رشد و نموی وابسته به دمای کرم ساقه خوار ذرت Sesamia cretica (Lepidoptera: Noctuidae)

Corn stem borer, Sesamia cretica Lederer is an important pest of corn and sugarcane across the globe. The development rate and thermal constant were determined at ten constant temperatures ranging from 12 to 36 (±1)°C, 50±10% RH and a photoperiod of 16:8 (L:D) h for the Varamin and Rey populations of the pest in laboratory conditions. Two linear models (ordinary and Ikemoto) were used to determine the lower temperature threshold (T0) and thermal constant (K) of different stages of the pest. Furthermore, the development rate at different temperatures fitted to 26 nonlinear models. No eggs were hatched at 12°C and only the incubation period was completed at 15, 35, and 36°C with a significant difference between the two populations. The data of both populations better fitted to the Ikemoto linear model and it estimated T0 of the total immature stages to be 14.11°C and 13.57°C for the Varamin and Ray populations, respectively. The K value for the egg, larvae, pupa, and the total immature stages were estimated to be 72.74, 586.88, 141.33, and 895.36 degree-day in the Varamin population and 79.05, 804.36, 145.28, and 945.10 in the Ray population, respectively. Validation assessment of the linear and acceptable nonlinear models based on Akaike information criterion (AIC) of the total immature stages showed that development time estimation of the best linear (Ikemoto) and nonlinear (Briere-1) models in comparison with observed values were close to each other for Varamin and Rey populations, respectively at fastest developmental temperatures in laboratory condition. These findings can be used to construct a forecasting model for appropriate control of S. cretica.