Fly rodders often start tying flies this month and work through winter to replenish boxes before fly-fishing picks up in early April, often outings that are more symbolic than productive with all the ice and snow.

For folks planning on constructing nymph imitations now, here’s a solid tying tip from the late Joe Brooks (1901-72) that makes sense: In the mid-20th century, this fly-fishing writer advocated using nymph patterns with collars and round bodies instead of beards and flat bodies, so no matter which way the fly tipped in river-current vagaries, the imitation offered the same body and legs silhouette to trout watching from their lies. Brooks’ solid advice has fallen along the wayside.

When tiers construct a flat-bodied nymph, Brooks felt the fly looked odd to fish when it tilted sideways, because wary trout know the cockeyed fly is bogus. Streamside observation and underwater video show aquatic larvae seldom tip sideways in the flow – except in pocket water with powerful, shifting currents that swirl and tumble the bugs. In average flows, natural aquatic larvae stay upright, with bellies parallel to bottom.

Dead-drifted nymph imitations really tip sideways in the current, but if fly rodders cast quartering across and downstream, allow a nymph to swing in an arc on a tight line and then retrieve it upstream, the current pulling on the fly and line keeps the imitation upright more consistently.

In the 20th century’s first half, fly-casting presentations that quartered across and downstream dominated, so flies tipping in the current proved less of a problem. By the 1970s, though, fly rodders, including me, were dead-drifting nymphs like maniacs, a presentation that easily tipped.

Two points about flat-bodied nymph imitations have made an impression on me, and the first one began after reading Brooks’ round-bodied-nymph theory so many years ago:

• As a teenager, I often asked folks a stupid question: If flat nymph patterns are rare, why make a big deal out of round vs. flat flies? Why is that question stupid? Well, flat nymph imitations may have been unpopular in my teens and 20s, but way back in the 1920s through the early 1940s, flat larvae imitations were ever so popular in fly-fishing meccas such as New York’s Catskills and Pennsylvania’s spring creeks, and why not?

Natural clinging and crawling mayflies are flat, particularly clingers. Observant fly rodders noticed the bugs and used Hewitt Nymphs with flattened-lead bodies as an underbase, squashed with pliers and sealed with head cement. Tiers wrapped yellow, green or orange floss over the lead and painted the backs black, leaving color on the bellies. These patterns proved popular in the 1920s-40s and came back a second time in the late 1970s.

Here’s another popular flat-bodied design. Skilled tiers made nymphs wider and flatter by tying common pins or straight pieces of copper or lead wire on both sides of the shank and wrapping the thread evenly over the metal before coating with head cement and then constructing the body.

• In the 1980s, I wrote several articles for Fly Fisherman magazine and kept mentioning Mustad hooks. My Mustad references disgusted managerial types at an English company, one of the world’s most prestigious hook manufacturers. They sent me a complete collection of hooks to show the exquisite quality of the product. The gift included flat-bodied-hook designs with two shanks that looked like a narrow, kite-shaped diamond with a short triangle on the front end and long triangle on the back.

I knew better. I really did, but I started tying flat-bodied nymphs on those flat hooks anyway. And they did look good! Who knew the truth about the design’s shortcomings? Well, Joe Brooks did. And he had told us for decades in books and magazines.

My nymphs impressed folks who saw them, and they would say, “Those look nice.” The open space between the two shanks helped them look exquisite, because it was easy to place weighted wire between the double shanks and evenly wrap silk thread over the shanks and weight. The thread was smooth and tidy for the abdomen and thorax.

Yes, the flat nymphs sitting on Styrofoam beside my tying vise reeked of aesthetics, but when dead-drifting them in various Maine rivers, I had terrible luck catching fish. Even on a catch-and-release river with lots of hungry brookies, browns and splake, these flat nymphs worked poorly for me, and fly rodders who impressed me with their knowledge and skill were also adamant that the flat-bodied nymphs didn’t do well for them, either.

Brooks’ round-bodied nymph theory strikes me as solid info, and in the 20th century and late 19th century, fly rodders in England and the U.S. went through at least two flat-bodied-nymph revolutions that caught the fancy of fly rodders before folks again figured it out. It seems every generation must discover first-hand whether something does or does not work. Indeed, fly fishers repeat mistakes of the past, and I’m one of them.

Ken Allen, of Belgrade Lakes, a writer, editor and photographer, may be reached at:

KAllyn800@yahoo.com