seasonal activity of zetzellia mali (stigmaeidae) and its preys eotetranychus frosti (tetranychidae) and tydeus longisetosus (tydeidae) in unsprayed apple orchards of maragheh, northwestern of iran

seasonal activity and spatial distribution of eoteranychus frosti mcgregor, tydeus longisetosus (elbagouy and momen) and zetzellia mali ewing were studied during 9th july to 22th october 2006 in an unsprayed apple orchard, maragheh region, northwest of iran. also the density dependence interaction between preys and predator was assessed. to estimate the spatial distribution pattern of these species, data was analyzed through iwao's patchiness regression, taylor's power law, morisita's coefficient, lloyd's mean crowding and index of dispersion. iwao’s patchiness regressions and taylor’s power law showed a random and morisita’s coefficient, lloyd's mean crowding and index of dispersion revealed an aggregated distribution pattern for e. frosti, t. longisetosus and z. mali. the results indicated that the peak density of e. frosti and t. longisetosus occurred in mid september and in late august (2.46 and 4.4 per leaf, respectively). regarding their predator, the peak density (10.34) occurred in early july. the linear regression between prey and predator densities indicated a density independent predation by z. mali.