PS 34-159 - Population genetic analyses of massively emerging populations of the burrowing mayfly Ephemera orientalis (Ephemeroptera: Ephemeridae) in South Korea

Background/Question/Methods

Mayflies are one of the most ecologically important insects constituting aquatic ecosystems as they play diverse roles (as consumer and prey) in freshwater communities. A burrowing mayfly, Ephemera orientalis McLachlan (Ephemeroptera: Ephemeridae), widely distributed across the Korean streams, has recently become nuisance aquatic insects due to repeated local mass emergences in urban areas from spring to late summer. Despite its ecological and environmental significance in the aquatic ecosystems, population genetic aspects of E. orientalis remain poorly understood in South Korea and genetic features for the emerging patterns of the nuisance populations have not been investigated. In the current study, we developed novel polymorphic microsatellite markers for E. orientalis using a next generation sequencing (NGS). Population genetic structures and the level of genetic diversity of a total of 12 populations across South Korea including massively emerging populations were analyzed by the developed microsatellite markers.

Results/Conclusions

Mass emerging E. orientalis populations showed a higher level of genetic diversity compared to other populations, indicating their larger effective population size (N_e). A majority of massively emerging populations was found in the Han River, which is one of the major river systems in Korea, where urban areas are located nearby. Only two distinct genetic clusters with siginificant genetic differentiation were identfied by STRUCTURE analysis. Genetic differentiation between populations irrespective of grouping could explain most of genetic variances observed. Information on the level of genetic diversity and genetic structure of the Korean E. orientalis populations will be useful to understand the level of interpopulation differentiation, N_e, gene flow between populations and origin of mass emerging populations of E. orientalis. Ten novel microsatellite markers developed in the present study would further contribute to genetically monitoring the spatio-temporal patterns of population dynamics of E. orientalis.