Abstract: Effects of rice transformed with cry1Ab (KMD1) on the biological characteristics of a parasitoid Apanteles chilonis (Munakata) through its host Chilo suppressalis were studied in the laboratory, using the 3rd, 4th and 5th instar larvae of C. suppressalis fed on the transgenic rice for a given time as hosts. The results showed that parasitized rates of host larvae fed on KMD1 were significantly (3rd instar) or very significantly (4th and 5th instar) lower than those of the control. Percentages of cocoon formation for hosts fed on KMD1 significantly reduced for the 3rd and 4th instar. Developmental period of the parasitoid pupa from hosts (3rd instar) fed on KMD1 was significantly shorter. Longevity of the male wasp from the 5th instar larva fed on KMD1 was significantly shorter. Length of wasp cocoon of KMD1 treatment was significantly shorter than the control. But no significant differences were detected in the developmental period of egg to larva, cocoon mass size, wasp emergence rate and sex ratio of the parasitoid between KMD1 treatment and the control.

Key words: Transgenic Bt rice, Apanteles chilonis, Chilo suppressalis, biological characteristics