FWIW - In my experience, with my small bodies of water in MN, here are my observations over the last 8 years with BCP and their eating habits...they love to eat small BG.
My pond is full of BCP preferred foods such as dragon fly nymphs, May flyes, Pale Morning Dun, and every other bug hatched in MN waters. I seem to have a new bug hatch once a week throught out the summer (sure wish I knew an entomologist that lived close by).
With all the insects my BCP are still very agressive on the smaller BG. We have done some fishing "experiments" with different sized BG and the harvest size of the BCP. In my experience .5-1" BG were preferred greatly over any other minnow.
This season (6 year olds) my BCP will break the 12"-1lb mark. I know its not the greatest growth rate but I believe the large amount of small BG's have contributed to their growth.
