I think Fred's comments are extremely valid. Until one of us can turn into a fish and then back into a human again, who the heck knows what a fish is thinking?? Lately I have been having tremendous success on trout with an old pattern called Joe's Hopper, which is a rather impressionistic representation of a grasshopper. In fact, I tell non-fly-fisher-persons that I show it to that, no, it doesn't look exactly like a grasshopper, but to a fish looking at it from below, it looks enough like one that they blast it with gusto! (The takes are never subtle, if you know what I mean.) Dave Whitlock even tells in an article in the latest edition of Flyfishing & Tying Journal how he combined parts of a Joe's Hopper with a Muddler Minnow to come up with a "realistic" hopper pattern as his Dave's Hopper - which I have also tied in the past, but which is more complicated and slower to tie with the spun-deer-hair head.
Well, the Joe's Hopper pattern is just hammering 'em for me, including a 12 1/2" brookie this past evening (see my post for a photo) and a 12-fish day on a local stream. Yet, who's to say that more exact imitations wouldn't work as well or even better? I would find it surprising that a fish would have the time, patience, and brainpower to look over a fly and think to itself, "Well, that doesn't have the right number of stripes or the right shade of 'burnt umber' to be a real one so I'm not gonna eat it!" when survival is at stake...on the other hand, those who fish considerably more pressured waters than I favor might well say that if the fly "isn't quite right" the fish will turn their noses up at it. I absolutely hate crowds and the pounded waters they fish so your results may differ...but I think Fred's flies will likely catch loads of fish, especially those big fat southern sunfish that live in Fred's vicinity and take the place of trout quite nicely, as they did for me in the Texas Hill Country, especially the San Marcos River.
Also, beware the "wisdom" of others over your own personal experience. Someone not long ago on here tried to tell the rest of us that we shouldn't tie "eyes" on our flies because, well, the predatory fish that might hit our streamers could see that our fake baitfish were looking at them and "could see them coming", and would therefore refuse our presentations in favor of "eyeless" flies that "couldn't see them coming." Said poor individual had read that in a magazine somewhere, and was practically laughed off of the site by those of us who absolutely HAMMER the fish on our "eyed" streamer patterns (such as the Clouser Minnow and my own Killer Bass Fly). Moral of the story? Don't believe everything that you read just because it was written by an "expert", such as Dave Whitlock who actually violated his own "rule" by creating a MORE realistic grasshopper imitation! You need to go out and throw a lot of fly patterns around yourself on your favorite waters and see what works for YOU.
Jonathon
No matter how big the one you just caught is, there's always a bigger one out there somewhere...