I knew I should have saved this link when I was reading it.
It was a CnR study on trout by some college professor. It was conducted using artificial lures only.They stocked pond A with trout and fished for them. All the fish they caught were put in a nearby pond, pond B. After several stocking and catching cycles they noticed something strange. If you fished pond A without a recent stocking you couldn't catch any of the left over trout, of which there remained about half of what they stocked. But you could go to pond B and always catch trout. In fact they caught the same trout over and over again. Meanwhile if left unstocked, you could never catch a trout from pond A unless it was restocked.
They cofirmed that while some trout will readily and repeatedly take artificial lures, other trout will never take an artificial.
I thought it was a pretty cool study. Right now my 12 year old daughter and her class are participating in the trout in the classroom program. They are raising trout from eggs and watching their development. Then they are released into MDC approved streams in MO.
Pete