a Department of Genetics, University of Stellenbosch, Stellenbosch, South Africa.
b Department of Agricultural and Forestry Sciences, University of Palermo, Italy.
Genome. 2019 Mar;62(3):183-199. doi: 10.1139/gen-2018-0068. Epub 2018 Oct 26.
Wild and cultivated olives harbor and share a diversity of insects, some of which are considered agricultural pests, such as the olive fruit fly. The assemblage of olive-associated parasitoids and seed wasps is rich and specialized in sub-Saharan Africa, with native species possibly coevolving with their hosts. Although historical entomological surveys reported on the diversity of olive wasp species in the Western Cape Province of South Africa, no comprehensive study has been performed in the region in the molecular era. In this study, a dual approach combining morphological and DNA-based methods was used for the identification of adult specimens reared from olive fruits. Four species of Braconidae and six species of Chalcidoidea were identified, and DNA barcoding methodologies were used to investigate conspecificity among individuals, based on randomly selected representative specimens. Morphological identifications were congruent with DNA data, as NJ and ML trees correctly placed the sequences for each species either at the genus or species level, depending on the available taxa coverage, and genetic distances strongly supported conspecificity. No clear evidence of cryptic diversity was found. Overall seed infestation and parasitism rates were higher in wild olives compared to cultivated olives, and highest for and . These results can be used for early DNA-based detection of wasp larvae in olives and to further investigate the biology and ecology of these species.
野生橄榄和栽培橄榄都有丰富多样的昆虫栖息,其中一些被认为是农业害虫,如橄榄实蝇。在撒哈拉以南非洲,与橄榄相关的寄生蜂和种子蜂的集合是丰富而专门化的,可能与它们的宿主共同进化。尽管历史昆虫学调查报告了南非西开普省橄榄蜂物种的多样性,但在分子时代,该地区尚未进行全面研究。在这项研究中,采用了结合形态学和基于 DNA 的双重方法,用于鉴定从橄榄果实中饲养的成虫标本。鉴定出了四种 Braconidae 和六种 Chalcidoidea 物种,并使用 DNA 条形码方法,基于随机选择的代表性标本,调查个体间的同物异性。形态鉴定与 DNA 数据一致,NJ 和 ML 树正确地将每个物种的序列置于属或种水平,具体取决于可用的分类群覆盖范围,并且遗传距离强烈支持同物异性。没有发现明显的隐种多样性证据。与栽培橄榄相比,野生橄榄中的种子侵染和寄生率更高,其中 和 的最高。这些结果可用于基于 DNA 的早期检测橄榄中的黄蜂幼虫,并进一步研究这些物种的生物学和生态学。