Studies have shown that the inoculative release (75,000 female wasps per hectare, at whorl stage) of Trichogramma ostriniae Pang and Chen resulted >40% parasitism per generation of O. nubilalis Pang egg masses, significantly higher than control plots in field corn and sweet corn fields
The release of relatively small numbers of natural enemies that are expected to colonize, reproduce, and spread naturally throughout an area.