Assessing the feasibility of biological control of locusts and grasshoppers in West Africa: Incorporating the farmers' perspective

A participatory rural appraisal in three West African countries examined the possibility for replacing chemical pesticides to control locusts and grasshoppers with a biological control method based on an indigenous fungal pathogen. The fungus is currently being tested at different sites in the Sahel and in the humid tropics of West Africa. Structured group interviews, individual discussions, and field visits, were used to obtain farmers' perceptions of locust and grasshoppers as crop pests, their quantitative estimation of crop losses, and their willingness to pay for locust control. Farmers as well as plant protection officers generally perceived locusts and grasshoppers as important pests that cause significant damage. Farmers were aware of some of the risks of the use of chemical pesticides, but not of the potential alternatives. The use of the fungus in an oil-formulation and standard Ultra Low Volume (ULV) equipment was demonstrated, and the results discussed with farmers. Their impressions of biological control were favorable, and they expressed an interest in using the technology. Farmers' expressed willingness to pay for locust control is small, but not negligible. Locusts and grasshoppers are very visible pests and thus amenable to pressure from farmers to local administrators, as well as by farmers' relatives in the city on the national government. Therefore, political pressure for locust control is strong, although national governments spend little on it, depending mostly on foreign donors. Donors are increasingly worried about the environmental effect of the large amounts of chemical pesticides used on locust control, and are pushing for more benign alternatives. The results of the present survey indicate that there may be a potential market for a biopesticide against grasshoppers and locusts on cash crops in the humid areas. The potential market in the Sahel depends on a reduction of costs or a subsidy of its price. This subsidy could be justified by the expected reduction in environmental and health costs when replacing chemical pesticides. Since donors are the current purchasers of chemical pesticides for the Sahel, they would also be expected to be involved in the purchase of the biological product. © 2001 Kluwer Academic Publishers.