Effect of temperature on the life history and development of Typhlodromus athiasae Porath and Swirski (Acari: Phytoseiidae) as a predator of Tetranychus urticae Koch (Acari: Tetranychidae)

The present study determined the effects of different temperatures on the life history parameters an d development of Typhlodromus athiasae Porath and Swirski (Acari: Phytoseiidae) for the first time. The stu dy was conducted at 20, 25 and 30 degrees C and the predators fed on Tetranychus urticae Koch (Acari: Tetranychidae) under laboratory conditions. Our results show that temperature significantly affected pre-adult and adult durations of T. athiasae. The adult longevity was calculated as 47.90, 22.88, 19.50 days for females, 26.11, 19.90, 20.46 days for males at 20, 25 and 30 degrees C, respectively. The adult females of T. athiasae laid 15.80 (eggs/ female), 17.20 (eggs/female) and 12.38 (eggs/female) eggs at the respective temperatures tested. The highest net reproductive rate (R0= 8.90 offspring/individual) determined at 25 degrees C but no significant difference was foun d among the other temperatures. The highest intrinsic rate of increase (r= 0.12 day-1) was observed at 25 degrees C an d 30 degrees C. Although the highest finite rate of increase (lambda= 1.13 day-1) was determined at 25 degrees C, no significant difference was observed between this temperature and 30 degrees C. Also, the shortest mean generation time (T=14.9 7 day) was obtained at 30 degrees C whereas the longest mean generation time (T=28.39 day) was observed at 20 degrees C. Ou r results revealed that 25 degrees C was more suitable for mass production even if the female and male of T. athiasae survived and reproduced at all temperatures. Consequently, our present results and the data to be obtained in greenhouse and field conditions will reveal the potential of T. athiasae as a biological control agent of T. urticae.