Phylogenetic relationship of Haematobia irritans candidate gustatory receptors (GR) with those of Stomoxys calcitrans, Musca domestica, and Drosophila melanogaster. The H. irritans (Hirr) genes are labeled in black, while the S. calcitrans (Scal) and M. domestica (Mdom) genes are labeled in pink and teal, respectively. D. melanogaster (Dmel) genes are labeled in purple. Shaded regions identify four different bitter taste receptor clades that are expanded in S. calcitrans and M. domestica, as described in [44]. The color pattern of clades used in [44] is reflected here. Individual Drosophila genes are labeled on the edge to assist with finding them in the tree.