Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IEGEBA (CONICET-UBA), Buenos Aires, Argentina.
Laboratoire of Interactions Host-Parasites-Environment, Université de Perpignan, CNRS, IFREMER, Université de Montpellier, Perpignan, France.
PLoS One. 2018 Nov 21;13(11):e0206602. doi: 10.1371/journal.pone.0206602. eCollection 2018.
The little fire ant Wasmannia auropunctata, native to the Neotropics, has become a serious pest worldwide over the past 100 years. It was originally distributed from Mexico to northern Argentina and new evidence suggests a recent southern range expansion during the last 60 years reaching central Argentina. This supercolonial ant species has a polymorphic reproductive system. Some populations, mostly found in undisturbed natural environments, are characterised by a classical sexual haplodiploid reproductive system. In other populations, which mainly occur in human-modified habitats, diploid queens and haploid males are produced clonally while workers are produced sexually. Here we studied the association between the recent southern range expansion of W. auropunctata in relation to human activity and clonality. We carried out an extensive survey within the southern limit of the species' native distribution and characterised the type of habitat where populations were found. Moreover, we genetically determined the type of reproductive system in 35 populations by genotyping at 12 microsatellite loci a total of 191 reproductive individuals (i.e. queens and/or males). Clonality was the most common reproductive system, occurring in 31 out of 35 populations analysed. All the populations found in the recently colonised area in central Argentina were clonal and established in human-modified habitats, suggesting that clonality together with human activity might have facilitated the southwards expansion of W. auropunctata.
红火蚁 Wasmannia auropunctata，原产于新热带地区，在过去的 100 年中已成为全世界的严重害虫。它最初分布于从墨西哥北部到阿根廷北部，新的证据表明，在过去的 60 年中，它的分布范围最近向南扩展，到达阿根廷中部。这种超殖民地蚂蚁物种具有多态生殖系统。一些种群，主要分布在未受干扰的自然环境中，其特征是经典的有性单倍体生殖系统。而在其他种群中，主要出现在人类改造的栖息地中，二倍体蚁后和单倍体雄蚁通过克隆产生，而工蚁则通过有性生殖产生。在这里，我们研究了红火蚁在人类活动和克隆性方面的最近向南扩展的关联。我们在该物种原生分布的南部极限内进行了广泛的调查，并描述了发现种群的栖息地类型。此外，我们通过对 12 个微卫星基因座共 191 个繁殖个体（即蚁后和/或雄蚁）进行基因分型，确定了 35 个种群的生殖系统类型。克隆性是最常见的生殖系统，在分析的 35 个种群中的 31 个中出现。在阿根廷中部新殖民地区发现的所有种群都是克隆的，并且建立在人类改造的栖息地中，这表明克隆性和人类活动可能促进了红火蚁向南扩展。
