Mature (colored) bell pepper is a high value crop that must ripen to full maturity, which leaves them highly vulnerable to attack from pests. Peppers can suffer 85 – 90 % fruit loss from attacks by the European corn borer, Ostrinia nubilalis Hübner. In 2003 and 2004 we evaluated the use of Trichogramma ostriniae (Peng & Chen) alone, and in combination with conventional (acephate rotated with permethrin) and certified “organic” (spinosad) sprays to control O. nubilalis. Replicated small plot (0.0007 ha) experiments were conducted on four pepper varieties. Control plots received no applications and were spatially separated (137.2 m) from treatment plots to minimize contamination with T. ostriniae. Beginning at first fruiting, applications of insecticides and inundative releases of 30,000 to 50,000 T. ostriniae per replicate were made weekly. In 2003, cumulative fruit damage in T. ostriniae release and conventional spray plots was similar, but was significantly lower (P=0.033) compared with organic spray plots. No significant differences in cumulative fruit damage among treatments were observed (P=0.152) in 2004. There was significantly less fruit damage (P=0.003 and P=0.0006) in T. ostriniae release plots (57.8% and 34.6%) compared with control plots (89.1% and 52.4%) in 2003 and 2004, respectively. The results suggest that chemical applications of spinosad may be injurious to T. ostriniae adults. Trichogramma ostriniae alone can provide effective control of O. nubilalis in mature (colored) bell pepper compared to the conventional and organic spray regimes used here.