About the cover: Agriculture in North America has been dramatically influenced by crops and pests carried by humans, either intentionally or accidentally into the region. Corn, or maize, probably originated in Central America. It was a staple crop of many Native Americans and was grown in dozens of shapes and colors. The European corn borer originated in Eurasia and was accidentally introduced into North America during the early 1~OOs. This insect readily adopted corn as a host and has since caused hundreds of millions of dollars in crop losses. The photograph of the European corn borer on Indian corn represents the interaction of two living organisms from two continents: one to the benefit and the other to the detriment of humanity