Life table parameters of Tuta absoluta (Lep:, Gelechiidae) at different constant temperatures under laboratory conditions

The tomato leafminer, Tuta absoluta (Meyrick), is a key insect pest of tomato in Iran and many other countries. The experiment initiated with 100 newly eggs and they were monitored daily in order to record the different development stages mortality. Also daily fecundity per female was recorded. This experiment that started by 20 female continued until death of all adult females. The effects of different constant temperatures, as the most important bioclimatic factor, on the life table and population growth parameters of tomato leafminer were determined under controlled laboratory conditions at 15, 20, 25, 30 and 35°C, 60 ± 5 % RH and a photoperiod of 16:8 (L:D) h. From the survival rate and fecundity schedule of T. absoluta at each constant temperature, the population growth parameters including net reproduction rate (R0), intrinsic rates of increase (r), finite rate of increase (λ), mean generation time (T) and doubling time (DT) were calculated with Jackknife method and SAS statistical software. According to the results, the highest and lowest survival rates at the beginning of adult emergence were 0.93 and 0.43 at 20°C and 35°C, respectively. Life expectancy of newly laid eggs were 46.23, 35.17, 29.53, 17.11 and 10.81 days and at the beginning of adult emergence were 27.22, 21.63, 16.33, 9.56 and 5.31 days at above temperatures, respectively. The lowest and highest values of intrinsic rate of increase were 0.07 ± 0.01 at 35°C and 0.21 ± 0.01 (d-1) at 20°C, respectively. The values of net reproductive rate were 3.31, 43.05, 37.54, 20.03 and 7.74 (females/female) at 15, 20, 25, 30 and 35 °C, respectively. The values of finite rate of increase at tested temperature were 1.01, 1.27, 1.14, 1.09 and 1.02 (d-1), respectively. Furthermore, the mean generation time decreased by increasing temperature, as its minimum value was obtained 10.24 ± 0.18 at 35°C. The values of doubling time at above mentioned temperatures were 12.06, 3.36, 3.68, 9.83 and 15.11 days, respectively. The results revealed that the population growth parameters of T. absoluta were affected by temperature as a critical abiotic factor.