Never got off topic, you were just assuming they only eat scuds and seem to target them based on that. Wrench started it.
Trout park trout are conditioned to eat pellets, about size 12 to 14. Anything that resembles them will elicit a strike out of competitive reflex. If your reflexes are precise, it will result in a hookup. They have become found of orange or yellow pills, either yarn or cheese, or power bait because of egg ingrained feeding in genes. White jigs have became a staple from the parts floating by from trout cleaning in the stream or decaying parts floating by.
Not many survive to the point to feed like a native. They have been fed little brownish pellet all of their lives in the concrete ponds where they were created. Match the hatch.