The three-band garden slug Ambigolimax valentianus, native to the Iberian Peninsula, is an exotic species distributed worldwide and was introduced to Japan into the 1950s. For control of this slug, it is necessary to elucidate its introduction sources and dispersal patterns since the introduction event occurred. However, knowledge about this slug in Japan remains poor. Thus, we attempted to estimate the origin and dispersal patterns of this slug using genetic approaches. We investigated the genetic diversity of the mitochondrial cytochrome c oxidase subunit I gene across 11 populations of A. valentianus in three prefectures in central Japan. Ten haplotypes were found in the Japanese populations, five of which were haplotypes found in foreign individuals. The same haplotypes were found in all three prefectures, whereas the average haplotype diversity was high across all populations. Significant genetic differentiation was detected among 22 of 55 population pairs, but there was no isolation by distance. These molecular results suggest that multiple introductions to Japan may have occurred in the past such that the founder effect in the early stage of introduction was diluted. Furthermore, long-distance dispersal of A. valentianus would have occurred after introduction into Japan because of human activities rather than natural dispersal.

三带花园garden Ambigolimax valentianus原产于伊比利亚半岛，是一种分布于世界各地的外来物种，于1950年代引入日本。为了控制该团块，自引入事件发生以来，有必要阐明其引入源和扩散方式。但是，关于这种this虫在日本的知识仍然很少。因此，我们试图使用遗传学方法来估计这种的起源和传播方式。我们调查了11个瓦克拟南芥种群中线粒体细胞色素C氧化酶亚基I基因的遗传多样性。在日本中部的三个县。在日本人口中发现了十种单倍型，其中五种是在外国个体中发现的单倍型。在所有三个县发现相同的单倍型，而在所有人群中平均单倍型多样性很高。在55个种群对中的22个中检测到显着的遗传分化，但没有通过距离进行隔离。这些分子结果表明，过去可能已经多次引入日本，从而削弱了引进初期的创始人效应。此外，引入日本后，由于人类活动而非自然扩散，会发生长距离传播A. valentianus。