Ever since the introduction of transgenic crops one of the main concerns has been their potential impact on non-target organisms. In this study we looked at the impact of transgenic disease-resistant wheat on different clones of the aphid Metopolophium dirhodum. Looking at different clones allowed us to assess whether impacts depended on aphid clone and whether there were aphid clone x wheat line interactions (genotype x environment interactions). The
performance of 30 aphid clones on four different transgenic wheat lines and their corresponding control lines was
studied in a life-table experiment assessing the following aphid life-history parameters: development time, adult weight, daily fecundity, total offspring number and the fitness estimate F'i. As expected, we found significant variation among aphid clones for all the measured life-history parameters. However,our experiments did not reveal any major impact of the transgenic wheat lines on aphid performance. The only significant difference was found for total offspring number which was reduced by 3.33% on the transgenic wheat lines compared with the control lines. There was no evidence for a genotype x environment interaction between aphid clones and wheat lines. In sum, our results imply that the genetically modified plants used in this assay were of similar host plant quality as the non-transformed control lines and that the introduced transgene had no major effect on the performance of individual aphid clones.