Tilapia don't winter at all well. Cold water pretty well does them in. They are, however, extremely prolific. So prolific that I worry about biomass problems during the summer. Then you can possibly have a big mess when they die off in the winter. I'd stick to bluegill as a renewable source of protien.

I have a concern about your present pond. You mention that you stocked bluegill. However, you don't say how many or what the forage base consists of at this time. The only time I've ever seen largemouths follow me around the bank was when they were starving. Throwing grasshoppers should generate bluegill strikes, not bass. You may be ready for a major problem. However, I could be misreading the situation.