are actually made up of three (3) different mayfly species; Ephemerella rotunda, E. invaria, and E. dorothea. Most streams in SEPA hold all three (3) species which can be good AND bad. It’s good because it extends the sulphur hatch from 1st/2nd week of May through much of June (most seasons)… and it’s bad because there are subtleties that the fish notice and key on (sometimes) and if the angler does not adjust, he (or she) could be in for a long evening. The good news though, is that the “bad” is well within your control.
First a quick overview of the three (3) players, in order of emergence;
• Ephemerella rotunda: Duns have a medium yellow body color with slight “olive cast” to them… the largest of the three by a hair, could be as large as a size 12 hook size, but a size 14 will do (a true “tweener”)… often hatch out of very swift water (just below riffles)… hatching usually begins around Mother’s Day and lasts 2-3 weeks… hatch most often in late afternoons (4-6 pm)
• Ephemerella invaria: Duns have a yellowish/orange body color … best imitated with a size 14 hook… often hatch out of slightly slower flows than rotunda’s… hatching usually begins around 3rd week in May peaking around Memorial Day (slowing down in June)… hatch most often in early evenings (6-7 pm)
• Ephemerella dorothea: Duns have a pale yellow body color … best imitated with a size 16 hook (sometimes 18)… often hatch out of slower pools… hatching usually begins in last week of May and lasting well into June… hatch most often in evenings (7-8:30 pm), sometimes right at dusk in a quick “blizzard” of activity.
Believe it or not, there are other “yellow” mayflies hatching during these same times as well, but those listed above make up the Sulphur Hatch as most anglers know it. As you can see there are differences between the three and it will save your sanity to have the proper sizes/colors to cover the gamut. At the very least I would carry size 14 dry fly’s in sulphur yellow to cover the rotunda/invaria and size 16 pale yellow imitations to cover the dorothea (some anglers use a Light Cahill for this). To compound the mayhem, in addition to the over-lapping hatch activity, trout will often key on a certain “stage” of emergence from drifting nymphs, to struggling emergers, to floating duns… and just when you think you have THAT all figured out, there could be spent spinners on the water as well!
If you show up to the stream in the mid afternoon and no fish are rising and no insects are on the water (or in the air)… you could be in for some fast action by tying on a Pheasant-tail nymph (size 14-16) and fishing the riffles and runs. Prior to emergence these nymphs will fill the water column as they struggle to reach the surface. Trout will be gorging on them and you will often see flashes in the stream as fish slash from side-to-side engulfing drifting nymphs by the mouthful.
Once a good supply of duns are on the surface the trout will come up for them and the real fun begins with dry flies… fish staging in faster water will be easier targets as they have precious little time to inspect your offering. Trout holding in slower pools will be a bit tougher, but may be larger and you should still dupe them easily with a stealthy “down & across” approach. If the fish refuse your floating dry, try tying an emerger pattern or weightless nymph about 6” off the back of the dry. This will take fish that are targeting these hapless naturals. Some of you may have heard people say that the trout are easier to catch at the beginning of the sulphur hatch but get smarter as the weeks wear on? These are the guys that don’t adjust to the dorothea activity and are missing out big time. The difference in a size 16 or 14 hook may not sound like much, but place the fly’s next to each other and you will see why the trout key on one or the other. Just pay attention to what is on the water and you’ll be OK.
The last piece of the puzzle is the spinnerfall. Again, this can be as frustrating or as rewarding as you want to make it. Personally I take my largest “dry fly caught” trout every season during the spinnerfall. It’s an easy meal and one that large trout rarely pass up. As you survey the stream take notice of the presence of any swarms of “dancing” mayflies over the riffles. These will be egg-laden females preparing to drop their cargo into the drink before dying and dropping in themselves. The males in all likelihood have already fallen, spent from mating activity. During sulphur season this activity most often takes place during the early evening if not right at dark (maybe early morning if air temp’s are too high for mating flights). These mating swarms start out high above the stream surface and if you happen to notice flocks of insect-eating birds (swallows, swifts, nighthawks… maybe bats) high above, you can be pretty sure that a spinnerfall is about an hour away. Sounds complicated but it is surprisingly simple… for this activity I carry just one fly—The Rusty Spinner—in sizes 14-18. Look for subtle risers, often times near the tail ends of pools, just “dimpling’ the surface and float your imitation right down into the waiting jaws of a heavy brown. If rising fish continue to ignore your floating dun, tie on a Rusty Spinner and 9 out of 10 times you will be surprised at the response.
Always keep in mind that ANY and ALL of the above described activities could be going on… sometimes simultaneously! Just be observant, let the trout tell you what they want, and you will enjoy your cigar and cold beverage a LOT more back at the parking area… this I promise.
*NOTE* The referenced taxon above is a bit outdated as the society of entomologists (or whoever they are) have decided that E. invaria and E. rotunda are now the same species (E. invaria)… also they have added a second dorothea to E. dorothea (E. dorothea dorothea). This info is strictly for the angler’s that are over-obsessed with details (like ME for example)… the trout still eat them the same as they always have.