Abstract
The life history and predation rate of Neoseiulus barkeri (Phytoseiidae) feeding on Colomerus vitis (Eriophyidae), Tetranychus urticae (Tetranychidae) and Brevipalpus lewisi (Tenuipalpidae) were determined in the laboratory at constant temperatures of 25, 30 and 35 degrees C, relative humidity of 50 +/- 5 % and a photoperiod of 16:8 h (light:dark). Within the temperature range studied, the increase of temperature from 25-35 degrees C led to a shortened development period and an increased total predation rate and reproduction. Survival during immature stages development surpassed 94 % at all the temperatures from 25 to 35 degrees C. The highest fecundity (59.50, 48.25 and 35.30 eggs per female) was recorded at 35 degrees C, while the minimum (40.25, 31.00 and 20.50 eggs per female) was at 25 degrees C when N. barkeri fed on C. vitis, T. urticae and B. lewisi, respectively. It is demonstrated in the life table parameters that when the predatory mite N. barkeri is fed on C. vitis, the highest reproduction rates (r(m) = 0.195, 0.210 and 0.232 females/female/day) are obtained, while feeding on B. lewisi gave the minimum of reproduction rates (r(m) = 0.095, 0.105 and 0.115) at 25 degrees C, 30 degrees C and 35 degrees C, respectively. The population of N. barkeri multiplied 20.45, 22.63 and 24.89 times in a generation time of 16.80, 14.75 and 12.50 days when fed on C. vitis at the same temperatures mentioned above, respectively, while N. barkeri multiplied 10.70, 12.88 and 14.36 times in a generation time of 23.20, 21.11 and 18.08 days when fed on B. lewisi at the same temperatures, respectively. This shows that N. barkeri is a promising control agent for C. vitis, T. urticae and B. lewisi on grape trees.