4.1.3. Hyperparasites of tropical tar spot fungi

Tropical tar spot fungi (Sordariomycetes: Phyllachorales), along with Erysiphaceae and Meliolales, are among the most frequently hyperparasitized fungal lineages (Cannon, 1991; Hawksworth, 1981). Parbery (1978) listed some common hyperparasitic fungi of Phyllachora and Linochora species, namely Phaeodothis winteri (Dothideomycetes: Pleosporales), as well as species of Cercospora, Mycosphaerella (Dothideomycetes: Mycosphaerellales), Seimatosporium (Sordariomycetes: Amphisphaeriales), and other dematiaceous fungi. Other potential hyperparasites of Phyllachorales are cited by Baker and Dale (1951), Sivanesan and Kranz (1975), and Sutton (1980). Caution is warranted when interpreting fungal associates of tar spot fungi. The anamorph–teleomorph connections in Phyllachorales are not well understood; asexual states may be misinterpreted as hyperparasites, and vice versa (M. Mardones, personal communication). Moreover, it may be difficult to determine whether an associated fungus is a hyperparasite of the tar spot fungus or simply uses the cavities or the lesions as entrance for direct plant parasitism (Hawksworth, 1981).
Hyperparasitic fungi of Phyllachorales use different strategies to infect their hosts. Some hyperparasites grow through the perithecial ostiole of the tar spot fungus to expose their conidiophores, whereas others form a narrow layer of conidiogenous cells closely adjacent to the inner perithecial layer of the phyllachoralean fungus and remain almost invisible on the leaf surface (M. Mardones, personal communication). The coelomycete Diplodia sp. (Dothideomycetes: Botryosphaeriales), for example, forms its pycnidia inside the ascomata of Phyllachora sacchari (Rao, 1967). Hyperparasitized colonies of Phyllachora can be recognized by their dull surface and the necrotized host tissue around them (Gams et al., 2004).