Population Structure of the Asian corn borer, Ostrinia furnacalis (Lepidoptera: Crambidae) in China, Japan and Southeast Asia

The Asian corn borer, Ostrinia furnacalis (Guenée) is an important economic pest of corn production and is widely distributed throughout the Asia-Pacific region. Since previous population genetic studies on this species were limited to its northern distribution, the current study expanded sampling locations to Southeast Asia. The geographic distribution of mtDNA variation of O. furnacalis in China, Japan, Philippines, Vietnam, Malaysia and Indonesia were examined. Late instar larvae were collected from Philippines and Indonesia, while adults were obtained from Malaysia and China. The DNA was extracted separately from five to six individuals for each location. Mitochondrial cytochrome oxidase II genes were amplified and the 666 bp nucleotide sequences were determined. These sequences were aligned with nucleotide sequences that were previously deposited in the Genbank: O. furnacalis from Japan, China, Philippines and Vietnam, as well as O. nubilalis (Hübner) from various locations in United States and Europe. These alignments were analyzed by analysis of molecular variance. Phylogenetic relationship was examined using parsimony, maximum likelihood, and neighbor joining, while sequence divergence by distance matrix. Ostrinia furnacalis is clustered into two sister clades with a low bootstrap support (19%): (1) exclusively from China-Japan and (2) predominantly from Southeast Asia with some from China-Japan. Both O. furnacalis clades are similar (<1% differentiation) and show high similarity (<1.5% differentiation) to a closely related species, O. nubilalis. This study added new information on the population diversity and structure of O. furnacalis and will be advantageous to design better insect pest management strategy of this pest.