Title: DISTRIBUTION OF AND ASSOCIATION BETWEEN THE LARGER GRAIN BORER PROSTEPHANUS TRUNCATUS (HORN) (COLEOPTERA: BOSTRICHIDAE) AND THE MAIZE WEEVIL SITOPHILUS ZEAMAIS MOTSCHULSKY (COLEOPTERA: CURCULIONIDAE) IN MAIZE STORES
Submitted to: Journal of Stored Products Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 2, 2004
Publication Date: July 1, 2005
Citation: Vowotar, K.A., Meikle, W.G., Ayertey, J.N., Markham, R. 2005. Distribution of and association between the larger grain borer prostephanus truncatus (horn) (coleoptera: bostrichidae) and the maize weevil sitophilus zeamais motschulsky (coleoptera: curculionidae) in maize stores. Journal of Stored Products Research.
Interpretive Summary: The larger grain borer and the maize weevil are the most important pests of stored food in West Africa, and together they often cause grain losses of 20% or more. Research is being conducted to understand how these insects invade the stored grain stores. Corn cobs were sampled once a month from different grain storage bins in Benin, West Africa, so that farmers can know when to begin protecting them from insect invasions. One insect pest was discovered to have already infested the corn prior to storage, while another entered later. This information can be used by farmers and extension agents to help decide when to apply prevention or control measures for pests, while saving money on treatment costs.
Interspecific interactions between the larger grain borer Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) and the maize weevil Sitophilus zeamais Motschulsky (Coleoptera Curculionidae) were studied during two storage seasons in maize stores, in Bénin. Maize ears, randomly sampled from farmers’ grain stores, were 'reared out', i.e. kept for 4 weeks under controlled conditions for F1 to emerge, and periodically sampled, in order to examine colonization patterns of P. truncatus and S. zeamais. For both storage seasons, P. truncatus and S. zeamais populations were sparsely aggregated and not associated with each other. The degree and strength of association increased with each sampling occasion with respect to the Ochiai, Jaccard and Dice indices of association. By the fourth sampling occasion, P. truncatus was found on most ears and on some ears in very high numbers (>300 insects). Almost all ears with P. truncatus contained at least a few S. zeamais individuals, but many ears with S. zeamais contained no P. truncatus.