« Obligate hyperparasitism is an interaction wherein one species of parasite is parasitized by a second species of parasite, which cannot on its own parasitize an uninfected host. We here use the term “parasitism” in an expansive sense, for instance to include the “kleptoparasitism” which may arise when one parasite differentially attacks and in effect “steals” hosts already infected by anothe rparasite (the primary parasite), as well as systems where one parasite lives intimately within the body of the primary parasite. This interaction is pervasive in nature. » ~ “The coexistence of competing parasites. Part II – Hyperparasitism and food chain dynamics”, R.D. Holt, M.E. Hochberg. J. theor. Biol. 1998.