Two new species of Aphelinidae are described from the State of Tamaulipas, Mexico: Coccophagus indefinitus Myartseva n. sp., a parasitoid of Parasaissetia nigra (Nietner) on mistletoe Phoradendron quadrangulare (Kunth) Griseb., huisache Acacia farnesiana (L.) Willd., and willow Salix humboldtiana Willd.; and Coccophagus tamaulipecus Myartseva n. sp. on an unidentified species of Coccidae on an unidentified plant. This represents a new host plant record and new parasitoid association for Parasaissetia nigra on mistletoe.
