(A) Phylogenetic relationship of NPF and NPY precursors. The NPF precursors were obtained from Acyrthosiphon pisum, Aedes aegypti, Anopheles gambiae, Apis mellifera, Aphis gossypii, Bombyx mori, Culex pipiens, Drosophila melanogaster, Danaus plexippus, Nilaparvata lugens, Nasonia vitripennis, Schistocerca schistostatin, and Locusta migratoria; mammalian NPY precursors were obtained from Ovis aries, Mus musculus, and Homo sapiens. Most insect NPF peptides share an identical phenylalanine (F) instead of tyrosine (Y) at their C-terminus. The migratory locust genome contains two NPF1 precursors (NPF1a and NPF1b) and an NPF2 precursor. NPF1b, which encodes an 86 aa peptide, is hardly detected in the locust brain because of its extremely low expression level (Hou et al., 2015). (B) Phylogenetic relationship between insect NPF/Y receptors and human NPY recepetors. The receptors are obtained from A. pisum, A. aegypti, A. florea, B. mori, Culex quinquefasciatus, D. melanogaster, T. castaneum and L. migratoria, together with mammalian NPY receptors from H. sapiens. The locust NPFR is close to 'type two' mammalian NPYR (Homo Y2).