The white-backed planthopper, Sogatella furcifera (Horváth) (Hemiptera, Delphacidae), has emerged as a serious rice pest in Asia. In the present study, 12 microsatellite markers were employed to investigate the genetic structure, diversity and migration route of 43 populations sampled from seven Asian countries (Bangladesh, China, Korea, Laos, Nepal, Thailand, and Vietnam). According to the isolation by distance analysis, a significant positive correlation was observed between genetic and geographic distances by the Mantel test (r2 = 0.4585, P = 0.01), indicating the role of geographic isolation in the genetic structure of S. furcifera. A population assignment test using the first-generation migrants detection method (thresholds a = 0.01) revealed southern China and northern Vietnam as the main sources of S. furcifera in Korea. Nepal and Bangladesh might be additional potential sources via interconnection with Vietnam populations. This paper provides useful data for the migration route and origin of S. furcifera in Korea and will contribute to planthopper resistance management.

For a better understanding of the population structure and dispersal rates of Sogatella furcifera, we developed 21 novel polymorphic expressed sequence tags (EST) derived microsatellites, which were successfully amplified in four multiplex polymerase chain reaction sets. These new microsatellites were firstly assessed in 20 individuals sampled from Wenshan in China. The results showed that all 21 loci were highly polymorphic; the number of alleles ranged from 3 to 9, with an average of 4.8 alleles per locus. The observed and expected heterozygosity ranged from 0.200 to 0.900 and from 0.184 to 0.799, respectively. Nineteen of the 21 microsatellites without null allele, were subsequently used for population genetic structure analyses of five S. furcifera populations sampled in south region of China (sites up to 1314 kilometers apart). The observed and expected heterozygosity for each population ranged from 0.436 to 0.494 and from 0.454 to 0.482, respectively. The level of population differentiation was very low, with an average pairwise FST of 0.002. Bayesian cluster analysis result suggested that the five S. furcifera populations formed one genetic cluster. Discriminant analysis of principle components detected three genetic clusters. The spread of the three clusters across the five populations explained the lack of population differentiation and the Bayesian cluster result. All the results indicated that long-distance migration of this pest allowed genetic mixing between populations from remote geographical origins. These new microsatellites will be powerful tools for population genetics studies of S. furcifera.

The brown planthoppers (BPH) Nilaparvata lugens (Stål) and the white-backed planthoppers (WBPH) Sogatella furcifera (Horváth) annually migrate from tropical and subtropical regions to temperate regions in Asia, including Japan, Korea and northern China. To elucidate the genetic divergence based on geography of planthoppers and to estimate their migration route on the basis of molecular data, we analysed a part of their mitochondrial genome sequences. Sequences of cytochrome oxidase subunit I (cox1) – transfer RNA for Leu (trnL2) – cox2 were determined for 579 BPH (1,928 bp) and 464 WBPH (1,927 bp) individuals collected from 31 and 25 locations, respectively, in East and Southeast Asia. Thirty and 20 mitochondrial haplotypes were detected for BPH and WBPH, respectively. Single populations of both planthoppers included multiple haplotypes, and many haplotypes were shared in some populations and areas. The most frequently detected haplotypes accounted for approximately 50% of all BPH and WBPH individuals. To evaluate gene flow among planthoppers in different regions in Asia, pairwise fixation index (Fst) values were calculated. For BPH, high Fst values (0.580–0.926) were shown between planthoppers in Papua New Guinea (PNG) and the other areas and moderate Fst values (0.176–0.362) were observed between those in southern Philippines and other areas. For WBPH, the Fst value was the highest between Taiwan and southern Vietnam (0.236), and low among the other areas. AMOVA indicated no genetic structure among eight areas, excluding southern Philippines and PNG, for BPH, and among ten areas for WBPH. These data indicate that both planthoppers do not show much differentiation of local populations and/or have genetically intermixed Asian populations. These data also indicate that it may be difficult to distinguish regional planthopper populations on the basis of differences in mitochondrial sequences.

The banding patterns of six soluble enzymes of a Sogatella furcifera Horvath population from Sri Lanka, maintained in glass-houses on rice variety TN 1 at University of Wales, Cardiff, were studied. Crude homogenates of macropterous adults of both sexes were analysed, using polyacrylamide electrophoresis. The following enzymes showed activity and were stained: esterase (EST), lactate dehydrogenase (LDH), phosphoglucomutase (PGM), hexokinase (HK), glucose-6-phosphate dehydrogenase (G-6-PDH) and malic enzyme (ME). Number and relative mobility of bands varied between enzyme systems.

This selected bibliography on the whitebacked planthopper, Sogatella furcifera (Horváth), contains 506 published and unpublished references for the period 1899 to February 1984. References are arranged alphabetically by the name of the author and also classified by subjects. A distribution map, two tables of the varietal resistance to the pest and its natural enemies, and a brief description of the current status of the pest are also provided.