Paper wasp,Polistes hebraeus(F.), nests appear to serve as reservoirs of fungi. Eighty-nine fungal isolates were obtained from larvae and meconia of this wasp collected on La Réunion Island. Thirty-one fungal genera were recovered and at least 52 species identified. These numerous molds and yeasts survive or grow as saprophytes in excreta; among them two genera were predominant,AspergillusandPenicillium. This mycoflora which is spread in the environment when the nest breaks up contains potentially entomopathogenic and phytopathogenic fungi,Aspergillus flavus, Aspergillus tamarii, Paecilomyces farinosus, Alternaria alternata, remaining viable after passing through wasp intestines.