Abstract: There are many reports about resistance of transgenic Bt poplars to lepidopteran defoliators. Whether the poplars can resist haustellate mouth part pests and leaf-miners remains unclear. This study chose transgenic Bt poplar, Populus euramericana cv. Robusta'(R-94), as the material to investigate its resistance to a haustellate mouth part pest, Hegesidemus habrus, and two leaf-miner species, Leucoptera susinella (Lepidoptera: Lyonetiidae) and Lithocolletis paslorella (Lepidoptera: Gracillariidae) in both field and laboratory. Results showed that R-94 poplar had strong resistance to H. habrus in fields. Injury rates of R-94 leaves were respectively only 1.08% in pure stands and 1.1% in mixed stands respectively, while injury rate of 107 poplar (a non-transgenic variety) was 16.3% in the mixed stands. When H. habrus was fed with R-94 leaves in laboratory, the livability of nymphae was 19.9% after 7 days of feeding. However, the livability of nymphae reached to 56.8% after 7 days of feeding with leaves of 107 poplars. When H. habrus was fed with R-94 and 107 poplar leaves together, the insects significantly preferred 107 poplar leaves to R-94 poplar ones. Besides H. habrus, R-94 poplar also showed strong resistance to two leaf-miners species. Therefore, R-94 poplar not only has strong resistance to lepidopteran pest, but also has similar resistance to haustellate mouth part pests and leaf-miners.

Key words: Bt-transgenic R-94 poplar, insect resistance, Hegesidemus habrus, Leucoptera susinella, Lithocolletis paslorella