بررسی تاثیر دما روی پارامترهای جدول زندگی کفشدوزک شکارگر(Col., Coccinellidae) Stethorus gilvifrons در شرایط آزمایشگاهی

Temperature is one of the most important abiotic factors affecting the interaction of pests and their natural enemies. Current study was conducted to examine the effect of different temperatures on life table parameters of the predatory coccinellid, Stethorus gilvifrons (Col., Coccinellidae). The predatory coccinellids were originally collected from sugarcane fields of Khuzestan province and were reared on infected maize plants byTetranychus urticae Koch (Acari:Tetranychidae) at 15, 20, 25, 27, 30 and 34 ± 0.5 ̊C, %60±5 RH and a photoperiod of 16:8(L:D) h. in growth chamber. All of the cohort individuals were died at 38 ̊C. Net reproductive rates, intrinsic rate of increase, mean generation time, finite rate of increase and doubling time were estimated. Data was analyzed according to the age-stage, two-sex life table procedure. Means were compared using Paired Bootstrap Test (PBT) at 5% probability level. The obtained results showed that temperature significantly affected all developmental time and population growth parameters of the predator. Developmental time of S. gilvifrons decreased with increasing temperatures from 15 C̊ to 34 ̊C. The lowest and highest values of intrinsic rate of increase (rm) were 0.0003 (day-1) at 15 ̊C and 0.2052 (day-1) at 34 ̊C, respectively. The values of net reproductive rate were 1.025, 19.021, 38.58, 43.61, 68.61 and 70.05 (offspring) at 15, 20, 25, 27, 30 and 34 ̊C, respectively. The highest value for total fecundity was 249.52 (offspring) at 30 ̊C. The shortest and longest female longevity were 18.13 and 30.68 (day) at temperatures 34 and 25 ̊C, respectively. Mean generation time decreased with increasing temperatures, and the least value was estimated at 34C̊. The values of doubling time (DT) were 2311.08, 14.05, 6.23, 4.78, 4.14 and 3.38 (day) at 15, 20, 25, 27, 30 and 34 ̊C, respectively. Also, the values of finite rate of increase (λ) were 1.0003, 1.050, 1.117, 1.155, 1.182 and 1.227 (day-1) respectively at above mentioned temperatures. Present findings can be used for increasing efficiency of S. gilvifrons in integrated management programs against Tetranychid mites.