a field study on the effects of the herbicide tribenuron methyl on biodiversity of wheat aphids (homoptera: aphididae) in mashhad, ne iran

to identify the impacts of chemical control of weeds on wheat aphids community, a field experiment was conducted in a completely randomized design with two factors, each in three replicates in a 20-ha wheat field. the herbicide treatment used tribenuron methyl, a broadleaf–selective herbicide and the control treatment not treated with herbicide. all other agricultural practices were the same for both treatments during the season. standard weekly sampling of the aphids associated with aerial parts of wheat plants commenced a week after herbicide application and continued for seven weeks. among the seven aphid species collected in this study, sitobion avenae, methopolophium dirhodum and, schizaphis graminum were the most abundant species. after square root transformation and normality test, analyzing data showed greater number of aphids in herbicide treatment than in control, but this difference was not significant. however, whether these differences can be explained by differences in density and diversity of weeds needs tritrophic interaction studies: weeds-aphids and natural enemies of aphids.