Xiao-Feng Xue

The brown planthopper, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), is an important pest of rice. To better understand the migration pattern and population structure of the Chinese populations of N. lugens , we developed and characterized 12 polymorphic microsatellites from the expressed sequence tags database of N. lugens . The occurrence of these simple sequence repeats was assessed in three populations collected from three provinces of China. The number of alleles per locus ranged from 3 to 13 with an average of 6.5 alleles per locus. The mean observed heterozygosity of the three populations ranged from 0.051 to 0.772 and the expected heterozygosity ranged from 0.074 to 0.766. The sequences of the 12 markers were highly variable. The polymorphism information content of the 12 markers was high and ranged from0.074 to 0.807 (mean = 0.503). Sequencing of microsatellite alleles revealed that the fragment length differences were mainly due to the variation of the repeat motif. Significant genetic differentiation was detected among the three N. lugens populations as the F st ranged from 0.034 to 0.273. Principle coordinates analysis also revealed significant genetic differentiation between populations of different years. We conclude that these microsatellite markers will be a powerful tools to study the migration routine of the N. lugens .

Four new species of the Diptilomiopinae (Acari: Eriophyoidea: Diptilomiopidae) from China are described and illustrated. They are Diptilomiopus vitisis n. sp. on Vitis sp. (Vitaceae), Diptacus chizhouensis n. sp. on Rubus corchorifolius Linn. f. (Rosaceae), Diptacus platycaryae n. sp. on Platycarya strobilacea Sieb. et Zucc. (Juglandaceae) and Apodiptacus albae n. sp. on Swida alba Opiz (Cornaceae). Diptacus gigantorubra Xin and Dong on Rubus pentagonus Wall. ex Focke (Rosaceae) is re-described. All the eriophyoid mite species described in the paper are vagrants on the undersurface of leaves, causing no apparent damage to the host plant.