SIMULATION-MODELS FOR EUROPEAN CORN-BORER POSTDIAPAUSE MORPHOGENESIS AND EARLY INFESTATION OF MAIZE IN MISSOURI, USA

The European corn borer is one of the most damaging insect pests to ma ize in the United States, Different methods exist for the estimation o f time of damage to corn by first generation European corn borer. The most commonly used method is the linear thermal constant concept of ph enology which by convention calculates cumulative thermal units from J anuary 1 or another arbitrary date. Linear and nonlinear models based on the thermal units concept developed were to predict and simulate po stdiapause development of the European corn borer and subsequent infes tation of the maize crop using early spring temperatures (May 1-15) in central Missouri. The developmental rates of European corn borer were obtained from growth chamber investigations that simulated those temp eratures, the operational temperatures being selected from a compilati on of archival meteorological data from 1948 to 1989. The linear and p olynomial regression models were developed to predict phenological sta ges of the European corn borer using thermal units as developmental ra tes. The models were compared against each other to determine the bett er predictor of estimation values: each explained 94 and 98% of the va riation in developmental stages, respectively, In addition, the models were tested against independent field data and both models gave good predictions of developmental stages, indicating that either model woul d be a good predictor.