Host-associated genetic analysis of Thrips hawaiiensis (Thysanoptera: Thripidae), inferred from mitochondrial and microsatellite data

Thrips hawaiiensis (Morgan, 1913) (Thysanoptera, Thripidae), a frequent pest in crops and horticultural plants, is widely distributed in China. However, the population evolutionary history and genetic variability of T. hawaiiensis is unknown. In the current study, the genetic diversity and structure of T. hawaiiensis from thirteen host plants in two regions were detected using mitochondrial cytochrome oxidase subunit I (COI) gene and six microsatellite loci. From 123 individuals collected from thirteen flowering hosts, 23 haplotypes were identified, and the high genetic diversity of T. hawaiiensis was demonstrated by COI sequence and microsatellite data. Haplotype analysis indicated two clusters of T. hawaiiensis populations, Bayesian clustering analysis and PCoA analysis also supported this result. The genetic differentiation coefficient (F_st) and gene flow (Nm) showed weak gene differentiation and relatively high gene flow in T. hawaiiensis from different hosts. This might be facilitated through human activities, especially CL and GYZYMRJ with the closest geographical distance. The results of demographic analysis suggested that the differences in genetic structure of T. hawaiiensis from different host plants are not obvious, and genetic changes may be related to pesticide stres. The possible influences of T. hawaiiensis invasion history and human activities on the current haplotype host distribution were interpreted.