Population genetic structure of Dioryctria abietella (Lepidoptera: Pyralidae) in Korea assessed using newly developed
Ji Hwan Han1, Seon Woo Bang1, Min-Woo Lee1
1Department of Agriculture, Forestry, and Bioresources, College of Agriculture and Life Sciences, Seoul National University , 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea.
Abstract:
Dioryctria abietella Denis & Schiffermüller (Lepidoptera: Pyralidae) is an oligophagous forest pest causing substantial ecological and economic damage to coniferous trees in Korea, yet its population genetic structure remains poorly understood. Here, we analyzed genetic diversity, population structure, and gene flow in 153 adult males from seven populations across South Korea using ten newly developed EST-SSR markers. All loci showed clear amplification, high polymorphism, and no linkage disequilibrium, confirming their suitability for population genetic analyses. Genetic diversity was generally high, although some locus-population combinations deviated from the Hardy-Weinberg equilibrium. Population genetic analyses revealed significant geographic structuring, with STRUCTURE, principal coordinate analysis, and UPGMA consistently identifying two major clusters: a northern-central mainland cluster and a distinct southern cluster including Gwangju and Jeju Island. A significant isolation-by-distance pattern indicated predominantly localized, short-range dispersal. Jeju Island population exhibited the strongest genetic differentiation and minimal gene flow, consistent with an oceanic barrier, whereas the Gwangju population showed moderate differentiation associated with historical founder effects rather than ongoing connectivity. In contrast, the Chungju population displayed high allelic richness, strong directional gene flow, and a modest heterozygote deficit, consistent with a weak Wahlund effect caused by admixture. AMOVA detected significant host-associated differentiation, however, the host plant explained only a small proportion of genetic variance, indicating a stronger influence of geography. Overall, these results demonstrate that spatial isolation and regional connectivity primarily shape D. abietella populations in Korea, providing a genetic basis for region-specific pheromone-based monitoring and management strategies.
