Even at the highest rate of parasitism observed in these experiments (about 15 percent daily parasitism), calculated parasitism over a five-day egg development period would result in only 66 percent parasitism. Thus, it is clear that considerable emphasis should be placed on improving existing strains of T. nubilale and screening and improving efficacy of additional species, such as T. ostriniae or T. brassicae, to identify more effective strains that can be used as inundative controls of European corn borer.
Integration of inundative biological control agents in existing IPM systems requires an agent with sufficient efficacy and low enough cost that it will compete in the current pest management system. Using partial budget analysis and preliminary estimates of efficacy and cost, I evaluate the potential use of Trichogramma for controlling European corn borer in several corn commodities in the United States. Prevailing economic conditions constrain the use of T. nubilale in field corn. Even with substantial technical improvements, such as increases in efficacy and reductions in cost, T. nubllale is unlikely to be used in field corn. For fresh market sweet