Bio-Protection Research Centre, PO Box 84, Lincoln University, Lincoln 7647, Canterbury, New Zealand.
Mol Phylogenet Evol. 2012 Sep;64(3):428-40. doi: 10.1016/j.ympev.2012.04.018. Epub 2012 May 18.
Several species of sap beetles in the genus Carpophilus are minor pests of fresh produce and stored products, and are frequently intercepted in biosecurity operations. In the South Pacific region, the superficially similar species C. maculatus and C. oculatus are frequently encountered in these situations. Three subspecies of C. oculatus have been described, and the complex of these four taxa has led to inaccurate identification and questions regarding the validity of these taxa. A molecular phylogenetic study using the mitochondrial gene cytochrome c oxidase I (COI) and two nuclear markers comprising the rDNA internal transcribed spacer 2 (ITS2) and the D1-D2 region of the large (28S) ribosomal RNA subunit showed that C. maculatus, and C. o. cheesmani were easily differentiated from the two other subspecies of C. oculatus. COI also showed differentiation between C. o. gilloglyi and C. o. oculatus, but this was not shown when third codon positions were removed and when RY-coding analyses were conducted. Generalised mixed Yule-Coalescent (GMYC) models were fitted to trees estimated from the COI data and were analysed using a multimodel approach to consider the evidence for three taxonomic groupings of the C. oculatus group. While the arrangement with the highest cumulative weight was not the arrangement ultimately accepted, the accepted taxonomy also had an acceptable level of support. ITS2 showed structure within C. oculatus, however C. o. oculatus was resolved as paraphyletic with respect to C. o. gilloglyi. COI showed evidence of sequence saturation and did not adequately resolve higher relationships between species represented in the dataset. 28S resolved higher relationships, but did not perform well at the species level. This study supports the validity of C. maculatus as a separate species, and provides sufficient evidence to raise C. o. cheesmani to the level of species. This study also shows significant structure within and between C. o. gilloglyi and C. o. oculatus, giving an indication of recent speciation events occurring. To highlight the interesting biology between these two taxa, C. o. gilloglyi is retained as a subspecies of C. oculatus. These results give clarity regarding the taxonomic status of C. maculatus and the subspecies of C. oculatus and provide a platform for future systematic research on Carpophilus.
几种 Carphophilus 属的鳃金龟是新鲜农产品和储存产品的次要害虫，并且经常在生物安全作业中被截获。在南太平洋地区，形态相似的 C. maculatus 和 C. oculatus 经常在这种情况下出现。已经描述了 C. oculatus 的三个亚种，这四个分类群的复合体导致了不准确的鉴定，并对这些分类群的有效性提出了质疑。使用线粒体基因细胞色素 c 氧化酶 I (COI) 和两个核标记（包括 rDNA 内部转录间隔区 2 (ITS2) 和大 (28S) 核糖体 RNA 亚基的 D1-D2 区）进行的分子系统发育研究表明，C. maculatus 和 C. o. cheesmani 很容易与 C. oculatus 的另外两个亚种区分开来。COI 还显示了 C. o. gilloglyi 和 C. o. oculatus 之间的分化，但当删除第三个密码子位置并进行 RY 编码分析时，这种分化并不明显。广义混合 Yule-Coalescent (GMYC) 模型被拟合到从 COI 数据估计的树中，并使用多模型方法进行分析，以考虑 C. oculatus 组的三个分类群分组的证据。虽然累积权重最高的排列不是最终接受的排列，但接受的分类学也具有可接受的支持水平。ITS2 在 C. oculatus 中显示出结构，但 C. o. oculatus 相对于 C. o. gilloglyi 是并系的。COI 显示出序列饱和的证据，并且不能很好地解决数据集代表的种间的更高关系。28S 解决了更高的关系，但在物种水平上表现不佳。这项研究支持 C. maculatus 作为一个独立物种的有效性，并提供了足够的证据将 C. o. cheesmani 提升到物种水平。这项研究还显示了 C. o. gilloglyi 和 C. o. oculatus 内部和之间的显著结构，表明最近发生了物种形成事件。为了突出这两个分类群之间有趣的生物学，C. o. gilloglyi 被保留为 C. oculatus 的一个亚种。这些结果澄清了 C. maculatus 和 C. oculatus 亚种的分类地位，并为 Carphophilus 的未来系统研究提供了一个平台。
