In order to confirm the effect of pest control using intercropping with different crops, investigation was conducted to study the population dynamics of insect pests of maize and their natural enemies in the habitat of sweet corn monoculture or intercropping with other crops (mung bean, kidney bean, sweet potato or peanut) by the method of eyeballing. Damage by Asian corn borer (ACB), Ostrinia furnacalis (Guenee) between different habitats was also be analyzed and discussed. Results indicated that the amounts of two predator groups, spiders and ladybirds, increased in sweet corn intercropping habitats significantly. Individual number of spiders in the fields when sweet corn intercropped with mung bean and number of ladybirds in habitat of sweet corn intercropped with sweet potato were over 21% and 83% respectively more than that in sweet corn monoculture. The number of Trichogramma ostriniae Pang et Chen showed no significant difference between different habitats, with the parasitic rates of ACB eggs were over 86%. No significant differences was observed in number of ACB eggs, Spodoptera litura (Fabricius) or Rhopalosiphum maidis Fitch between sweet corn monoculture and intercropping habitats. However, the ACB damage rate in sweet corn intercropping habitats was less than that in sweet corn monoculture at harvest, with the least in sweet corn intercropped with mung bean habitat, in which the number of holes and larvae was decreased by 55.72% and 76. 70% respectively. Study suggested that sweet corn intercropping with other crops could be beneficial to conservation of natural enemies and control of insect pests in some extents.
