Relationship between grasshopper outbreak and plant community in typical grassland of Yanchi in Ningxia

The relationship between ecological distribution of grasshopper and environmental factors is theoretical basis to reveal geographic occurrence of grasshopper. The relationship between grasshopper population composition and vegetation community was studied using field investigation and quantitative analysis in typical steppe of Yanchi in Ningxia. The results showed that there were 24 different species of grasshoppers in typical steppe of Mahuangshan Mountain and the dominant species were Calliptamus barbarus, Oedaleus asiaticus, Angaracris rhodopa, Bryodema nigroptera, Bryodemella tuberculatum, C.abbreviates, Compsorhipis davidiana, Chort hippus dubius, C.albonemus. The numbers of individuals and richness and diversity of species had positive correlation with the diversity, biomass and coverage of vegetation and had negative correlation with the evenness and height of vegetation. The numbers of individuals, and richness and diversity of species had negative correlation with the dominance of the families of Gramineae and Compositae and had positive correlation with the dominance of the families of Leguminosae and others. O.asiaticus, A.rhodopa and C.albonemus performed best in terms of selectivity for grass forages and E.coerulipes and F.beicki performed best for composite forages based on the correlation between dominant species and vegetation community. C.albonemus, F.beicki and E.coerulipes preferred to the poor vegetation conditions, while A.rhodopa preferred to the good vegetation conditions.