Abstract: Two collembolan species were collected from paddy fields and identified as  Entomobrya griseoolivata (Packard) and Bourletiella christianseni Banks. Population densities of E. griseoolivatain Bt rice field were significantly higher than that in the control, the XS11 rice field. Cry1Ab insecticidal protein was detected in theE. griseoolivata fed with Bt rice (KMD1 and KMD2) litter in the laboratory. Results from the laboratory studies on predation and functional responses by Microvelia horvathi Lundblad adults showed that all the functional responses of the predator toE. griseoolivata fed with the litter of either Bt rice or the control rice XS11, whether by single or three M. horvathiadult(s), followed the Holling Ⅱ type response. The daily predation, instantaneous attacks constant and handling times of them were not significantly different.

Key words: Transgenic Bt rice, Entomobrya griseoolivata, Microvelia horvathi, predation, functional response