Mitochondrial DNA diversity and gene flow in Southeast Asian populations of the synchronously flashing firefly, Pteroptyx tener Olivier (Coleoptera: Lampyridae)

Populations of the iconic, synchronously flashing firefly, Pteroptyx tener (Coleoptera: Lampyridae), are increasingly being threatened by habitat destruction and land conversion activities in Malaysia. Concerns on how this may have impacted the species led us to undertake an analysis of P. tener genetic diversity here. We also investigated how P. tener arrived at its present distribution along the west coast of Peninsular Malaysia using maps of Pleistocene sea levels in Southeast Asia and information on its mitochondrial DNA haplotype distribution. We detected three genetically-distinct populations in Malaysia, one each on the east and west coasts of Peninsular Malaysia and the other in Sarawak/Borneo. We found strong support for a scenario where an ancestral P. tener population diverged to form the Sepetang and Selangor River firefly populations when it became disconnected from the Malacca River system as sea levels rose during the late Pleistocene. An introduction event subsequently occurred when the Selangor and Sepetang River populations contributed to the formation of the Linggi River population. Lastly, the admixture event leading to the founding of the Linggi River population most likely occurred when it was connected to the Malacca River system during periods of changing sea levels in the late Pleistocene.