Masnerium wellsae Polaszek, gen. n., sp. n. is described from Merbein, Victoria, Australia. It is a primary endoparasitoid of the whitefly Aleuroduplidens wellsae Martin, described from the same type locality with identical collection data. Masnerium is most closely related to the genera Aleyroctonus Masner & Huggert, and Aphanomerus Perkins, but differs from both these genera in several morphological characters that are of primary importance at genus level in the Sceliotrachelinae.