Ecosystem simplification, biodiversity loss and plant virus emergence

•New plant viruses diseases emerge periodically in crops.•These viruses jump species from other crops, or from wild plants.•The role of biodiversity loss, or ecosystem simplification, in this process is not well understood.•A few clear examples are summarized, but generalization of these principles will require better understanding of plant virus biodiversity.

Plant viruses can emerge into crops from wild plant hosts, or conversely from domestic (crop) plants into wild hosts. Changes in ecosystems, including loss of biodiversity and increases in managed croplands, can impact the emergence of plant virus disease. Although data are limited, in general the loss of biodiversity is thought to contribute to disease emergence. More in-depth studies have been done for human viruses, but studies with plant viruses suggest similar patterns, and indicate that simplification of ecosystems through increased human management may increase the emergence of viral diseases in crops.