Abstract: To understand the response of insects to excessive reclamation of natural wetlands, species richness and distribution of insect fauna were investigated in the Caizihu Wetland Nature Reserve, a changing subtropical wetland landscape in southern Anhui, east China by light trap and hand collection periodically from May to August of 2013. Species were recorded from the two traditional land-use types (cropland and intertidal-grass area), and from the recently established grass-shrub zone. A total of 7251 insect individuals belonging to 235 species, 207genera, 89 families and 8 orders were recorded. The dominant orders were Diptera, Hemiptera, and Orthoptera, accounting for 27.61%, 25.54% and 15.96% of total individuals, respectively. Species richness was the highest in the cropland, the lowest in the grass-shrub, and the intertidal-grass area showed an intermediate value. The diversity comparison among the three habitats based on Shannon index and ACE estimate value showed that there were no significant differences between grass-shrub and intertidal-grass area, and both of their richness indices were significantly lower than that of the cropland habitat (P<0.05). The mean value of similarity indexes of the three habitats was 0.25±0.02, showing both vegetation type and excessive reclamation had great impacts on the insect community diversity.

Key words: nitrogen level, wheat powdery mildew, intercropping, nitrogen accumulation and allocation