Comparison of full mitochondrial genomes for the rice weevil, Sitophilus oryzae and the maize weevil, Sitophilus zeamais (Coleoptera: Curculionidae)

Complete mitochondrial genome sequences were assembled for the rice weevil, Sitophilus oryzae (17,602 bp) and the maize weevil, S. zeamais (18,105 bp; Coleoptera: Curculionidae: Dryophthorinae), which encode 13 protein coding genes (PCGs), 22 transfer RNAs, and 2 ribosomal RNAs that is typical among Animalia. The A + T-rich control regions of S. oryzae (2818 bp) and S. zeamais (2832 bp) are the longest described to date among curculionoidea (weevils). Additionally, non-coding intergenic regions have increased in size due to expansion of tandem repeat arrays, but is more pronounced in S. zeamais (606 bp) compared to S. oryzae (109 bp). A total of 69 and 22 substitution mutations were found among reads from S. oryzae and S. zeamais, out of which 68 and 2 were predicted in the PCGs respectively, with a majority in NADH Dehydrogenase subunit I. Phylogenetic analyses of coleopteran insects based upon full mitogenomes PCG sequence supported the existence of Curculionoidea and Tenebrionoidea as a monophyletic group, whereas the Cucujoidea and Elateroidea remain paraphyletic. The mitogenomes of these two Sitophilus species provide insight into short-term evolutionary relationships among curculionid beetles, and provide resources for the potential deciphering of more broad systematic questions in the Order Coleoptera.