ABSTRACT The genus Ophiocordyceps contains the most diverse assemblage of fungi that attack ants worldwide and are remarkably well adapted to the specific ecologies of their hosts. Desmidiospora myrmecophila Thaxt. is closely related to other ant-pathogenic species within Ophiocordyceps, possibly specific to queens, but the sheer infrequency of encounters and previously unsuccessful attempts to culture this fungus has precluded any meaningful assessment until now. A new record of Desmidiospora myrmecophila from Louisiana was found infecting a foundress Camponotus pennsylvanicus queen, the same host species favored by the more common and ubiquitous ant-pathogenic Ophiocordyceps unilateralis clade found in the same geographic locality. To evaluate a long-held assumption that these fungi represent synanamorphs of a single species, we sampled our Desmidiospora specimen along with the local O. unilateralis population for molecular comparison. We are able to present for the first time the in vitro characteristics and morphology of Desmidiospora myrmecophila, as well as a phylogenetic context for this fungus based on combined molecular analysis of representative members of the Ophiocordycipitaceae. Our results place the Desmidiospora myrmecophila lineage within the genus Ophiocordyceps, with a basal affiliation to the Ophiocordyceps unilateralis core clade; thus, in accordance to the “One Fungus–One Name” (1F1N) rule, we propose a new synonym to suppress Desmidiospora in protection of Ophiocordyceps, i.e., O. desmidiospora. These results further implicate this species as an important and quintessential example of cryptic diversity among an already taxonomically diverse and ecologically important group of fungi.

中文翻译：

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Ophiocordyceps desmidiospora，“僵尸-蚂蚁真菌”进化枝中的一个基础谱系

摘要 Ophiocordyceps 属包含最多样化的真菌组合，它们在世界范围内攻击蚂蚁，并且非常适应宿主的特定生态。Desmidiospora myrmecophila Thaxt。与 Ophiocordyceps 中的其他蚂蚁病原物种密切相关，可能是蚁后特有的，但由于遇到这种真菌的频率极低，而且以前培养这种真菌的尝试不成功，因此直到现在都无法进行任何有意义的评估。来自路易斯安那州的 Desmidiospora myrmecophila 的新记录被发现感染了一位创始人 Camponotus pennsylvanicus 女王，同一宿主物种受到在同一地理区域发现的更常见和无处不在的蚂蚁病原 Ophiocordyceps unilateralis 进化枝的青睐。为了评估一个长期存在的假设，即这些真菌代表单一物种的同形异形体，我们对我们的 Desmidiospora 标本以及当地的 O. unilateralis 种群进行了分子比较。基于对 Ophiocordycipitaceae 代表性成员的联合分子分析，我们首次展示了 Desmidiospora myrmecophila 的体外特征和形态，以及这种真菌的系统发育背景。我们的结果将 Desmidiospora myrmecophila 谱系置于 Ophiocordyceps 属内，与 Ophiocordyceps unilateralis 核心进化枝有基础联系；因此，根据“一个真菌-一个名称”（1F1N）规则，我们提出了一个新的同义词来抑制Desmidiospora以保护Ophiocordyceps，即O. desmidiospora。