CR prepress abstract  -  doi: 10.3354/cr00744

ABSTRACT: The Desert Locust represents a serious threat to food security in many African, Middle East and Southwest Asian countries. Desert Locust breeding, maturation and diffusion are strongly influenced by local environmental parameters, mainly rainfall, temperature, wind and related features such as soil humidity and vegetation development. The recurring simultaneous occurrence of outbreaks and seasonal breeding over wide regions suggests the existence of large scale forcing due to climatic anomalies. Even if the connections between climate anomalies and Desert Locust upsurges have been hypothesized in literature, no inference has been demonstrated for large scale climatic processes, allowing their potential use as predictors. In this work a historical data series on Desert Locust population dynamics has been assessed by integrating several data sources. A climatic analysis has been carried out on a monthly basis covering the 1979 - 2005 period using the global NCEP-DOE Reanalysis dataset. The Wilcoxon non-parametric test has been used to establish if identified West African atmospheric patterns, in upsurge years, do present significant differences compared to recession years. The analysis suggests a statistically significant role of a weaker easterly flow at African Easterly Jet core during spring, coupled with stronger westerly moisture advection. These climatic features may indeed explain meteorological conditions supporting many contemporaneous outbreaks, eventually developing into an upsurge (i.e. widespread rainfall events over key areas).