Biological characteristics of citrus brown mite Eutetranychus orientalis (Klein) (Prostigmata: Tetranychidae) under different temperature and humidity conditions

This study aimed to determine the biological characteristics and life table parameters of the Citrus brown mite Eutetranychus orientalis (Klein) (Prostigmata: Tetranychidae) on lemon (Citrus limon (L.) Burm. f. cv. Meyer) at 25°C and 30°C temperatures with 50±5%, 70±5%, and 90±5% relative humidity. The total immature development durations of female individuals of E. orientalis were 12.25, 11.73, and 11.56 days, and 8.92, 8.83, and 8.48 days at at the above specified temperature and humidity levels, respectively. The total immature development durations of male individuals were 12.26, 11.65 and 11.62 days, and 8.67, 8.22 and 7.69 days, respectively, at the same temperature and humidity levels. The adult longevity of female individuals at 25°C and 30°C temperatures and 50%, 70% and 90% humidity levels were 11.03, 12.59 and 8.69 days, and 9.16, 9.63 and 10.10 days, respectively. The adult longevity of male individuals was 12.39, 16.86 and 15.16 days, and 10.74, 8.77 and 9.57 days at the same temperature and humidity levels respectively. The daily and total average egg numbers laid by the pest at 25°C and 50%, 70% and 90% relative humidity were 4.09, 4.03 and 3.36 eggs and 34.80, 31.27 and 24.37 eggs, respectively. At 30°C, the daily and total average egg numbers were 3.52, 3.28 and 3.21 eggs, and 26.40, 24.60 and 26.06 eggs, respectively. At temperatures of 25°C and 30°C, the intrinsic rate of increase (rm) values for the pest were recorded as 0.182, 0.191 and 0.174 for 50%, 70% and 90% humidity, respectively and 0.208, 0.207 and 0.221 day⁻¹, respectively. The net reproductive rate (Ro) at 25°C and 30°C temperatures, with the same humidity levels, was 21.38, 22.85, 15.62 and 16.16, 14.94 and 15.06 females/female/lifetime, respectively. The highest Mean generation time (T) of E. orientalis at 25°C was 16.78 days at 50% humidity, followed by 16.35 days at 70% humidity and 15.74 days at 90% humidity. At 30°C, the mean generation time under the same humidity conditions were 13.39, 13.08 and 12.27 days, respectively.