Genetic diversity and population genetic structure from different host populations of <em>Spodoptera litura</em> based on microsatellite markers

Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) is an agricultural pest with a wide distribution range and many host plants, which can cause serious economic losses. In this study, 157 samples were collected from 8 hosts (tobacco, soybean, taro, peanut, chili, sweet potatoes, corn, and sorrel) in Fuli Town, Fuchuan County, Hezhou City, Guangxi Zhuang Autonomous Region. Seven microsatellite loci were used to analyze the genetic diversity, genetic structure, and genetic differentiation of these populations. The results showed that the number of alleles (Na) of 8 populations ranged from 2.43 to 6.14, the average of polymorphism information content (PIC) was 0.4574, the mean of observed heterozygosity (HO) and expected heterozygosity (HE) were 0.4926 and 0.5693, respectively. The genetic diversity of different host populations was high. Based on the Bayesian clustering and NJ phylogenetic tree of genetic structure, it was shown that there were certain genetic structures among different host populations, which could be roughly divided into four genetic groups. The fixed coefficient (FST) between populations ranged from 0.010 to 0.208, with low to highly differentiated populations as a whole. This study is helpful to understand the occurrence regularity of Spodoptera litura from different host plants, and provides a theoretical basis for the reasonable adjustment of crop layout in the field and the establishment of a corresponding comprehensive control system.