Abstract: Objective  To investigate the bacteria diversity in larval gut of field-collected Anopheles sinensis.  Methods  The 16S rDNA V4 region of An. sinensis larvae collected from paddy on Jiading District of Shanghai （L1/L2）and small seeping water on Wenchang City of Hainan（AS） was sequenced by high-throughput pyrosequencing. Using Qiime and Mothur softwares, the number of sequences and operational taxonomic units（OTUs） for each sample was sorted and calculated, the species abundance and distribution, Alpha diversity index and difference times of species abundance among samples were analyzed.  Results  The number of sequences and OTUs for each sample were 253 724/3 930（L1）, 225 203/4 312 （L2） and 73 990/2 380 （AS）. The rarefaction curves showed that adequate sampling was achieved. The number of OTUs was close to actual situation. The value of richness index was 5 942.61/6 534.88（L1）, 6 328.17/7 235.89（L2） and 4 228.66/5 651.20 （AS）; diversity index was 4.63/0.03 （L1）, 5.10/0.02 （L2） and 0.14/3.94 （AS）. The dominant species of An. sinensis larvae gut microbiota all belonged to the phylum Proteobacteria, with a percentage of 87%（AS） and 90% （L）. In addition, the dominant phyla among them were Firmicutes, Bacteroidetes and Actinobacteria. The comparison of bacterial abundance between L and AS showed that there were 18 phyla with significant difference, except the Proteobacteria and Deinococcus-Thermus; only 9 phyla were different significantly between L1 and L2.  Conclusion  Evenness and richness of bacteria flora in the An. sinensis larvae gut collected from paddy and small seeping waters were obtained.

Key words: Anopheles sinensis, Larva, Bacterial flora, High-throughput sequencing