Effect of nitrogen content in Leymus chinensis and Stippa capillata on feeding choice of Oedaleus asiaticus

Two dominant plant species of Inner Mongolia grassland: Leymus chinensis and Stipa capillata were selected as materials to study the effects of N content change on O.asiaticus feeding selection. Food selection frequency and food intake amount of 5th instars stage larva and adult individuals of Oedaleus asiaticus were mensurated by means of artificial feeding on different herbage of unfertilized(ON) and fertilized(HN) forage. The results show that N content in food is not an important limiting factor in feeding selection and food intake amounts for O.asiaticus at 5th instars stage, but at adult stage, O. asiaticus, especially the male individuals are more interested in low N content plant or S. capillata. The results imply that the selective frequency and food intake amounts of O. asiaticus on L. chinensis and S. capillata at high or low N fertilization could be adjusted according to developmental stage, sex and N content in herbage. However, O. asiaticus tends to select low N content plant in the process of grasshopper evolution.