Abstract: The influence of habitats on the percentage parasitism of diamondback moth larvae, Plutella xylostella L. by Diadegma insulare was studied. Percent parasitism was significantly different among habitats. Parasitism occurred in all habitats with the exception of centre of the woodland. This suggested that D. insulare was very mobile in the heterogeneous habitats. Percent parasitism was high in most crop and non-crop (only when Daucus carota L. is present in the majority of plants) habitats, however, it was significantly influenced by the interaction between habitats and times (months or years) of observations conducted. The percentage parasitism decreased as the distance of treatments in corn fields, from the field edge increased, suggesting that the corn field is not the primary habitat for D. insulare. The possible effect of polyculture systems on the impact of D. insulare in diamondback moth management program is discussed.