Effect of temperature on development and fecundity of the brown mite, Bryobia rubrioculus Scheuten (Acari: Tetranychidae) on apple

Brown mite, bryobia rubrioculus scheuten, is one of the most important pests of apple trees inwestern iran. development and fecundity of this mite were studied on apple at five constanttemperatures (20, 22.5, 25, 27.5 and 30°c), 60 ± 5% rh and a photoperiod of 16:8 h (l: d). thedevelopmental time of immature stages ranged from 39.65 ± 0.96 days at 20°c to 18.18 ± 0.47days at 30°c. the lower temperature threshold (t) and thermal constant (k) of the immature stageswere estimated to be 12.9°c and 279.7 degree days (dd), respectively. the average adultlongevity of females was determined to be 16.75 ± 1.14 days at 20°c to 8.58 ± 0.38 days at 30°c.the highest and lowest mean number of eggs per female during adult life was 4.79 ± 1.36 and 3.75± 1.49 at 30 and 20°c, respectively. the results of this study can be used to predict the developmentand population dynamics of b. rubrioculus.