The diapause hormone–pheromone biosynthesis activating neuropeptide gene,DH-PBAN, is expressed exclusively in seven pairs of DH-PBAN-producing neurosecretory cells (DHPCs) on the terminally differentiated processes of the subesophageal ganglion (SG). To help reveal the regulatory mechanisms of cell-specificDH-PBANexpression, we identified acis-regulatory element that regulates expression in DHPCs using the recombinant AcNPV-mediated gene transfer system and a gel-mobility shift assay.Bombyx moriPitx (BmPitx), a bicoid-like homeobox transcription factor, binds this element and activatesDH-PBANexpression. TheBmPitxwas expressed in various tissues, including DHPCs in the SG. Suppression ofDH-PBANexpression by silencing of theBmPitxsuccessfully induced non-diapaused eggs from a diapause egg producer. To the best of our knowledge, this report is the first to identify a neuropeptide-encoding gene as a target of the Pitx transcriptional regulator in invertebrates. Thus, it is tempting to speculate that functional conservation of Pitx family members on neuropeptide gene expression occurs through a “combinational code mechanism” in both vertebrate and invertebrate in neuroendocrine systems.