Parasitism and predation of corn earworm (Helicoverpa zea) eggs in corn – sunn hemp cropping system and corn monoculture with release of Trichogramma in corn

Parasitism of corn earworm (Helicoverps zea) eggs in corn – sunn hemp intercropping system and Trichogramma + corn monoculture examined and compared with corn monoculture. The proportion of H. zea eggs parasitized was found to be significantly different in all three cases. The highest parasitism was found with the release of Trichogramma. Further, proportion of corn ear having at least one Orius spp was significantly higher in corn –sunn hemp intercropping system compare to corn monoculture. Howevever, the number of adult lacewing (Chrysoperla carnae) trapped in yellow sticky traps was found to be significantly higher in corn monoculture compared to corn –sunn hemp intercropping system. The sweet corn yield was highest in plots from Trichogramma released corn plots followed by corn – sunn hemp plots. Release of Trichogramma is the most reliable tool for biological control of H. zea, whereas, parasitism occurred at an intermediate level in corn – sunn hemp intercropping, which can be an important component of cultural management methods for H. zea.