The soybean stem fly, Melanagromyza sojae, an Asian native insect, has successfully established in Brazil, Argentina, Paraguay and Bolivia. These countries are among the lead global soybean producing nations, being collectively known as the soybean belt of South America. Infestation levels of M. sojae grow by the year, facilitated by the lack of efficient management strategies. Previous studies have revealed a high number of maternal lineages in M. sojae populations from Southern Brazil and Paraguay, but a comprehensive survey on genetic diversity combining samples from all countries within the South American soybean belt remains absent. We used the mitochondrial DNA cytochrome oxidase I partial gene (mtCOI) to characterize specimens of M. sojae collected in fourteen Brazilian sites and one Argentine site, and then combined our mtCOI data with previously published data from Australia, Bolivia, Paraguay, and other Brazilian sites, to investigate genetic diversity in this invasive agricultural pest species. Based on the molecular characterisation of the mtCOI gene, haplotypes Msoj-COI-01 and Msoj-COI-02 have the highest frequencies in the continent. The high genetic diversity found is evidence of introductions involving multiple female founders into the continent, and the high proportion of unique mtDNA haplotypes identified from Brazil, Paraguay and Bolivia (~ 50%) suggests potential novel introductions have taken place. The findings from our study will contribute to a better understanding of M. sojae genetic diversity in South America, supporting the development of management strategies for this highly invasive pest and assisting with biosecurity preparedness of other emerging Agromyzidae flies of economic importance.

亚洲本地昆虫大豆茎蝇Melanagromyza sojae已在巴西，阿根廷，巴拉圭和玻利维亚成功建立。这些国家是全球大豆主产国之一，被统称为南美大豆带。由于缺乏有效的管理策略，大豆大豆的侵染水平逐年增加。先前的研究表明，来自巴西南部和巴拉圭的大豆分枝杆菌种群中有大量的母系，但是仍然缺乏对遗传多样性的综合调查，包括南美大豆带内所有国家的样本。我们使用线粒体DNA细胞色素氧化酶I部分基因（mtCOI）来表征大豆支原体在14个巴西站点和1个阿根廷站点收集了这些数据，然后将我们的mtCOI数据与澳大利亚，玻利维亚，巴拉圭和其他巴西站点以前发布的数据相结合，以调查这种入侵农业害虫物种的遗传多样性。根据mtCOI基因的分子特征，单倍型Msoj-COI-01和Msoj-COI-02在欧洲大陆具有最高的频率。发现的高遗传多样性是引进的证据，涉及多个女性创始人进入非洲大陆，从巴西，巴拉圭和玻利维亚鉴定出的独特的mtDNA单倍型比例很高（约50％），表明可能已经出现了新的引种。我们研究的结果将有助于更好地了解大豆 南美的遗传多样性，为这种高侵入性有害生物的管理战略的发展提供了支持，并协助其他具有经济重要性的新兴农杆菌科蝇的生物安全准备工作。