آماره‌های جدول زندگی شته برگ یولاف Rhopalosiphum padi (Hemiptera: Aphididae) در سه دمای مختلف روی گندم رقم میهن

Bird cherry-oat aphid, Rhopalosiphum padi (L.) is considered as one of the most important pests of cereals due to its high damage and population dispersion. In addition, it is an important vector of barley yellow dwarf virus (BYDV) in Iran and different parts of the world. The biological characteristics and demographic parameters of this aphid were determined under the laboratory conditions at 15, 20 and 25 (±0.5)˚C, relative humidity of 60 ± 5% and a photoperiod of 16:8 (L:D) h on the Mihan wheat variety in the growth chambers of the Iranian Research Institute Plant Protection. In this study, the life table parameters were calculated using female-based procedure. The highest net reproductive rate (R0) was 55.09 female offspring/female at 15˚C and decreased to 53.81 at 20 ˚C and 49.17 at 25 ˚C. The intrinsic rate of increase (r) of the aphid was 0.526 and 0.387 per day at temperatures of 25 and 20 ˚C, respectively, and its lowest value was at 15˚C (0.244 per day). Furthermore, the finite rate of increase (λ) was estimated as 1.69, 1.47 and 1.27 per day at temperatures of 25, 20 and 15 ˚C, respectively. The longest mean generation time (T) was recorded as 16.40 days at 15˚C. This period was reduced to 10.28 and 7.39 days by increasing the temperature to 20˚C and 25˚C, respectively. In addition, the longest population doubling time (DT) was 2.83 days at 15˚C and the shortest time (1.31 days) was estimated at 25˚C. In general, the results of the present study showed that the maximum value of the intrinsic rate (r) and finite rate (λ) of increase were obtained at temperature of 20 and 25 ˚C and it also showed the high potential of aphid population increase at the mentioned temperatures on wheat.