Future planthopper management: increasing the resilience of rice systems

The problem of planthoppers in rice—the causes of planthopper outbreaks and the ways of reducing the likelihood of this happening—is determined by the dynamic interaction between features of the natural system and decisions made in the human use system. A model of the resilience of the rice planthopper system is used to provide a conceptual framework to explore this complex relationship, involving features at different scales, including the crop, farm, village, country and international level. The way in which various combinations of these various factors can determine the resilience landscape and whether a particular rice planthopper system is more or less resilient are discussed; that is, whether planthopper populations remain at low levels or whether rice crops are subject to frequent planthopper outbreaks. Historically, in a number of countries, a breakdown in resilience and the occurrence of planthopper outbreaks have resulted from intensive rice production associated with the increasing use of pesticides and fertilisers, as well as susceptible high-yielding varieties. In the final section, the threat to the resilience of the rice planthopper system resulting from further rice crop intensification to feed the increasing world population is discussed. A number of recommendations are proposed on how this threat might be avoided, including the use of more sustainable practices as part of a second green revolution, such as maintaining and enhancing ecosystem services through better management practices, including more selective use of pesticides and ecological engineering. An important challenge is how to coordinate the decisions made by various stakeholders in achieving a harmonised and resilient approach to rice planthopper management in the future