Temperature Effect Study on Fecundity and Development of Tetranychus urticae, Koch. (Acari-Tetranychidae) on Different Host Plants

Spider mite, Tetranychus urticae, Koch., the most one important pests of plant in Egypt. Development and fecundity of this mite were studied on fig and tomato at three constant temperatures (20, 25 and 30°C), 60 ± 5% RH. The developmental time of immature stages ranged from 13.8 ± 1.6 & 10 ± 1.6 days at 20°C to 6.8 ±0.8 &4.6 ± 1.1 days at 30°C. The lower temperature threshold (t0) and thermal constant (k) of the immature stages were estimated to be 7.9 & 11.16°C and 119.351&85.185 degree days (DD), respectively. The average adult life span of females was determined to be 41.6 ± 3.0 & 34.8 ± 3.1 days at 20°C to 19.8 ± 1.3 & 15.1 ± 3.0 days at 30°C.