On The Species Diversity Of Syrphidae In The Districts Around Beijing-tianjin

This study was funded by Key Project of Basic Scientific and Technological Expert of the Ministry of Science and Technology of P. R. C., i.e. investigation of the natural enemy resources of insect in the districts around Beijing-Tianjin. The investigation of syrphids was carried out in the districts around Beijing-Tianjin where includes 6 provinces, 2 municipalities and 1 autonomous region(Beijing, Tianjin, Hebei, Henan, Shanxi, Heilongjiang, Liaoning, Jilin, Inner Mongolia). 3753 Syrphidae specimens were collected and 153 species(1 species undefined), 55 genera, 12 tribes, 3 subfamilies were recognized, including 59 species, 23 genera, 7 tribes of Eristalinae, 1 species of Microdontinae and 93 species, 31 genera, 4 tribes of subfamily Syrphinae. Two species are described new to sience: Allograpta borealis sp. nov., Chrysotoxum flavabdominis sp. nov.. one species, Spilomyia manicata(Rondani, 1865), is recorded from China for the first time, and 8 species are firstly recorded from Beijing, 4 species from Tianjin, 7 species from Hebei, 6 species from Liaoning, 7 species from Hebei, 1 species from Jilin, 7 species from Heilongjiang, 66 species from Shanxi, 10 species from Inner Mongolia. The male of Spilomyia bidentica, the female of Rhingia bimaculat and the female of Chrysotoxum liupanshanensis were founded and describedAfter the study of the species diversity of Syrphidae in nine different regions according to Administration district separately. Episyrphus balteatus was the dominant species of Syrphidae in the districts around Beijing-Tianjin. The highest species richness index is in Shanxi province(13.3574). The highest species diversity index is in shanxi province(3.5970) and The highest everness index of syrphids is in Shanxi(0.9520). The evenness index of syrphids inTianjin is the highest(0.9041). The results showed that the species of syrphids in Shanxi were rich, complex and the proportion of dominant species were the largest and the species of syrphids in Tianjin were evenly distributed.The faunal analysis of Syrphidae of the districts showed that Palaearctic region and Oriental region were predominant(68.42%), and elements of Palaeretic species(26.32%) were more abundant than that of Oriental species(5.26%). According to the distributional types, the mutli-zoogeographical genera are predominant(60%). The proportion of single-zoogeographic-al genera is the lowest(7.27%).