Abstract: From March to October 2009, a field survey was conducted on the darkling beetle community structure and related environmental factors in the desert grasslands with different vegetation cover and human disturbance intensity in Sidunzi of Yanchi, Ningxia, China. By using diversity index and canonical correspondence analysis (CCA), the relationships between the beetle community structure and related environmental factors were analyzed. A total of 5431 individuals were collected, belonging to 20 species and 10 genera. Blaps femoralis femoralis, Microdera kraatzi kraatzi, and Platyope mongolica were the dominant species, accounting for 47.30%, 39.90%, and 3.59% of the total, respectively. CCA explained 100% of the correlations between the beetle species and related environmental factors, suggesting that the occurrence of the beetle species had close relations to the changes of related environmental factors. Among the environmental factors, the Shannon diversity index of plant community (HP), plant biomass (BP), and soil water content (SW) affected the beetle species occurrence most. The occurrence frequency of Mantichorula semenowi, Anatolica amoenula, A. sternalis, and A. gravidula was negatively correlated with BP and plant coverage (CP), and that of B. gobiensis, Cyphogenia chinensis, Gonocephalum reticuluatum, and Crypticus rufipes was positively correlated with plant density (DP) and SW. The distribution of P. mongolica, M. kraatzi kraatzi, Scytosoma pygmaeum, and B. kiritshenkoi showed a positive correlation to HP, and that of Eumylada oberbergeri, B. femoralis femoralis, and B. davidea showed a positive correlation to BP and CP. There was a significant positive correlation (r=0.943, P=0.005) between the beetle activity density and SW. The CCA ordination showed that the darkling beetles had different demands for multidimensional ecological resources in desert and semi-desert ecosystems.

Key words: darkling beetles, biodiversity, environmental variables, CCA, desert grassland, Yellow Sea, shrimp, community structure, species diversity, environmental factor.