Dan Charles

The fields and back roads of eastern Arkansas were a crime scene this past summer. State inspectors stopped alongside fields to pick up dying weeds. They tested the liquids in farmers' pesticide sprayers. In many cases, they found evidence that farmers were using a banned pesticide. Dozens of farmers could face thousands of dollars in fines.

Mike Hayes and I are sitting on the patio of Blue Bank Resort, the business he owns on Reelfoot Lake, in Tennessee. The sun is going down. It's beautiful.

What really catches your eye here is the cypress trees. They line the lake, and thousands of them are standing right in the water. Hayes tells me that they are more than 200 years old.

Robots have taken over many of America's factories. They can explore the depths of the ocean, and other planets. They can play ping-pong.

But can they pick a strawberry?

"You kind of learn, when you get into this — it's really hard to match what humans can do," says Bob Pitzer, an expert on robots and co-founder of a company called Harvest CROO Robotics. (CROO is an acronym. It stands for Computerized Robotic Optimized Obtainer.)

In the global debate over neonicotinoid pesticides, the company that makes most of them has relied on one primary argument to defend its product: The evidence that these chemicals, commonly called "neonics," are harmful to bees has been gathered in artificial conditions, force-feeding bees in the laboratory, rather than in the real world of farm fields.