Page 1 of 1

Fluorescent Flies, by Joseph Keene 1964

PostPosted: Wed May 22, 2019 5:03 pm
by Karl Klavon
I have a copy of Fluorescent Flies, written by Joseph Keen and published in the UK in1964, and it contains some pretty impressive information on the advantages and pitfalls of using fluorescent fly tying materials and their abilities to catch fish.

Test #1: The first test Keen conducted was done on pet carp living in an ornamental fishpond. These carp were fed flour and water dough balls regularly, so it was a food form they were well familiar with. Keen made up a batch of dough cylinders with white dyed fluorescent wool mixed into the dough, which made it whiter and brighter than the regular spherical dough balls that the fish were used to feeding on. Equal numbers of the dough ball types were lowered into the pond in a brown mesh net, supported by cords at each corner, and the fish were given 4 hours to feed upon the dough pellets and cylinders. When the net was retrieved the remaining pellets were counted, 70% of the remaining dough balls were of the non-fluorescent type.

Test #2: In this test 8 aquarium minnows were used. The aquarium had a false bottom of metal mesh that the pellets would sink down through, so the fish had to eat the pellets as they sank or do without. Prior to the test the fish were not fed for two days, so they were hungry. On the 3rd day the minnows were offered live dyed yellow maggots, half having FL-yellow floss rings tied around their bodies, and the other half being plain yellow maggots. Once all the maggots that were not eaten settled to the bottom of the fish tank, the minnows were removed and the tank was drained, with the remaining maggots separated out by type and counted. The result was that 75% of the not eaten maggots turned out to be the yellow non-fluorescent ones.

Test #3: The next day the test was repeated. Only this time with regular white maggots, with half having a ring of Red-Fluorescent Floss tied around them, which were readily taken with great enthusiasm by the fully fed minnows, very few of the non-floss maggots were eaten at all.

Test #4: Next, a retest of the white Maggots was done again using rings made of standard red silk floss instead of the FL-Red kind, which yielded almost completely negative fish taking results. But repeating the white maggot test again with rings of FL-Red Floss with the tag ends left on and long, actually repelled the fish from taking the maggots so tied at all.

Stream Testing on Dace: Dace are highly cooperative fish test subjects, quite willing to take almost any fly that floats over them. By constructing a 6 foot tapered leader with a 4 inch dropper, the fish would get to see two flies at more or less the same time and distance, and the Dace would get to choose which one they preferred to take. The fly pattern platform used for this test was Skue’s Spring Olive Mayfly, dry fly, on #16 hooks, with models including slight pinches of FL-Red, FL-Green and FL-Yellow in the dubbing blends as opposed to his standard tie with no FL-materials used, with one of each style for the Dace to choose between.

Dace Test Results: In 24 hours of fishing over two days, 349 dace were caught on the flies with a slight amount of FL-material added to their dubbing mixes. As opposed to only 27 Dace being caught on the same flies that had no Fluorescent material included in their dubbing blends, more or less seen at the same time and at the same distances apart by the fish.

The First Stream Test On Trout: Encouraged by his earlier successes with FL-materials and (evidently) forgetting about the maggot test with the FL-Red floss tag-ends being left long actually repelling the minnows, Keen tied up a lot of fly patterns for trout including bright Fluorescent tags, butts, ribs and collars, all of which did manage to catch a few fish but were not nearly as effective as he was in the minnow and Dace tests. Eventually coming to his senses, Keen did develop tying techniques that mixed the FL-Materials in with standard ones enough to tone the Fluorescence down where the fly patterns would get the results he was looking for.

Conclusions: A rule of thumb I use is that the FL-materials should never exceed 30% of the total surface area of the fly being tied. And I like these FL-Hot-Spots to be over laid with highly mobile Non-FL fly tying materials as an action filter, and also for the Hot Spot be located near the business end of the hook. May you always have Tight Lines on your fish.