[Objective] The aim was to explore the species diversity of flower-visiting Syrphidae in the farmland of Hanzhong area.[Method] Based on the sample collection and the sorting and identification of collected specimens and literature,the species and their seasonal changes of flower-visiting Syrphidae in the agroecosystem of Hanzhong area were systematically analyzed.[Result] 5 015 specimens of Syrphidae were cheaked in this study,and 141 species of 53 genera of 16 families in three subfamilies of flower-visiting species of Syrphidae were identified in farmland of Hanzhong area,in which 65 species were Syrphinae;72 species were Milesiinae;while four species were Microdontinae.The species of Syrphidae in this region were active in April,May,June and July.There were two dominant species in this region,including Episyrphus balteatus and Eristalis tenax.[Conclusion] This study had provided theoretical basis for the studies on the flower-visiting habit and fecundation of insects of Syrphidae in this area.
[Objective] The paper was to study the flower-visiting habitus of three common syrphids in farmland of Hanzhong area in early spring.[Method] The active flower-visiting syrphids in farmland of hanzhong area in early spring was investigated,the annual activity rhythm,flower-visiting behavior,characteristics of mouthparts and their flower-visiting adaptability of three common syrphids were studied.[Result] About 20 species of active flower-visiting syrphids were found in farmland of hanzhong area in early spring,Eristalis tenax （Linnaeus,1758）,Episyrphus balteatus （De Geer,1776） and Eristalis cerealis Fabricius,1805 were predominant species in farmland.These three species could be found in farmland of Hanzhong area almost throughout the year,and they mainly activated on the flowers of rape and composites on the ridge of field in early spring.The activities of these flower-visiting syrphids were important to pollination of rape.The syrphid mouthparts had no structural characters in adaptation to flower-visiting,but the mouthparts were shorter,which was adaptive to visit the flowers with open and shallower corolla.[Conclusion] The results provided theoretical basis for further study on flower-visiting habitus and pollination effect of syrphids.
We describe a new species in the genus Didea Macquart from China： Didea zhongtiaoshanensis sp.nov. The new species is similar to Didea fasciata Macquart, but differs from the latter by tergite 5 and abdominal sternites. Type specimens are deposited in the Museum of Animals and Botany, Shaanxi University of Technology. A key to Chinese species in the genus Didea is offered.
