Genetic Differentiation of the Bloodsucking Midge IForcipomyia taiwana/I : Implication of the Geographic Isolation by the Central Mountain Ranges in Taiwan

• Published in: Insects (Basel, Switzerland) Switzerland), 2024-01, Vol.15 (1)
• Main Authors: Ching, Yung-Hao, Kuo, Yuan-Chen, Su, Ming-Ching, Wang, Szu-Chieh, Lin, Chuen-Fu, Tu, Wu-Chun, Lin, Ming-Der
• Format: Article
• Language: English
• Subjects: Biological research; Biology, Experimental; Population genetics
• ISSN: 2075-4450; 2075-4450
• DOI: 10.3390/insects15010023

Our study elucidates a genetic differentiation of F. taiwana populations across the central mountain ranges of Taiwan, which stands out as a significant geographical feature shaping these populations’ genetic landscape. The mountain range acts as a significant topographic barrier, influencing gene flow and contributing to distinct genetic clusters in eastern and western regions. Despite potential mechanisms for passive dispersal, such as human-mediated transportation and monsoon winds, the genetic divergence remains pronounced. These findings provide crucial insights for understanding the species’ molecular ecology and can inform targeted pest management strategies. Future research, involving more detailed genomic analyses, will be pivotal in exploring specific genetic adaptations and further elucidating gene flow across these geographical divisions. Forcipomyia (Lasiohelea) taiwana, a small bloodsucking midge, thrives in moderately moist habitats and is commonly found in grassy and bushy areas at an elevation below 250 m. This species exhibits a diurnal biting pattern and shows a marked preference for human blood. Although not known to transmit arthropod-borne diseases, the bites of F. taiwana can induce severe allergic reactions in some individuals. As a significant nuisance in Taiwan, affecting both daily life and the tourism industry, comprehensive studies on its population genetics across different geographical regions remain scarce. The central mountain ranges in Taiwan, comprising more than two hundred peaks above 3000 m in elevation, extend from the north to the south of the island, creating distinct eastern and western geographical divisions. This study utilizes microsatellite markers to explore the genetic differentiation of F. taiwana populations located in the eastern and western regions of the mountain ranges. Our findings reveal substantial genetic differentiation among populations inhabiting Taiwan’s western region compared to those in the eastern region. This indicates that the topographical barriers presented by the mountain ranges significantly restrict gene flow, particularly given the species’ limited active flight ability and habitat preferences. Although passive dispersal mechanisms, like wind or human activity, could contribute, this study concludes that the gene flow of F. taiwana between the western and eastern regions is primarily influenced by topographical constraints.