Abstract: 【Aim】 This study aims to investigate the microbe composition (actinomycetes, bacteria and fungi) and the diversity of bacteria in the infrabuccal pocket of the Japanese carpenter ant, Camponotus japonicus, so as to explore their potential functions in food utilization and population immunity. 【Methods】 The culturedependent method and HiSeq high-througput sequencing technique were combined to analyze the microbes in the infrabuccal pocket, digestive tract and cuticle of C. japonicus workers collected in Yangling, Shaanxi, northwestern China. 【Results】 Ten actinobacterial strains were isolated from the infrabuccal pocket of C. japonicus workers, among which five strains belong to Streptomyce with the average isolation frequencies of 73.3%-96.7%. Seven bacterial strains were isolated and four of them were Bacillus, and the average isolation frequencies of the strains N-B1 and N-B4 were both above 70%. Three fungal strains were isolated, and the isolation frequency of the dominant strain P-F1 (Wickerhamiella) was up to 96.7%. All strains isolated from the crop, midgut and cuticle could be found in the infrabuccal pocket, and the species number of the strains and the number of microbial colonies isolated from the infrabuccal pocket were higher than those isolated from the cuticle, crop and midgut. The results of HiSeq high-throughput sequencing showed that the dominant bacterial groups in the infrabuccal pocket mainly belong to Proteobacteria, Firmicutes and Actinobacteria, but in the crop and midgut the dominant bacterial groups belong to Proteobacteria and Firmicutes. The dominant genera with high abundance were more in the infrabuccal pockets and crops than in the midgut, and the bacterial composition in the midgut was relatively simple. The dominant genera in infrabuccal pocket included Fructobacillus, Bacterium, Pseudomonas, Acinetobacter and Sphingtomonas. The microbial abundance and diversity in the infrabuccal pocket were higher than those in the crop and midgut. 【Conclusion】 Actinomycetes, Bacillus, yeasts and other predominant microbes generally exist in the infrabuccal pocket of C. japonicus, and their abundance and diversity levels are significantly higher than those in the digestive tract (crop and midgut). The potential roles of these microorganisms in food utilization, nutrient digestion and population immunity of ants need to be further studied.

Key words: Camponotus japonicus, infrabuccal pocket, digestive tract, microbiological cultivation, HiSeq high-throughput sequencing