Acoustic, pitfall trap, and visual surveys of stored product insect pests in Kenyan warehouses

Authors: NJOROGE, A - Purdue University; AFFOGNON, H - Institut Senegalais De Recherches Agricoles; RICHTER, U - University Of Kassel; HENSEL, O - University Of Kassel; ROHDE, B - University Of Florida; CHEN - University Of Florida; Mankin, Richard

Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/8/2019
Publication Date: 4/12/2019
Citation: Njoroge, A.W., Affognon, H., Richter, U., Hensel, O., Rohde, B., Chen, Mankin, R.W. 2019. Acoustic, pitfall trap, and visual surveys of stored product insect pests in Kenyan warehouses. Insects. 10(4):1-12. https://doi.org/10.3390/insects10040105.
DOI: https://doi.org/10.3390/insects10040105

Interpretive Summary: Grain storage pests cause $4 billion annually in losses in subsaharan Africa. Scientists at Purdue University, University of Florida, Conseil Quest et Centre Africain pour la Recherche et le Développement Agricoles, Dakar, Senegal, and at the USDA/ARS, Center for Medical, Agricultural and Veterinary Entomology in Gainesville, Florida, conducted acoustic, pitfall trap, and visual surveys of the population levels of the maize weevil larger grain borer, and red flour beetle in five warehouses in Kenya. The results demonstrate that acoustic technology is useful for targeting pest infestations in Kenyan warehouses, although precautions are necessary to avoid monitoring at times when background noise levels are too loud.

Technical Abstract: Grain production is an important component of food security in Kenya but due to environmental conditions that favor rapid growth of insect populations, farmers and other agricultural stakeholders face ongoing and novel challenges from crop and stored product pest insects. To assist development of methods to reduce economic losses from stored product insect pests in Kenya, acoustic, visual, and pitfall trap surveys were conducted in five grain storage warehouses. Two commercially available acoustic systems successfully detected the pests of greatest economic importance, Sitophilus zeamais (Motschulsky) and Prostephanus truncatus (Horn). Other insects of lesser economic importance also were observed in the visual surveys, including Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae), and Tribolium castaneum (Herbst). This study demonstrated that the use of acoustic technology with visual surveys and pitfall traps can help managers to identify and target infestations within their warehouses, enabling them to reduce postharvest losses. With most warehouses being located in relatively noisy urban or peri-urban areas, background noise considerations are being incorporated into the design of future acoustic detectors for stored pest infestations. Kenya must import grain yearly to meet consumption needs; however, if the current yearly postharvest losses of 20–30% in warehouses decreased, import costs could be reduced considerably.