Peanuts in the Midwest?

Every year I grow a new plant in my garden. I'm in Zone 5. This year I planted Virginia Peanuts. I have allowed for the number of hot days suggested. Are there any insects I should watch out for or any special thing I need to feed my plants so they produce? What about when I harvest them? The plants are about 8 inches tall and have pretty yellow flowers on them. Thanks in advance!