Assessing the economic impact of the desert locust infestation of 2019-2021 on Kenyan farmers and pastoralists using mobile phone interviews

Desert locusts are a major pest in agriculture, that can damage large areas of crop and pasture, inflicting high losses in a very short time. Most recently, a desert locust plague invaded East Africa In 2019-2020, the first time in some 50 years. Immediately, measures were taken to control the plague, mostly with chemical pesticides sprayed by plane. At the same time, no economic analysis is available to compare the losses caused by the locust and the losses abated through control, with the cost of these control measures. As the locust can strike suddenly over large areas and disappear for many years, it is difficult to obtain accurate data. This study takes advantage of new data collection methods, in particular mobile phones, to reach a random sample of farmer communities and individual pastoralists; these were first screened for the presence of, and damage caused by locust, in agricultural zones (121 communities), marginal (55) and pastoralist areas (146), interviewing 135. We found that few communities in agricultural areas are affected, and crop losses are relative minor, on average US$54 over the three seasons of the invasion. The were more substantial losses in pasture and grassland, although we were not able to valuate those losses, and, especially, in pastoralist areas. Most pastoralist communities, 64%, were affected and suffered livestock losses, reduced prices, reduce milk production and treatment of sick animals. We estimated the loss in cow and milk production at $192 million and the cost for treatment of animals who were affected by the locusts, at a total of $299 million the losses. We conclude that the locust invasion was a minor problem in agricultural areas, but a major problem in pastoralist areas. Mobile phones offer an excellent tool to assess the losses of locust in those areas, although sampling and estimation methods can be improved upon.