Acquisition of novel functions caused by gene duplication may be important for termite social evolution. To clarify this possibility, additional evidence is needed. An important example istakeout, encoding juvenile hormone binding protein. We identified 25takeouts in the termiteReticulitermes speratusgenome. RNA-seq revealed that many genes were highly expressed in specific castes. Two novel paralogs (RsTO1,RsTO2) were tandemly aligned in the same scaffold. Real-time qPCR indicated thatRsTO1andRsTO2were highly expressed in queens and soldiers, respectively. Moreover, the highestRsTO1expression was observed in alates during queen formation. These patterns were different fromvitellogenins, encoding egg-yolk precursors, which were highly expressed in queens than alates. In situ hybridization showed thatRsTO1mRNA was localized in the alate-frontal gland, indicating that RsTO1 binds with secretions probably used for the defence during swarming flight. In contrast, increasedRsTO2expression was observed approximately 1 week after soldier differentiation. Expression patterns ofgeranylgeranyl diphosphate synthase, whose product functions in the terpenoid synthesis, were similar toRsTO2expression. In situ hybridization indicatedRsTO2-specific mRNA signals in the soldier-frontal gland. RsTO2 may interact with terpenoids, with a soldier-specific defensive function. It may provide additional evidence for functionalization after gene duplication in termites.