Temperature-Dependent Demography of Two Geographically Isolated Populations of Sesamia cretica (Lepidoptera: Noctuidae)

The pink stem borer, Sesamia cretica Lederer is considered as the main insect pest of maize and sugarcane worldwide. Reproductive and life table parameters of two populations of S. cretica were studied at 10 constant temperatures ranging from 12 to 36 (+/- 1)degrees C, 50 +/- 10% RH and a photoperiod of 0:24 (L:D) h for the larval stage and 16:8 (L:D) h for the other stages. At 12 degrees C, no eggs hatched and at 15, 35, and 36 degrees C only the incubation period was completed. The longest (135.81 and 156.49 d) and shortest (49.61 and 52.09 d) female life span were observed at 20 and 32 degrees C for the Varamin and Rey populations, respectively. The highest (181.66 and 180.94 eggs/female) and lowest (13.40 and 32.85 eggs/female) total fecundity of the Varamin and Rey populations were found at 20 degrees C and 34 degrees C, respectively. At the same time, these two populations had the highest intrinsic rate of increase (r) (0.0343 and 0.0349 d(-1)) at 30 and 27 degrees C, respectively. Similarly, both Varamin and Rey populations had the highest finite rate of increase (lambda) at 27 degrees C (1.0349 and 1.0355 d(-1), respectively). It was found that the geographical populations of S. cretica were different in terms of the life table parameters at the same temperatures, and this issue can affect the results of forecasting studies. Accordingly, it is suggested that in the major corn-growing areas, a comprehensive study should be performed on different pest populations to address their commonalities and differences for future managing programs.