Phylogenetic relationships of OBPs from some insect species.
The mid-point rooted tree includes OBP sequences from Drosophila melanogaster and Drosophila mojavensis (Dmel, Dmoj; red branches), Anopheles gambiae (Agam; blue branches), Bombyx mori (Bmor; brown branches), Tribolium castaneum (Tcas; green branches), Apis mellifera (Amel; orange branches), Nasonia vitripennis (Nvit; yellow branches), Pediculus humanus (Phum; pink branches) and Acyrthosyphon pisum (Apis; cyan branches). The scale bar represents 1 amino acid substitution per site. The image was created using the iTOL web server (Letunic and Bork 2007). The accession numbers of the OBPs are listed in Table S1.