Dispersal of ³²P-labelled Trichogramma chilonis in rice field

The dispersal of ³²P labelled population of Trichgramma chilonis in rice crop was studied during kharif 2002 and 2003. In the experiments in kharif 2002, radioactivity on the rice leaf folder eggs was detected for a distance of 9–12 metre in southern direction (downwind sector). However, at North (upwind sector), the radioactivity could be detected for up to 3–6 metre range. Likewise, the data on radioactivity of the leaf folder eggs in all four directions clearly indicated that the labelled parasitoids moved more or less evenly for up to a distance of 6–9 metre from the release point during kharif, 2003.