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

A participatory rural appraisal inthree West African countries examined thepossibility for replacing chemical pesticidesto control locusts and grasshoppers with abiological control method based on anindigenous fungal pathogen. The fungus iscurrently being tested at different sites inthe Sahel and in the humid tropics of WestAfrica. Structured group interviews, individualdiscussions, and field visits, were used toobtain farmers' perceptions of locust andgrasshoppers as crop pests, their quantitativeestimation of crop losses, and theirwillingness to pay for locust control. Farmersas well as plant protection officers generallyperceived locusts and grasshoppers as importantpests that cause significant damage. Farmerswere aware of some of the risks of the use ofchemical pesticides, but not of the potentialalternatives. The use of the fungus in anoil-formulation and standard Ultra Low Volume(ULV) equipment was demonstrated, and theresults discussed with farmers. Theirimpressions of biological control werefavorable, and they expressed an interest inusing the technology. Farmers' expressedwillingness to pay for locust control is small,but not negligible. Locusts and grasshoppersare very visible pests and thus amenable topressure from farmers to local administrators,as well as by farmers' relatives in the city onthe national government. Therefore, politicalpressure for locust control is strong, althoughnational governments spend little on it,depending mostly on foreign donors. Donors areincreasingly worried about the environmentaleffect of the large amounts of chemicalpesticides used on locust control, and arepushing for more benign alternatives. Theresults of the present survey indicate thatthere may be a potential market for abiopesticide against grasshoppers and locustson cash crops in the humid areas. The potentialmarket in the Sahel depends on a reduction ofcosts or a subsidy of its price. This subsidycould be justified by the expected reduction inenvironmental and health costs when replacingchemical pesticides. Since donors are thecurrent purchasers of chemical pesticides forthe Sahel, they would also be expected to beinvolved in the purchase of the biologicalproduct. Copyright Kluwer Academic Publishers 2001