Abstract: 【Aim】 To investigate and analyze the changes in the structural composition, functional diversity and stability of terrestrial insect communities in different wetland types in Yinchuan, Northwest China. 【Methods】 Four wetland habitats including Yellow River wetland (HH), Mingcui Lake wetland (MCH), Luhuatai wetland (LHT) and Shuidonggou wetland (SDG) were selected based on the experimental design, and sampled from May to October, 2016. Insects were collected by chessboard sweeping and pitfall trapping approaches. Insect community structure diversity analysis, principal component analysis and cluster analysis were conducted based on the survey data. 【Results】 A total of 38 668 insects belonging to 370 species, 97 families and 13 orders were collected from the four wetland habitats in Yinchuan. Among them, Diptera, Homoptera, and Hymenoptera were the dominant groups in all the four habitats. Phytophagous insects accounted for the largest proportion in the family and species level of the insect communities among the four wetlands. The individual number showed a significantly negative correlation between the phytophagous and the neutral insects (Ph-Ne) in the four habitats (P<0.01). In the MCH habitat, the individual number showed a significantly positive correlation between the phytophagous and the predatory insects (Ph-Pr) (P<0.05), while a significantly negative correlation between the neutral and the predatory insects (Ne-Pr) (P<0.01). Additionally, in the LHT habitat, the individual number showed a significantly negative correlation between the neutral and the predatory insects (Ne-Pr) (P<0.05). Finally, the individual number in other combinations among the four functional groups did not show any significant correlation in all the four habitats. The predatory species group was the main component that affected the composition of the insect community based on principal component analysis (PCA). For the diversity analysis of the same functional group in the four habitats, there was a significant difference between the predatory (Pr) and the parasitic (Pa) functional groups based on the Simpson index (P<0.05), while there was no significant difference between the phytophagous (Ph) and the neutral (Ne) functional groups based on the Simpson index (P>0.05). Based on the Shannon-Wiener index, there was no significant difference among the neutral (Ne) functional groups in the four habitats (P>0.05), while there was a significant difference among the neutral (Ne) functional groups in the four habitats based on Pielou evenness index (P<0.05). Based on the Shannon-Wiener indices for the other three functional groups, there were significant differences among the four habitats (P<0.05), while they had no significant differences in the Pielou evenness index (P>0.05). The cluster analysis showed that the four types of wetlands were divided into two categories based on the characteristic index of insect communities, the first was permanent wetlands including HH and MCH, and the second was seasonal wetlands including LHT and SDG. Based on the stability index, the highest stability was found in the MCH habitat. The most stable periods for insect communities in different habitats were in May and September annually. 【Conclusion】 Diptera and Hymenoptera are the dominant groups in different wetland habitats in Yinchuan, and can be used as environmental indicators. The insect communities in the permanent lake wetland show the highest stability. The diversities of the insect communities in different habitats change with the seasons, and the most stable periods are in May and September annually. How the climatic factors and environmental factors drive the diversity to change and what factors affect the stability of insect communities in different wetlands remain to be studied.

Key words: Insect community, functional group, community diversity, community stability, wetlands