No abstract

Genetically modified herbicide-tolerant (GMHT) rice may have impacts on arthropods in paddy fields. To detect the potential effects of GMHT rice on arthropods, the structure and feature of canopy arthropod community in fields of GMHT rice "Bar68-1" were compared with those of non-GM control "D68". The families with high relative abundance of sub-communities of arthropod in GMHT rice field and non-GM rice field are similar, while the families with low relative abundance are different. There is no significant difference between GMHT rice and non-GM rice in the diversity indices, which are species abundance, Shannon-Wiener diversity index, Pielou index, Simpson index, of arthropod communities (P>0.05), with the exception of Simpson index (D) in sub-community of natural enemy in no-pesticide treatment in 2007. Difference in dynamics of most indexes, accounting for 95.3% of all calculated indexes, of arthropod community between GMHT rice field and non-GM rice field are not significant in mid-tillering, late tillering, full heading stage and milk stage of rice. The results suggest that GMHT rice "Bar68-1" does not significantly affect the composition and diversity of arthropod community in canopy.

To safely and sustainably utilize genetic engineering techniques for crop production, greater understanding of the potential effects of genetically modified herbicide-tolerant (GMHT) crops on the ecological functions of predators is required. In the laboratory, we examined the functional and numerical responses of Cyrtorhinus lividipennis Reuter to eggs of brown planthopper (BPH), Nilaparvata lugens (Stå l), that were reared on GMHT rice Bar68-1; the untransformed parental cultivar, D68; or a BPH-susceptive rice variety, Taichung Native 1. All stages of nymphs and female adult of C. lividipennis, those either on GMHT rice or control plants, exhibited typical type II functional responses when fed on BPH eggs; the attacking rate and handling time of C. lividipennis on GMHT rice Bar68-1 was not significantly different from that on D68. The numerical responses of C. lividipennis on GMHT rice or controls fit Beddington's model; there were no significant differences in the parameters of numerical responses between GMHT rice Bar68-1 and D68. The results indicated that the functional and numerical responses of C. lividipennis to BPH eggs are not affected by GMHT rice Bar68-1.