Date of this Version
Much of the research on hyperparasitism has been of a descriptive nature, based primarily on studies with dual cultures in synthetic media. The main contributions from these investigations concern the host range of the parasite, the mode of penetration and infection, and the morphological changes of the host and the parasite resulting from parasitism.
More recent studies on hyperparasitism emphasize the effect of environmental factors, especially nutrition, on the susceptibility of the host. Research on the physiology of hyperparasitism has been limited. Nevertheless, this important aspect of the problem should continue to receive increased attention as hyperparasitism is extremely amenable to basic research dealing with the physiology of diseases in general (1).
In contrast to the voluminous literature pertaining to dual culture studies, there is little information regarding the biology of hyperparasitism in nature. Furthermore, there is a dearth of conclusive evidence to indicate that interfungus parasitism is an important factor affecting the survival of fungi in their natural habitat. The association of the purported parasite with a moribund or dead fungus host is cited as evidence that hyperparasitism may occur in nature. It has not been incontrovertibly established in most cases, however, whether hyperparasitism in nature is the cause or the effect of the diseased host. It is indeed essential to determine the existence of hyperparasitism in nature. And if the time, place, and the nature of interfungus parasitism could be ascertained, it would undoubtedly give impetus and new direction to research aimed at controlling phytopathogenic fungi through this antagonistic phenomenon.
Selected literature pertinent to the foregoing topics on hyperparasitism is included in this review. Other reviews more adequately deal with some aspects of hyperparasitism discussed in this paper (2-8).
The survey of the literature pertaining to this review was concluded in January 1964.