Haplotype Analysis and Phylogeny of Oryzaephilus surinamensis Populations from Four Regions in Peninsular Malaysia

Abstract

The sawtoothed grain beetle, Oryzaephilus surinamensis, is a secondary pest that damages rice products and other stored grains. Analysis based on the cytochrome oxidase subunit I (COI) sequences data, the number of haplotypes (Hap) (n), haplotype diversity (Hd), haplotype network, genetic distance, and phylogeny between O. surinamensis populations from four regions (small-scale), viz. the northern area (Seberang Perai), middle area (Klang), southern area (Pasir Gudang), and east coast (Kuantan) of Peninsular Malaysia, as model sampling locations, were obtained. A total of five haplotypes were detected in all the test populations, two shared (Haplotype 1 and Haplotype 3) and three unique haplotypes (Haplotype 2, Haplotype 4, and Haplotype 5) with haplotype diversity value, Hd = 0.6789 were recorded. Furthermore, the neighbour-joining (NJ), maximum parsimony (MP), and Bayesian inference (BI) trees showed a mixture of individuals from all regions in Peninsular Malaysia (Haplotype 1 to Haplotype 4), except Haplotype 5, which was grouped with foreign populations that inherited similar haplotype with those of the European samples. This study assumed a mixture of populations presumably due to human activities and related explicitly to the exportation and importation of rice products across regions. This information is vital for strategising the control management of this pest species to reduce rice storage losses.