Flies: Zug Bug

Zug Bug Fly Pattern
Zug Bug

If you haven’t noticed by now, there are not a lot of “Hot New Flies” that I feature here. Most of the flies I fish with, particularly in the Smokies, are older, traditional patterns, or possibly an old staple that I’ve put a modern spin on. Maybe that makes me a curmudgeon. I don’t know. But until the old staples quit catching fish…

This month’s fly is no exception. Cliff Zug created the Zug Bug in Pennsylvania in the 1930’s. It originally imitated a cased caddis or caddis larvae but over the years has proven to be a highly successful generic or searching pattern. It’s popularity quickly spread through the Catskills and eventually to the American West. Today it is widely known around the world and is on the “must have” list of patterns for many fly fishermen.

While I have success with this fly throughout the year, it has been, for whatever reason, particularly productive for me in the late winter and early spring. During that time of year, I like to fish it deep and slow through slower pools, typically under a strike indicator. However, it also fishes well later in the year on a swing through pocket water.

It’s relatively easy to tie and is available almost anywhere that sells flies. Bead head versions are also available but I tend to stick with the original, mostly in sizes #16-12. If you don’t know this fly, you should! Play around with a few different sizes and variations and see what you think.

Learn more about Smoky Mountain hatches and flies in my hatch guide.

Flies: Isonychias

Isonychia
Isonychia

The mayfly with the funny name is one worth knowing when it comes to fishing in the late summer and early fall. Actually, all mayflies have funny names, but most, over the years, have become known by some common name such as Light Cahill, Sulfur, March Brown, or Quill Gordon. But the Isonychia still proudly boasts its Latin name. Sure, there are those who might refer to them as Mahogany Duns, Slate Drakes, or even Leadwing Coachman, but none of those names ever stuck.

Isonychia Nymph
Isonychia Nymph

Probably the main reason is that those common names refer more to this insect in its adult stage, but to the trout (and trout fisherman), the nymph is by far the most important stage of this insect’s life. Isonychias, or Iso’s as some call them, don’t behave like most other mayflies when they hatch. Most mayflies will emerge to the surface and hatch in the water near the surface film. After hatching, they are often on the surface for a small amount of time, allowing their wings to dry before they fly off. This leaves most mayfly adults vulnerable to hungry trout and is the stage of the lifecycle that many dry flies represent.

But Iso’s behave more like a stonefly. The nymphs swim to rocks or woody debris and hatch out of the water. The trout never get a shot at the adult until it later returns to lay eggs. Take a closer look at exposed rocks in or around the stream this time of year and you’ll likely see some of their empty shucks.

In the Smokies, they typically hatch from August through October with peak emergence in September. If you want to try your luck imitating them with dry flies, try a dark bodied parachute in size #14-12. The body color will typically be anything from a deep mahogany to dark grey or even black. A good ol’ Parachute Adams is probably as effective as anything. When they return to the water to lay eggs (known as the spinner stage), their body color is more orange or rusty.

George Nymph Fly Pattern
George Nymph

However, as mentioned above, the nymph is what you should be most concerned with. Also in sizes #14-12, the nymph is slender with a dark brown to black body. It has a very distinct white stripe down the back. You will sometimes find specific Isonychia nymph patterns but they are imitated well with common patterns. Prince nymphs or Zug Bugs are a couple of favorites. The late Eddy George was a well-known and highly respected fisherman and fly tyer in this area. He is probably best known for the George Nymph, a fly that I regularly tie and fish in the Smokies. Many people speculate what this fly might represent. With its slender, dark body and white poly-yarn back, it’s incredibly effective during Isonychia time!

Dark soft-hackled wet flies are very productive, too, as Isonychias are active swimmers and tend to be most active in the mornings and evenings. Any time of day is a good time to drop one of the above fly patterns off a dry fly. Early and late in the day, try fishing with one or a pair of these nymphs. Vary your typical dead-drift presentation to offer the occasional twitch or even swing. Check out the Active Nymphing article in this newsletter for more on that presentation.

Learn more about Smoky Mountain hatches and flies in my hatch guide.