Role of predators in suppression of the european corn borer, Ostrinia nubilalis (Huebner), on sweet corn

Four experiments were conducted to study the role of predators in the control of European corn borer (Ostrinia nubilalis (Hubner)) on sweet corn and possible methods for enhancing predator activity. A commercial predator food attractant was used in combination with different formulations of conventional and microbial insecticides in a field experiment with early and late plantings of sweet corn in 1993, 1994, and 1995. The predator food attractant alone or combined with Bacillus thuringiensis treatment did not consistently affect density of coccinellid or anthocorid predators or ear quality at harvest.; The types of functional response from predators to varying densities of eggs and first instars of European corn borer were studied in a laboratory experiment. With few exceptions, the predators Coleomegilla maculata (DeGeer), Orius insidiosus (Say), and Chrysoperla carnea (Stephens) had a type II functional response to both eggs and first instars.; Releases of C. maculata and O. insidiosus either alone or together on individually caged sweet corn plants were evaluated to determine their ability to search for and consume eggs and first instars of European corn borer. Results showed that C. Maculata has more potential than O. insidiosus for further studies on inundative releases for control of European corn borer.; C. carnea eggs and larvae were field released on sweet corn to evaluate its potential as a biological control agent. Adequate control was not achieved with any of various rates and timings tested.; Potential use of C. maculata for commercial releases will depend on improvements in mass rearing and in predator release technology, and basic field studies for control of the European corn borer.