关键词: 鼠疫, 自然疫源地, 蚤类, 群落, 准噶尔盆地

Abstract: Objective To investigate the community structure of parasitic fleas on the main rodents in Junggar Basin plague focus, and to analyze the role of each flea species in plague epizootiology. Methods The community structure factors, similarity, and clustering of parasitic fleas on rats in Junggar Basin were determined by community ecology methods. Results The community structures of parasitic fleas on Rhombomys opimus, Meriones meridianus, and Meriones erythrourus were the most complex, with the highest community richness, diversity, and relative rare species number, but without significant dominance. The parasitic fleas on Dipus sagitta had the second most complex community, with a community richness of 8, a mean rare species richness of 12.39 (the highest), a relative rare species number of 50.00%, and a diversity of 1.4838. The communities of parasitic fleas on Meriones tamariscinus and Allactaga sibirica were relatively complicated, with moderate homogeneity and advantages (both between 0.5 and 0.6), and both of them showed a species richness of 5, accounting for 31.25% of all flea species in the focus. In addition, they had mean species richness of 1.38 and 8.65 and relative rare species numbers of 20.00% and 40.00%. The community structures of parasitic fleas on Allactaga elater, Cricetulus griseus, Mus musculus, and Apodemus sylvaticus were simple, all with a relative rare species number of 0 and a mean species richness below 1.00. A. sylvaticus had only 1 species of flea, and the parasitic fleas on A. elater, C. griseus, and M. musculus had community richness of 2-4. The mean value of similarity index between the parasitic fleas on Rh. opimus, M. meridianus, M. erythrourus, D. sagitta, A. elater, C. griseus, and A. sylvaticus and other rats was greater than 0.5, and the mean value of similarity index between the communities of parasitic fleas on M. tamariscinus, A. sibirica, and M. musculus and other rats was less than 0.5. The communities of parasitic fleas on M. meridianus and other rats showed the highest similarity, with a mean value of similarity index of 0.6836, and the similarity index between the communities of parasitic fleas on M. meridianus and 7 species of rats was greater than 0.6, followed by the parasitic fleas on Rh. opimus and D. sagitta, which demonstrated a similarity index greater than 0.5, as compared with those on 6 species of rats. The similarity index between the communities of parasitic fleas on A. sibirica and other rats was the lowest (all below 0.5). The parasitic fleas on M. musculus showed a similarity index greater than 0.5 only when compared with those on M. erythrourus and M. tamariscinus, and had a mean value of similarity index of 0.2812 when compared with the fleas on other rats. The communities of parasitic fleas on the 10 species of rats were clustered into 3 phylogenetic branches (the communities on Rh. opimus, M. tamariscinus, and M. erythrourus, the communities on M. meridianus, and the communities on D. sagitta, A. sibirica, A. elater, M. musculus, A. sylvaticus, and C. griseus). Conclusion The fleas on rodents in the Junggar Basin plague focus exist in complex ecological communities. The communities of fleas on Rh. opimus, M. meridianus, and M. erythrourus are dominant in maintaining the complexity and diversity of fleas, while the communities of fleas on A. elater, C. griseus, A. sylvaticus, and M. musculus are complementary. There is extensive exchange of fleas among the rats in this region, and the fleas on M. meridianus are a key factor for the exchange. Rh. opimus and its fleas play a key role in plague epizootiology in the focus, and M. meridianus and its fleas may promote the prevalence of animal plague.

Key words: Plague, Natural focus, Flea, Community, Junggar Basin