Joern Anthony, Rudd Nathan T
School of Life Sciences, University of Nebraska, 68588, Lincoln, Nebraska, USA.
Oecologia. 1982 Oct;55(1):42-46. doi: 10.1007/BF00386716.
The impact of predation by the robber fly Proctacanthus milbertii Macquart on populations of adult grasshoppers from grasslands of the Nebraska sandhills was estimated. Densities of P. milbertii were estimated at 437 individuals per hectare (2 se=122). Overall densities of 23 species of grasshoppers were estimated to be 64,000 individuals per hectare with the most abundant species (Ageneotettix deorum) having a population size of approximately 15,000 individuals per hectare. Based on three estimates of predation level (ranging from 0.5 to 2 prey per day per robber fly), P. milbertii may take from 0.5% to 2% of the adult grasshoppers per day. Species of grasshoppers were taken by P. milbertii in about the same proportion in which they occurred at the study site and no size-selective component of predation was detectable.
对盗虻（Proctacanthus milbertii Macquart）捕食内布拉斯加沙丘草原成年蝗虫种群的影响进行了估计。盗虻的密度估计为每公顷437只个体（标准误为122）。23种蝗虫的总体密度估计为每公顷64,000只个体，其中数量最多的物种（Ageneotettix deorum）种群规模约为每公顷15,000只个体。基于对捕食水平的三种估计（每只盗虻每天捕食0.5至2只猎物），盗虻每天可能捕食0.5%至2%的成年蝗虫。盗虻捕食的蝗虫种类比例与它们在研究地点出现的比例大致相同，且未检测到捕食的大小选择成分。
