Oh, I agree, early spring while suckers are spawning, they work on wild browns. I've even located pods of spawning suckers on gravel and observed the browns milling around behind them. Then caught them with "match the egg hatch" tactics. But the rest of the year, I've tried it, and nada.
But they do work on wild bows too. Year round, not just when suckers are spawning. I had a heck of a day once on Falling Springs, in late July. Figuring I'd fool around after the tricos fell and it was like cheating. Supposedly parsnickerty wild fish going nuts at mid day in mid summer for some salmon colored yarn, lol, was quite a contrast to the tiny fly game I was doing an hr earlier. And I don't fish FSB much. A few other wild bow streams too, and when what you should use isn't obvious, its a confidence fly for me when bows are present. I say fly, but I use glo bugs and sucker spawn more or less interchangably. Both easy to tie but glo bugs are quicker. I think sucker spawn is easier to incorporate weight though, and these patterns tend to need some weight to get em down.
Plus there's the whole lake run scene where egg patterns in general are kind of the de facto standard. To the point that catching them on a nymph or streamer is the "try something they haven't seen" way to go.
I've tried them on brookie streams too, year round. They work. Not any better, and perhaps not as well, as almost anything else though. Put anything in front of those fish withkut spooking them first and they'll take.
