Population dynamics of stored maize insect pests in warehouses in two districts of Ghana

Authors: MANU, NAOMI - KWAME NKRUMAH UNIVERSITY OF SCIENCE AND TECHNOLOGY; OSEKRE, ENOCH - KWAME NKRUMAH UNIVERSITY OF SCIENCE AND TECHNOLOGY; OPIT, GEORGE - OKLAHOMA STATE UNIVERSITY; Campbell, James - Jim; ARTHUR, FRANKLIN; MBATA, GEORGE - FORT VALLEY STATE UNIVERSITY; Armstrong, Paul; DANSO, JAMES - KWAME NKRUMAH UNIVERSITY OF SCIENCE AND TECHNOLOGY

Submitted to: Journal of Stored Products Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/1/2018
Publication Date: 3/1/2018
Citation: Manu, N., Osekre, E.A., Opit, G.P., Campbell, J.F., Arthur, F.H., Mbata, G., Armstrong, P.R., Danso, J.K. 2018. Population dynamics of stored maize insect pests in warehouses in two districts of Ghana. Journal of Stored Products Research. 76:102-110. https://doi.org/10.1016/j.jspr.2018.01.001.
DOI: https://doi.org/10.1016/j.jspr.2018.01.001

Interpretive Summary: Understanding what insect species are present and where and when they are present is important for developing successful integrated pest management strategies for stored food. Corn is a staple food crop in many African countries and maintaining quality during storage is important to food security. Increasingly corn in Ghana is being stored in bags in warehouses, but little information is available on stored product insect activity in these warehouses. Using pheromone traps to monitor insect activity in and around warehouses in two regions in Ghana (Middle Belt and Northern Belt) it was shown that the most abundant species was the Indianmeal moth, but other major pest species such as red flour beetles, rice weevil and lesser grain borer were also recovered. Angoumous grain moth and larger grain borer, which are major pests on farms in Ghana, were more likely to be captured in traps outside or at nearby farms than inside the warehouses. Rice weevil was commonly captured in the warehouses, but was more abundant in the Middle Belt warehouse, than in the Northern Belt warehouses. Our results identified the major species found during warehouse storage of maize and suggest that the importance of specific pest species may be different in warehouses compared to on-farm storage. While temperature and humidity conditions were favorable for insect activity all year round, there was variation in captures in traps among sampling dates. This information provides an important baseline for the development of more targeted and effective pest management programs.

Technical Abstract: Understanding what insect species are present and their temporal and spatial patterns of distribution is important for developing a successful integrated pest management strategy for food storage in warehouses. Maize in many countries in Africa is stored in bags in warehouses, but little monitoring information is available on insect activity in these warehouses. Here we monitored the populations of major postharvest insect pests of maize at three different warehouses (MiDA, Gundaa and Wienco) in two regions in Ghana (Middle Belt and Northern Belt). The study was conducted from October 2015–July 2016, which represents a common maize harvest and storage period between the two regions. The most abundant insect pest found in the warehouses was Plodia interpunctella (Hübner), but other major pest species were recovered during the study. Sitotroga cerealella (Oliver) and Prostephanus truncatus (Horn) which are major pests on farms, were more likely to be captured in traps outside or at nearby farms than inside the warehouses. When recovered inside they tended to be found in the receiving and cleaning areas. Sitophilus zeamais (Motschulsky) was commonly captured in the warehouses, but was more abundant in the Middle Belt warehouse. Our results identified the major species found during warehouse storage of maize and suggest that the importance of specific pest species may be different in warehouses compared to on-farm storage.