Genetic differentiation of the pine processionary moth at the southern edge of its range: contrasting patterns between mitochondrial and nuclear markers

The pine processionary moth (Thaumetopoea pityocampa) is an important pest of coniferous forests at the southern edge of its range in Maghreb. Based on mitochondrial markers, a strong genetic differentiation was previously found in this species between western (pityocampa clade) and eastern Maghreb populations (ENA clade), with the contact zone between the clades located in Algeria. We focused on the moth range in Algeria, using both mitochondrial (a 648 bp fragment of the tRNA-cox2) and nuclear (11 microsatellite loci) markers. A further analysis using a shorter mtDNA fragment and the same microsatellite loci was carried out on a transect in the contact zone between the mitochondrial clades. Mitochondrial diversity showed a strong geographical structure and a well-defined contact zone between the two clades. In particular, in the pityocampa clade, two inner subclades were found whereas ENA did not show any further structure. Microsatellite analysis outlined a different pattern of diffe...松异舟蛾（Thaumetopoea pityocampa）是马格里布（Maghreb）地区其分布范围南缘针叶林的重要害虫。此前基于线粒体标记（mitochondrial markers）的研究表明，该物种的西部种群（pityocampa支系）与马格里布东部种群（ENA支系）之间存在显著遗传分化，两支系的接触带（contact zone）位于阿尔及利亚境内。本研究聚焦该蛾类在阿尔及利亚的分布范围，同时采用线粒体（mitochondrial）标记（tRNA-cox2基因的648 bp片段）与核基因（nuclear）标记（11个微卫星位点（microsatellite loci））开展分析。此外，针对线粒体支系间接触带的样带（transect）种群，我们采用更短的线粒体DNA（mtDNA）片段与同一套微卫星位点进行了进一步分析。结果显示，线粒体多样性呈现出强烈的地理结构，且两支系间存在清晰的接触带；具体而言，pityocampa支系内部可分为两个亚支系，而ENA支系未表现出进一步的遗传结构。微卫星分析则揭示了差异化的分化模式……