Regarding orange scuds, here's what I heard from a PSU entomologist (who some of you probably know). Some scuds get infected with a parasite that is orange in color. This parasite can't live inside a scud forever, so it needs to find a new host. Fish/trout are the next step up, so the parasite essentially takes over the brain of the scud and sends signals that cause the scud to leave the cover of vegetation and swim into the open...where it is promptly devoured by a trout. It might sound a bit far-fetched the way I have worded it but hopefully I'm explaining the general idea well enough.
This can be imitated by using an orange hot spot on the scud. I don't think it's quite the same as the entire scud turning orange after death. I've taken a lot of fish on an orange hot spot scud, but haven't used it in enough situations to be able to say for certain that it makes a difference.
Great post Dave. I like to fish scuds actively as opposed to dead drifting, so I will take your observations into account next time I tie!
