Acoustic detection of insect pests of stored grains in Kenya

Grain production by Kenyan farmers, an important resource for their food security, faces constant challenges from pre- and post-harvest conditions favorable to rapid growth of insect populations. Currently, Kenya must import grain to meet consumption needs; however, if losses due to insects in storage facilities could be reduced, significant reductions in grain imports could be achieved. A review of current grain resources available in Kenya indicated that its grain production has increased over the last decade, but storage capacity has remained constant, with continued losses of up to 20-30% due to inadequate control of postharvest insect pests. Early warning of pest infestations can help managers reduce postharvest losses by enabling them to target and eliminate infestations before they increase to economically damaging levels. Because acoustic methods have been successfully used previously for early detection of infestations, an acoustic survey was done in selected maize grain stores in storage facilities in five Kenyan counties, Nairobi, Nakuru, Nyeri, Kirinyaga and Kiambu. Stores visited during the survey exhibited significant presence of Sitophilus zeamais Motschulsky, Prostephanus truncatus Horn and Tribolium castaneum Herbst. It was demonstrated that the use of acoustic technology canhelp managers identify and target infestations within their warehouses, enabling them to reduce postharvest losses.