Forecasting systems for migrant pests. III. Locusts and grasshoppers in West Africa and Madagascar

Many acridoid species are known to undertake long-distance migratory flights. The migrations of gregarious-phase locusts are a well-known phenomenon but those of solitary locusts and grasshoppers have been observed only relatively recently, over the past 30 or 40 years. For the last 20 years, French scientists now at CIRAD-PRIFAS in Montpellier have studied the factors influencing the migrations of solitary locusts and grasshoppers and their role in the events leading to outbreaks of pest species. The work has led to the development of survey and warning systems for three of these. This chapter describes the work on the Migratory Locust, #Locusta migratoria capito#, in Madagascar (with a brief reference to #L. m. migratorioides# in West Africa), and the Senegalese Grasshopper, #Oedaleus senegalensis#, in West Africa. (Résumé d'auteur