Impact of global warming on the distribution of Anastrepha grandis (Diptera: Tephritidae) in Brazil

Abstract

Anastrepha grandis is one of the main pests related to Cucurbitaceae in South and Central America. This study discusses the impact of temperature increase on the number of generations of A. grandis, whose distribution could be aggravated due to temperature increase. Climatic variations were analyzed for reference scenarios obtained from 1961‒1990 and of A2 and B1 climatic change scenarios of the Intergovernmental Panel on Climate Change, in which a less pessimistic scenario (B1) and a more pessimistic scenario (A2) were found. In relation to the reference scenarios, in colder seasons, the southern and southeastern regions are inadequate for the development of A. grandis, presenting one generation at most. In other regions of Brazil, where temperatures are higher throughout the year, the number of generations is at least two, and there is no variation from one climatic season to another. When analyzing the temperature increase, in a more pessimistic scenario (A2), there is a considerable variation in the number of generations, if we take into account three future climate scenarios in which A. grandis practically doubles the number of generations. In relation to a less pessimistic scenario (B1), there is a smaller variation in the number of generations, mainly in the southern region of the country. This variation is more accentuated in southeastern Brazil due to the temperature increase, in which the pest’s number of generations doubles even in colder seasons.