Abstract: For evaluating the resistance of transgenic Xiaohei poplar with fusion protein gene of the spider insecticidal peptide and Bt-toxin C-peptide to Clostera anachoreta(Fabricius), the development and death of C. anachoreta larvae feeding on different transgenic Xiahei poplars (the 1st transgenic clone, TT1; the 3rd transgenic clone, TT3) or their non-transgenic control (CK) and the histological change in their midgets were investigated in the laboratory through the cage feeding method and oparaffin method. The results indicated that for the larvae fed respectively on TT3, TT1 and CK, the total duration of 5 instars were 35.63 d, 30.39 d and 28.74 d, respectively; the percentages of pupation were 12.1%, 29.3% and 44.3%, respectively; and the mean weights of pupae were 0.1077 g, 0.1714 g and 0.1893 g, respectively. Feeding on the transgenic plantlets prolonged the larval developmental duration and decreased the pupation rate and pupal weight. At the same time, feeding on transgenic plantlets restrained the ecdyses of larvae, increased their mortality, and resulted in deformation of pupae. Histological examination showed that the midguts of larvae feeding on transgenic plantlets were somewhat damaged, for example, loosing cellular arrangement and decreasing food in midguts and distorting structure, and the damage was more serious with the extension of time. Generally speaking, various effects of TT3 on C. anachoreta were stronger than those of TT1.

Key words: Populus simonii×Ｐ. nigra, spider insecticidal peptide, Bt, Clostera anachoreta, resistance