FIGURE 3.

Maximum-likelihood tree of GRs from P. saucia and other Lepidoptera. The tree was rooted by the conservative BmorGR9 (fructose receptor) gene orthologs. Branches of the putative CO₂ receptors are highlighted with green; branches of putative fructose receptors are highlighted with purple; branches containing “sugar-taste receptors” are highlighted with blue; and branches containing “bitted-taste receptors” are not highlighted. Node support was estimated with 1000 bootstrap replicates, and bootstrap values were displayed with circles at the branch nodes based on the scale indicated at the top left. Candidate PsauGRs are colored with red letters. The scale bar at the lower right indicates the branch length in proportion to amino acid substitutions per site. Psau, P. saucia; Harm, H. armigera; Bmor, B. mori.