We developed and characterized five polymorphic microsatellites of Nilaparvata lugens from hybridization method using biotin enrichment strategy and two polymorphic microsatellites from Next Generation Sequencing. Also 11 microsatellites that developed by Sun et al. (2011) are employed to carry out genetic analysis of N. lugens in Southeast Asia. The number of alleles per locus ranged from 2 to 12 with an average of 4.63 alleles per locus. The mean observed heterozygosity of the eleven populations ranged from 0.031 to 0.938 and the expected hetetrozygosity ranged from 0.031 to 0.881. Signifiant genetic differentiation was detected among the three N. lugens populations as the FST ranged from 0.028 (Cheong Do and Ha Long) to 0.161 (CH and BN). The results of microsatellite marker suggested that found N. lugens migrated to Korea at least two times in different period or once. Genetic distance of N. lugens between Korea and Hi Pong were mostly closed and genetic distance of Ha Long and HCM were relatively closed. In this study, development of microsatellites should facilitate the study of future population genetics of N. lugens, and eventually elucidate the route of N. lugens migration to Korea. Thus, combining satisfactory microsatellite markers and intensive surveillance methods in paddy field could be easy to understand to the N. lugens migration mechanism.

The Laodelphax striatellus(SBPH) (Homoptera:Delphacidae) is a major rice insect pest in Asia. It brings the indirect damage by transmitting Rice Stripe Virus (RSV) and Rice Black-Streaked Dwarf Virus (RBSDV). Molecular markers for genetics studies will be very helpful for dynamics of SBPH and viruses. For surveying genetic variation among populations of SBPH by microsatellite analyses, we used an enrichment strategy to develop microsatellite markers from SBPH. Eight polymorphic microsatellite loci were selected to characterize genetic structuring of SBPH populations.

The Laodelphax striatellus(SBPH: Small Brown Plant Hopper) is known to be not overwintering in South Korea and migrate from China to Korea every year by now, but these days many evidence support the possibility of SBPH overwintering. These insects do considerable damage to the rice production in Korea. If they will come from China, identification of origin of migration is very important to make countermeasure against SBHP outbreak. So we want to know exact the route of long-distance migration of them. In this study, we have developed some microsatellite markers for basic population genetic analysis of SBPH. We will show the genetic characteristics of them

The Nilaparvata lugesn(BPH) and Laodelphax striatellus(SBPH) are major insect pests of rice in Korea. These BPHs migrate from China to Korea, but we have not exactly known about the route of long-distance migration of them. Molecular markers including microsatellite will be critical to asses gene flow in relation to geographical distance. In our work several microsatellite markers were developed for basic population genetic analysis of BPH and SBPH. Among each 21 microsatellite markers in BPH and SBPH, we could select 6 markers for BPH and 2 markers for SBPH as putative markers for analysis of population genetics. Others are further investigated for the possibility as markers. Development of polymorphic microsatellite loci are final stage of our work. But for good microsatellite markers to population genetics, we should do more experiments. Our work for development of microsatellites should facilitate the study of future population genetics of BPH and SBPH, and eventually elucidate the route of BPH and SBPH migration to Korea.