Abstract: Diadegma insulare (Cresson), a parasitoid of diamondback moth (DBM), Plutella xylostella L., caught per sticky traps were used to indicate the presence of parasitoid in the habitats. The numbers of D. insulare caught were significantly different among habitats in 1993 and 1994. The parasitoid adults were caught in most habitats (crop or non-crop) except in the woodland’s centers and weedy areas with > 90% Agropyron repen (L.) or Asteraceae plus grasses as the majority of plants present. D. insulare is highly mobile and prefers to visit or stay longer in the habitats that have Daucus carota L. or wild Brassica species. These two weed species provided food sources or refuge for both parasitoid and its host (DBM). However, shelter of woodland edge with D. carota as the majority of plant presence attracted the highest numbers of D. insulare. Presence of D. insulare in most crop habitats especially in the field of tomato and corn suggests that these crops could be interplanted with cabbages that may enhance the role of D. insulare as a biocontrol agent of diamondback moth.