Bionomics of Cenopalpus irani, Bryobia rubrioculus and their egg predator Zetzellia mali (Acari: Tenuipalpidae, Tetranychidae, Stigmaeidae) in natural conditions

Abstract : Bionomics of Cenopalpus irani Dosse and Bryobia rubrioculus Scheuten and their egg predator Zetzellia mali (Ewing) was studied in Kermanshah (west of Iran) from 31st May till 7th November 2007 on apple leaves and interaction (density dependence) between phytophagous mites and their predator were determined. The reliable sample size (number of leaves) with maximum variation of 5.33% was about 130. Index of dispersion, regression models (Taylor and Iwao), Morisita?s index and Lloyd?s mean crowding to mean were used to estimate spatial distribution pattern of these mites. The results indicated that the highest population density of C. irani, B. rubrioculus and Z. mali was in 19th August (13.45 per leaf), 9th August (0.615 per leaf) and 9th August (1.161 per leaf), respectively. Index of dispersion, regression models (Taylor and Iwao), Morisita?s index and Lloyd?s mean crowding to mean showed an aggregated distribution for all species. The linear regression between predator and preys population densities showed a density-dependant predation by Z. mali on C. irani and B. rubrioculus. Spatial distribution parameters of tetranychoid mites and their predator can be used to outline a sampling program, estimate population density of these mites and efficiency of the predator for using in orchards IPM
Keyword : Bryobia rubrioculus, Zetzellia mali, Cenopalpus irani, population density, spatial distribution, density dependence interaction, optimum sample size
Author(s) : , M. Darbemamieh, K. Kamali, Y. Fathipour
Downloads : 1820


Download View 2009 Vol. 4 Number 2