Numerous Bt rice lines expressing Cry protein derived from Bacillus thuringiensis Berliner (Bt) have been developed since 1989. However, the potential risks posed by Bt rice on non-target organisms still remain debate. The white-backed planthopper (WBPH), Sogatella furcifera (Horváth), is one of the most economically important insect pests of rice in Asian countries and also one of the main non-target herbivores of transgenic rice. In the current study, impacts of transgenic cry1Ab/vip3H+epsps rice (G6H1) with both insect and herbicide resistance on WBPH were evaluated to ascertain whether this transgenic rice line had potential risks for this sap-sucking pest under laboratory and field conditions. The laboratory results showed that no significant difference in egg developmental duration, nymphal survival rate and female fecundity was found for WBPH between G6H1 and its non-transgenic isoline (XS110). However, the development duration of nymphs was significantly shorter and female longevity significantly longer when WBPH fed on G6H1 by comparison with those on its control. To verify the results found in laboratory, a 3-yr field trial was conducted to monitor WBPH population using both the vacuum-suction machine and beat plate methods. Although the seasonal density of WBPH nymphs and total density of nymphs and adults were not significantly affected by transgenic rice regardless of the sampling methods, the seasonal density of WBPH adults in transgenic rice plots was slightly lower than that in the control when using the vacuum-suction machine. Based on these results both from laboratory and field, it is clear that our tested transgenic rice line will not lead higher population of WBPH. However, long-term field experiments to monitor the population dynamics of WPBH at large scale need to be conducted to confirm the present conclusions in future.

A 2-yr field study was conducted to assess the effects of transgenic japonica rice (KMD1 and KMD2) with a synthetic cry1Ab gene from Bacillus thuingiensis Berliner on population dynamics and seasonal average densities of five thrips species including Stenchaetothrips biformis (Bagnall), Frankliniella intonsa (Trybom), F. tenuicornis (Uzel), Haplothrips aculeatus (Fabricius), Haplothrips tritici (Kurd) and their general predatory flower bug, Orius similis Zheng as compared to the parental control rice line using the white, blue and yellow sticky card traps. Population dynamics and seasonal average densities of these five thrips species and their general predatory flower bug were not significantly affected by rice type. Additionally, the white sticky card trap was suggested to be the most suitable for monitoring the population of these five thrips species and their general predator. These results show that our tested Bt rice lines do not interrupt the population of non-target thrips species and their general predatory flower bug in the field, and also cannot result in more occurrence of these thrips species in the rice ecosystem.