John Scott's various FEB (Furled Extended Body) flies caught my attention some months ago. I decided to give the concept a try for some of the larger bugs that hatch around here. I still haven't mastered incorporating the tails into the extended body, but I have had some good success this year with FEB nymphs omitting the tails.

In the spring we have salmon flies (ie, giant black stoneflies) that hatch on a few of our streams. These are large flies -- the nymphs that I have measured are around 20 mmm long. I had had good success with a Pat's Rubber Legs tied with black body and black / orange legs. So I decided to try the same basic fly but tied on shorter hook with a furled extended body. This worked really well for me on multiple occasions this spring. The furled body was very durable and I think it gave the body some extra, more natural movement especially in the heavy runs and pocketwater where you expect to find stonefly nymphs.

More recently, I've been fishing Isonychia FEB nymphs. On a recent outing, I caught around a dozen fish includings a 20", 17" and 16" brown in a morning of fishing with all of of these on a FEB Isonychia nymph. As most of you probably know Isonychia are fairly large (12-15 mm) and very active swimmers -- characteristics which make them good candidates for a FEB nymph. My Isonychia FEB nymph is as shown below.
Hook: 12 or 14 scud hook
Abdomen: wine colored sparkle yarn, furled
Wingcase: fine pearl mylar over black mylar braid
Thorax: Isonychia dubbing mix (black with brown and a little red)

So thanks to John Scott I'm now a convert. The FEB style has worked exceptionally well for me with larger nymphs such as mayfly drakes and stoneflies and for those that are active, strong swimmers. While furling was new to me and initially a little intimidating, I've found it to be very quick and easy -- much faster than other extended body techniques -- and the flies are quite durable.