This report summarizes the pesticide assessment for field corn and soybeans in the Corn Belt. Without insecticides, corn rootworm larvae and other soil insects would cause substantial corn yield losses, and Mexican bean beetles would reduce soybean yields. The loss of seed treatments would result in yield losses to both corn and soybeans. Among the herbicides, the loss of triazines would cause the greatest corn yield losses, while either dinitroanilines, acetanilides, or bentazon would cause the greatest soybean yield losses. This report includes pest rankings, estimates of acreages treated with pesticides or other pest management practices, and estimates of pest losses with and without pesticide use, for insects, diseases, nematodes, and weeds.