Larry- Knowing that you're fishing ponds and targeting panfish, I can tell you that they will become increasingly difficult to pattern as the water continues to cool. Their forays into the shallows will become less frequent, and as the pond keeps cooling and eventually turns over (if deep enough), they'll be found as deep as 15 or 20 feet.
What does this mean for a flyfisher? Well, if you experience a couple of warm days, the fishing will be more predictable and the chances of the panfish being shallow are greater. However, if the weather remains cool for a stable period, the fish will be deep and not prone to taking anything from the surface. I think that you have the right approach with the scud. It's a great all around fly, and with a bead head and/or sinktip line it can probe deeper water well.
Also, as the water cools the fish will eventually begin to slow down. Their metabolism will match the waters around them (being cold-blooded), so your retrieve of the fly will have to slow down accordingly. When the metabolism slows, they don't have to feed as often, so you really need to bonk 'em on the nose with your offering.
This isn't to say that they can't be caught. But it certainly isn't as easy as it was in the spring or summer. And if you're pursuing perch, they stay more active than the other panfish species in colder water. They're often the first panfish I catch in spring, and the last that I catch in autumn.
Good luck and have fun.