IITA
International Institute of Tropical Agriculture
Locust and Grasshopper Biological Control Poject
BP. 08-0932 Cotonou, Benin
tel. 229 35 05 53/35 01 88 fax 229 35 05 56
iita-benin@cgiar.org

Abstract
In a survey in three countries of West-Africa using participatory rural appraisal techniques, we assessed the possibility of replacing chemical pesticides used against locusts and grasshoppers by biological control, based on an indigenous pathogen fungus produced at IITA-Cotonou. Using structured group and individual interviews combined with field visits, farmers' perceptions on locust and grasshoppers as a crop pest were assessed, as well as their quantitative estimation of crop losses and willingness to pay for locust control. Farmers as well as plant protection officers generally perceived locusts and grasshoppers as important pests that cause a lot of damage The use of the fungus with an oil-formulation and ULV equipment was demonstrated, and the results discussed with farmers. Their impressions of biological control were favorable, and the expressed an interest in using the technology. Farmers' expressed willingness to pay for locust control is small, but not negligible. Although political pressure for locust control is strong, national governments spend little on it, depending mostly on foreign donors. The results of the survey indicate that a market for biopesticides against grasshoppers and locusts is emerging for cash crops in the humid areas. Moreover, the potential for a market in the Sahel exist, but it depends on a reduction of costs or a subsidy of its price. This subsidy could be justified by reduced environmental and health costs.

keywords: participatory rural appraisal, locusts, grasshoppers, biological control, West Africa

March 23, 1999
LUBILOSA Socioeconomic Working Paper Series No. 99/1

The locust plague of 1986-89, the first in many years, was the cause of serious concern and substantial donor activity. While 25.9 million hectares were sprayed with chemical pesticides at a cost of $275 million (US Congress 1990), dissatisfaction with the heavy and continuing use of chemical pesticides was growing (Louis Berger and Associates, 1991). A consortium of donors (including the governments of Canada, Switzerland, The Netherlands, Great Britain and initially also the United States), agreed to finance LUBILOSA (Lutte Biologique contre les Locustes et les Sauteriaux), a research program initiated in 1989. A network of collaborators from CABI Biosciences (formerly IIBC: International Institute of Biological Control), IITA (International Institute of Tropical Agriculture), CILLS (Comité Permanent Interetats de Lutte Contre la Secheresse) and GTZ (Deutsche Gesellschaft für Technische Zusammenarbeit) is implementing the program.

In the initial phase a biopesticide was developed based on the spores of a fungus, Metarhizium anisopliae var. acridum, a natural pathogen of locusts, virulent but highly specific. A pilot plant was developed for the production of large quantities of spores (Jenkins et al., 1996), and an oil-based application formulation was developed. In the second phase of the project (1993-1995) field trials were carried out on different locusts species in several African countries (Lomer, 1997), including those of the humid tropics of Benin (Douro-Kpindou et al. 1993) as well as the Sahelian species in Niger (Kooyman et al. 1997) and Mali (Shah et al. 1998). The results are promising, with mortality rates of 80% or higher, although this mortality is only reached after one to two weeks, and the product is easy to store and to apply. The developed biopesticide is technically clearly a powerful technology, but its economic viability has not yet been demonstrated.

Therefore, farmers' interest in this new technology needs to be assessed. More specifically, the benefits need to be compared to the costs, potential sociological constraints examined, and the interest of the political decision makers assessed, especially plant protection agencies and donors.

Farmers in different Sahelian countries generally consider locusts and grasshoppers as major pests (Stonehouse et al 1997), but its control is judged beyond the individual farmer's capacity. Farmers clearly want the government to take this responsibility, but no economic analysis is really available to justify such an intervention. A attempt to quantify crop losses due to different pests on a national scale was organized over three years in Niger (Krall, Youm and Kogo, 1995). The results indicated that locust and grasshoppers cause relatively small losses, and that their control is probably not economically justified. Another attempt, pooling existing data of the desert locust and making a fair number of assumptions to fill the blanks, comes to the tentative conclusion that desert locust control is only economical 10% of the years (Joffe 1997).

To shed more light on these conflicting views, a broad survey was organized consisting of interviews with farmers, extension officers, NGOs and officials in locust prone areas of Niger, Benin, and Mali. This survey was part of a participatory research effort by the LUBILOSA program. The present study elaborates on previous work and extends it to the humid zones, and includes farmers' ranking of crop pests, quantitative estimates of crop losses, farmers' interest in and willingness to pay for locust control, and their observations concerning the use biopesticides against locusts and grasshoppers.

The paper is organized as follows. First the methodology will be discussed, with a review of the concepts, the choice of region and villages, and the tools used. The results for the three different areas will then be discussed in three separate sections, followed by the conclusions and recommendations for further study.

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