Paralep is the scientific "nickname" for the genus Paraleptophlebia. Heavy hatches of these small mayflies are among the first to greet winter-weary ea stern and midwestern anglers. My memories are bright with their April midday hatching amid unexpected afternoon snow showers. The most popular common names for Paraleps are "blue quill" and "slate-winged mahogany dun."

Just before the Hendrickso ns start, you can expect heavy hatches of Paraleptophlebia adoptiva. They will hatch when the water temperatures are approximately 50 degrees F. for a few days. Hatches start as early as 11:00 A.M. and continue through most of the afternoon, with the best activity occurring during the warmest part of the day.

There are over 30 spec ies of Paraleptophlebia, most inhabiting the rivers of the Rockies and west coast. The most significant species in the East and Midwest are P. adoptiva, P. mollis and P. debilis . In the Rockies and on the west coast, it's P. debilis, P. bicornuta and P. packi.

P. adoptiva is very important in the East and Midwest, such as on Pocono, Catskill and Adirondack streams, as well as in the rivers of nor thern Wisconsin and Michigan, including the Upper Peninsula. I have experienced exc ellent Paralep action during the last two weeks of April on the Upper Delaware River, just prior to the Hendrickson (Ephemerella) hatch. Once the Hendricksons get going, the trout may lose their interest for the smaller Paraleps.

Paralep nymphs prefer slow to moderate water, and their stream lined appearance is very similar to those of Baetis and Pseudocloeon. They are most easily recognized by their size (6 to 10mm long) and their long and delicate "forked" gills.

The three-tailed duns hav e dark brown or mahogany bodies (6 to 8mm) and pale-to mediumgray wings, which seem s olid in color. The small hind wings are distinctly oval in shape and are easily distinguished from the minute, ribbon-like hind wings of the teo-tailed Baetis.

Comparaduns are the imitations of choice for the duns, especially in the early season when the body of the dun floats in the film for a long time. On rivers like the West Branch of the Delaware, where their numbers are extremely prolific, you may have to resort to a Compara-emerger with trailing shuck. CDC emergers are also effective and easy to see, but less durable. All patterns should be tied with thin bodies, like the naturals-thickly-dubbed bodies are a definite turnoff with selective, wild trout.

Editors Note: Al Caucci has been a fly fisherman of the hi ghest order for the last three decades. Co-owner of the Delaware River Club Fly fishing Resort, Caucci is owner a nd director of the Al Caucci Flyfishing Schools including the Al Caucci Bahamas Bonesf ish Schools, which he has been running since 1985. Ted Leeson's article "Bonefish 101" in the May/ June '96 issue of Fly Rod and Reel is a tribute to these schools.

Al is co- author (with the late Bob Na stasi) of Comparahatch, Flytyers Color Guide, Instant Mayfly ID Guide, Hatches, and Hatc hes II. Catskill legend Art Flick said of Hatches that it "has so much more than all the others that is should be the last word on the subject." (Trout magazine recently honored Hatches II as one of the 15 most important books of the last 30 years.) Caucci is the creator of the famous "Comparadun" and developer of the comparafly series of patterns with Bob Nastasi.