Temperature-dependent demographic parameters of Bryobia rubrioculus (Acari: Tetranychidae) on sweet cherry

Abstract

The brown mite, Bryobia rubrioculus (Acari: Tetranychidae), is a serious pest in orchards in Iran. Laboratory experiments were preformed in growth chambers at eight constant temperatures (15, 17.5, 20, 22.5, 25, 27.5, 30 and 32.5oC), 60 ±5% RH and a photoperiod of 16:8 h. (Light: Dark) using the sweet cherry leaves (Prunus avium). The survival rate (lx) was the highest at 15oC and lowest at 32.5oC. The life expectancies (ex) of 1-day adults were determined 38.28 to 11.51 at 15 to 32.5oC, respectively. There were significant differences between demographic parameters of B. rubrioculus at various temperatures. Net reproduction rate (R0), generation time (tG) and intrinsic rate of increase (rm) ranged from 5.83, 42.79 and 0.041 at 15oC to 0.67, 24.15 and 0.025 at 32.5oC. The gross fertility (4.4 eggs) was recorded at 32.5oC, and the highest (29.5 eggs) was at 20oC. 20oC is the optimal temperature for B. rubrioculus population growth.