The flyfisher's winter evening project for this month involves learning to make cork bugs, and because this writer believes that a size 12 yellow popper with brown hackle and gray tail is about the ultimate for bluegills and bass in the lakes he is acquainted with, it is the one we will tie.

You will need a size 12 humped shank hook, a size 000 bottle cork or a quarter inch cork cylinder 3/8 inch long, a barred mallard flank feather, a brown rooster neck feather, some 2-0 nylon fly tying thread, fly head cement, epoxy glue, and two small bottles of model paint, one white and one yellow.

For tools, a fly tying vise, scissors, razor blade, or sharp knife, hackle plier, dubbing needle and two or three toothpicks will make the job easier.

Using the razor blade, make a slit lengthwise and about a third of the way through the cork selected for the body. Insert the hook in the cork temporarily so you can locate the cut later and place it to one side. It's not a bad idea to prepare and cement a dozen or so corks at one sitting.

Next, mix the epoxy glue according to directions and, after removing the hook, use a toothpick to work a little into the slot in the cork, then push the hook back into the slot (and the glue) with the bend away from the cork and the eye projecting about one-sixteenth of an inch ahead of the popper face. Now tilt the hook slightly so the eye end is buried deepest and as much as possible of the hook gap is left unobstructed. Still using the toothpick, give the whole cork a thin coat of epoxy glue and, after making sure the hook eye is clear, set it aside to dry at room temperature. Covering the cork with epoxy at first will give it, when set, an armor of hard clear plastic. For just one popper, fast drying "five minute" epoxy is all right, but for several the regular slow drying kind should be used, and this takes 12 hours to dry.

After the glue has set, give the cork body a base coat of white and a final coat of yellow. A toothpick can be used to apply the paint. The covering of epoxy and two coats of paint will give a nice smooth finish. The glue, until set, is water soluble, so any excess on tools, fingers or the popper itself can be easily removed with a damp cloth.

After the paint is dry secure the popper in the fly tying vise with the hook bend in the jaws and the cork body projecting to your right. Using a toothpick, put a little head cement on the hook just back of the cork, then wrapping over and away from you, make a base for the tail and hackle by covering about a quarter inch of the hook shank just back of the cork with thread, half-hitch, let the thread hang and put some head cement on the winding.

Cut a clump of fibers from the barred mallard feather as big around as a kitchen match and twice as long as the body cork. Place this on the hook directly on top of the thread base, make two or three winds of thread over it, tighten by pulling straight down, half-hitch, cement, and let the thread hang. Be sure to make all wraps over and away from you. This insures a tightly constructed fly.

Next select a rooster neck hackle feather with fibers roughly one and a half times as long as the hook gap. Prepare this by cutting the webby fibers away from each side of the stem at its base, leaving a row of short barbules on each side. Spread the hackle by stroking the fibers from the tip towards the butt to make them stand out at right angles to the stem.

Fasten the feather, with its concave side away from the hook, directly on top of the previous knot by making two wraps of thread, and a half-hitch over cork and the feather's trimmed butt. Cement this knot, then grasp the feather tip with the hackle plier and wrapping over and away from you, make as many turns of hackle over the tail and around the hook as you can close up against the cork. Take two turns of thread around the hook and feather tip and half-hitch. Put cement on this knot and make three more half-hitches right on top of it and cement again. Cutoff the excess hackle tip, and using the dubbing needle, pick out any stray fibers that were tied down. Cut the thread.

Poppers can be made more nearly weedless by using only the stiffest, most glossy feathers for hackle. Glossy feathers are less water absorbent and stay stiff longer. Ones tied with this hackle can be inched across weed beds and in and out of pockets without hanging up.

It's debatable whether eyes add to a popper's fish catching ability, but if they are to be of any benefit, they should be placed low enough on each side so as to be visible to fish. Most commercially made poppers have them on top which looks good to birds and people but can't do much towards attracting fish.

Red eyes with black pupils look good on yellow poppers. A tool for painting eyes can be made from a toothpick. Cut each end off square, making one about twice as big as the other. Use the large end for the eye proper and the small end for the pupil. Dip it once for each application and wipe clean with a paper towel before each dip.

Although these bugs are known as "poppers" and they will pop if pulled vigorously enough, usually they are most productive when worked very slowly with frequent pauses.

Fish them around weeds and other cover. Work the shoreline and shallows in the evening. Besides being a consistent bluegill producer, they are very effective for bass. The latter usually take these little lures in such a way as to be hooked in the roof of the mouth and the small hooks hold real securely in the gristle there.

After you have made several of this pattern, make some in different sizes and colors to experiment with next summer. You just might hit on a combination that's irresistible.

One final caution. Popper fishing is exciting enough so it's easy to become addicted to it.