Predicted to enable polypeptide N-acetylgalactosaminyltransferase activity. Involved in sexual reproduction. Predicted to be active in Golgi apparatus. Is expressed in embryonic/larval midgut. Orthologous to human GALNT14 (polypeptide N-acetylgalactosaminyltransferase 14) and GALNT16 (polypeptide N-acetylgalactosaminyltransferase 16).