Biological control of grasshopper population using dominant natural enemies in typical grassland of Yanchi in Ningxia

The types and dominant species of grasshoppers and natural enemies were investigated in the typical grassland of Yanchi in Ningxia with the systematic monitoring from 2010 to 2012. The relationship between grasshoppers and natural enemies was studied with canonical correlation analysis and the predatory function of Pterostichus gebleri to Chorthippus albonemus adults, and the dominant species of grasshopper, was tested in laboratory. The results showed that P.gebleri and Pseudotaphoxenus mongolicus, grasshoppers’ dominant natural enemies, had very important effects on the fluctuation of locusts sub-communities.P.gebleri was able to control the mixed populations of grassland locusts to a certain degree. The disc equation Holling-Ⅱ, Na=1.249 5N/(1+0.119 0N), was found to describe the functional response of P.gebleri to Chorthippus albonemus. The amount of predation increased with increasing prey C.albonemus density, with daily maximum capacity of 10 preys. Pterostichus gebleri can be used as important natural enemy in the biological control of grasshoppers.