OPERATIONAL-SCALE APPLICATION OF ENTOMOPATHOGENIC FUNGI FOR CONTROL OF SAHELIAN GRASSHOPPERS

Locusts and grasshoppers regularly threaten agricultural production ac ross large parts of the developed and developing worlds. Recent concer ns over the health and environmental impacts of standard chemical cont rol measures have led to a demand for alternative, more environmentall y benign control technologies. Here we present the results of a field study to investigate the potential of inundative biological control fo r control of grasshoppers in the Sahelian region of Africa. The biocon trol agent was an oil-based biopesticide formulation of a naturally oc curring entomopathogenic fungus, Metarhizium flavoviride. This was app lied at a rate of 21 ha(-1) to a total area of 150 ha using standard e quipment normally used for the application of chemical pesticides. Twe nty-one days after application, an 80% reduction in grasshopper popula tions was recorded in treated plots, relative to control populations i n equivalent unsprayed areas. We think that this is the first operatio nal-scale application of a biopesticide to demonstrate significant pop ulation reductions of key Sahelian grasshopper pests. This represents a substantial development in locust and grasshopper control, and shoul d open the way for a new era of integrated control strategies where re liance on conventional chemicals is reduced.