Neighbour-joining phylogenetic analysis of glutathione-S-transferases from Trialeurodes vaporariorum (Tv) and other insect species (accession numbers are given). Bootstrap values next to the nodes represent the percentage of 1000 replicate trees that preserved the corresponding clade. Positions containing alignment gaps and missing data were eliminated only with pairwise deletion. Acyrthosiphon pisum (Ap), Drosophila melanogaster (Dm). Acyrthosiphon pisum sequences were taken from http://www.aphidbase.com/aphidbase.