Leptocybe invasa, the blue gum chalcid, is a well-known pest of Eucalyptus globally. Since it was first observed in the Mediterranean and Middle East in 2000, it has spread to other countries where Eucalyptus have been planted. Efforts to control it have included the release of a number of larval and pupal parasitoids. This report serves as the first record of the presence of Quadrastichus mendeli in South Africa, a parasitoid originally released as a biological control agent of L. invasa in Israel. The interactions and potential impacts on the other insects in the L. invasa galls will need to be investigated.