The private crop insurance industry is blasting a proposed restructuring in the crop insurance program they say would cut $4 billion — or $800 million a year — over the next five years. The proposal, by the U.S. Department of Agriculture and the Risk Management Agency (RMA), which manages the federal insurance program, would also impose as much as $100 million in additional costs on private insurers, according to the National Crop Insurance Services, which represents the 15 insurers participating in the public-private cooperative program.