Increase of the number of broods of Fall Armyworm (Spodoptera frugiperda) as an indicator of global warming

Abstract

Yield losses are closely related to the increased pests on crops. Higher temperatures can lead to an earlier establishment, shorter life cycles, more generations and spread in a geographic range. Corn is an important economic crop worldwide. One of its main pests, <i>Spodoptera frugiperda</i> (fall armyworm, FAW) is causing losses of millions of dollars. Maps of climatic scenarios show an increase in the number of FAW generations for the study area. While currently three and four generations are the most common, by 2060 four and five generations can occur over most of the state area. In some areas, seven generations can occur within a season; currently, seven generations do not occur in the state but six generations can occur in very small areas. These results show that more days with warm temperatures in a breeding season can lead to a decrease in the FAW life cycle duration, enabling more broods per season. This increase can generate more pressure in agricultural areas with negative economic and social impacts on the corn supply in the future. The results of this modelling could be used to perform mitigation and adaptation policies to guarantee food security under a changing global climate.