FIELD-EVALUATION OF AND MODELING THE IMPACT OF 3 CONTROL METHODS ON THE LARVAL DYNAMICS OF OSTRINIA-NUBILALIS (LEPIDOPTERA, PYRALIDAE)

Impact of 3 control methods on larval European corn borer, Ostrinia nu bilalis Hubner, dynamics on corn, Zee mays (L.), was evaluated under f ield conditions at Versailles, France. The control methods studied wer e a chemical insecticide, Beauveria bassiana Vuillemin (Deuteromycotin a: Hyphomycete), and a transgenic corn hybrid. The experimental study showed that B. bassiana control was similar to chemical control. The t ransgenic hybrid control was always very high throughout the corn cycl e studied. A substantial decrease of B. bassiana and chemical control efficacy was observed with an increase in the delay between treatment and infestation. The complementary studies of B, bassiana persistence, control impact, and pathogen contact showed control-larval behavior i nteractions, which could explain this decrease in efficacy. To take in to account the main factors that condition control efficacy, a modular and mechanistic model was proposed to describe larval dynamic and con trol impact. The proposed control model made it possible to integrate O. nubilalis dynamics, and thus to describe the time response of contr ol.