A degree-hour phenological model to forecast the first invasion of Sesamia cretica (Lepidoptera: Noctuidae)

Abstract

Corn stem borer, Sesamia cretica Lederer, is an important pest of corn and sugarcane worldwide. The validation of a linear and some selected nonlinear models in semi-field and field conditions regarding the development time of the Varamin and Rey populations of S. cretica was performed. Our previously published laboratory data on the development rate and thermal constant of the pest for both populations were used as baseline information. The results showed that to construct a forecasting model, the lower temperature threshold of the Ikemoto model and estimated thermal constant of semi-field or field conditions could provide a more accurate model. In the management of corn stem borer, when the thermal constant of the environment reached 44874.45 DH and 51,644 degree-hour (DH) for the populations of Varamin and Rey, respectively, in the second generation on corn, which coincides with the peak of eggs, the necessary measures for inhibition should be prepared. Pest control was recommended when it reached 45857.01 DH and 52692.56 DH in Varamin and Rey, respectively, which coincides with the emergence of neonate larvae. Using these results leads to more successful pest management and saving time and financial resources.