In larval ， transcripts of the Rhesus-like glycoproteins and have been detected in the anal papillae， sites of ammonia (NH/NH) excretion; however， these putative ammonia transporters have not been previously localized or functionally characterized. In this study， we show that the AeRh50s co-immunolocalize with apical V-type H-ATPase as well as with basal Na/K-ATPase in the epithelium of anal papillae. The double-stranded RNA-mediated knockdown of and resulted in a significant reduction in AeRh50 protein abundance in the anal papillae， and this was coupled to decreased ammonia excretion. The knockdown of resulted in decreased hemolymph [NH] and pH whereas knockdown of had no effect on these parameters. We conclude that the AeRh50s are important contributors to ammonia excretion at the anal papillae of larval ， which may be the basis for their ability to inhabit areas with high ammonia levels.