Phylogenetic analysis. Phylogenetic analysis was done using over 100 representative OBPs from dipterans (magenta), hymenopterans (turquoise) and coleopterans (yellow). The light blue box shows that orthologs of A. gambiae OBP2 are conserved across Culex, Aedes, and Anopheles genera, but are absent in Drosophila. The orange box shows that this clade of OBPs includes the Culex (e.g. CquiOBP1) OBP that binds the oviposition kairomones (5R, 6S)-6-acetoxy-5-hexadecanolide. The lineage-specfic expansions in various insect lineages other than the OBP1 and OBP2 clades, which are discussed in the paper have been collapsed and the branch lengths equalized for simplicity of viewing.