To assess effects of Bt rice expressing a synthetic Cry1Ac1 gene for control Cnaphalocrocis medinalis (Guenee) (Lepidoptera: Pyralidae), we conducted laboratory tests to evaluate the potential impacts of Bt rice on non-target herbivore, non-target pollen-feeder and non-target predator. Also we investigated the community structure of arthropods in Bt and non-Bt rice fields during the rice-growing season in 2007 and 2008. There were no significant differences in development, survival and emergence of non-target herbivores, non-target pollen-feeder and non-target predators between Bt and non-Bt rice although tibia length of non-target predators with BPH feeding on Bt rice showed significantly longer than in non-Bt rice. In 2-year field study, a total of 43 familes in 10 orders were identified from 64,099 collected insects and a total of 29 species in 23 genera and 9 families were identified from 4,937 collected spiders. Abundance, Shannon’s index and family richness in insects and species richness in spiders were very similar between Bt and non-Bt rice for 2 years and there was no significant difference. The results indicated that the transgenic Cry1Ac rice tested in this study had no adverse effects on the rice insect and spider community structure in field condition and on the development, survival, emergence and adult fitness parameter of non-target arthropods in the laboratory conditions.

Biodiversity of arthropods in Cnaphalocrocis medinalis (Lepidoptera: Crambidae) resistant GM rice (CryIAc1) and non-GM rice fields. Sampling was conducted 15 times using sweeping net and electric aspirator. Biodiversity was analyzed with species richness and Shannon diversity index (H’). Total 28,275 arthropod individuals (12,413 in GM rice and 15,862 individuals in non-GM rice) were collected and there were 22 families, 34 genera and 36 species belonging to 8 orders. There were 19 families, 29 genera, 31 species in GM rice and 20 families 32 genera 34 species in non-GM rice fields. There was no significant difference in species richness and species diversity (H’) between GM and non-GM rice. Species diversity was significantly higher in non GM rice in the insect pest group only in middle and late of August .