Development and characterization of novel microsatellite markers for Tribolium castaneum (Coleoptera: Tenebrionidae)

The red flour beetle, Tribolium castaneum (Herbst), is a major pest of stored products. Microsatellite markers offer valuable tools for population genetic studies; however, existing markers often exhibit limited polymorphism or lack validation in field-collected populations. In this study, microsatellite loci were identified from whole-genome sequencing data of T. castaneum and tested for their utility in Malaysian populations. A total of 13.8 million sequence reads yielded 108,318 primer pairs, from which 20 markers were selected for screening. Of these, 7 loci consistently amplified and exhibited high levels of polymorphism, producing 14 to 28 alleles per locus. Expected heterozygosity values ranged from 0.798 to 0.962, and polymorphic information content exceeded 0.750 for all loci, indicating their high informativeness. Population differentiation analysis revealed moderate genetic structuring among populations (mean FSt = 0.162), suggesting restricted gene flow across sampled regions. These results demonstrate that the newly developed microsatellite markers are robust and highly polymorphic, providing a valuable resource for population genetic studies of T. castaneum and supporting efforts to understand pest dispersal and management in Malaysia.