Population fluctuation of Neoseiulus barkeri (Acari: Phytoseiidae) and its prey, Tetranychus urticae (Acari: Tetranychidae), in cucumber fields of Khorramabad, Iran

Population density and spatial distribution of Neoseiulus barkeri Hughes and its prey, Tetranychus urticae Koch, in cucumber fields of Sarab-e Chengaei region in west of the city of Khorramabad, Lorestan province, were studied in 2008-2009. The population densities of both species in the first year was higher than the second year. The population densities for T. urticae and N. barkeri reached their peaks in late July and late August 2008, respectively. In 2009, the population peaks for both species occurred in late August. The reaction of N. barkeri to different population densities of its prey, with linear regression, was described as density independent. It was also found that mated females of N. barkeri overwintered in soil. The Taylor's power law regression method was used for finding the spatial pattern of the predator and prey, which was aggregated for both species. The correlation between the population fluctuation and spatial distribution pattern of the pest and its predator can effectively help to improve the strategy for a successful IPM program