There is, despite the name, nothing urban about Piper City, Ill. It is a farm town with a skyline of grain elevators, a tidy grid of pitch-roofed houses and, a few blocks beyond, endless fields: corn, soybean, corn, soybean, corn, corn, corn, perfectly level, perfectly square, no trees, no cows, no hedgerows, no bare land. In late August of 2013, a man named Joseph Spencer followed a corn-flanked county road northwest from Piper City until his GPS advised him to leave the road altogether and turn onto a gravel track. Spencer, an entomologist who studies farm insects, was looking for a farmer named Scott Wyllie.