Entomopathogenic fungi are widespread in terrestrial ecosystems and can be used as models for studying host-pathogen interactions. However, the associations between fungal virulence and ecosystem abundance, and the importance of virulence for ecological fitness are poorly understood. To study these associations, we investigated five selected strains from a natural community of the entomopathogenic genus Beauveria spp. representing different phylogenetic clades with distinct abundance and distribution patterns within an agricultural field and its neighboring hedgerow. We measured pathogen fitness traits related to virulence in a naïve host, the beetle Tenebrio molitor. We found that the two strains belonging to the most abundant Beauveria bassiana clade, which was the only clade represented in the agricultural field, exhibited the highest relative virulence in terms of host mortality, transmission probability, in vitro growth rate and germination speed. In addition, gene expression of specific virulence factors was higher compared to the strain belonging to the second most abundant B. bassiana clade. The study highlights the relevance of fungal virulence traits and adaptations to explain abundance patterns within natural communities of entomopathogenic fungi.

病原性真菌广泛存在于陆地生态系统中，可以用作研究宿主与病原体相互作用的模型。但是，人们对真菌毒力和生态系统丰度之间的关联以及毒力对生态适应性的重要性了解甚少。为了研究这些关联，我们调查了昆虫致病性白僵菌属自然界中的五个选定菌株。代表不同的系统进化枝，在农田及其附近的树篱中具有不同的丰度和分布方式。我们在幼稚的寄主-甲虫黄粉虫中测量了与毒力相关的病原体适应性状。我们发现这两个菌株属于最丰富的球孢 白僵菌进化枝是在农业领域中唯一代表的进化枝，在寄主死亡率，传播概率，体外生长速率和发芽速度方面表现出最高的相对毒力。另外，与属于第二丰富的球孢白僵菌进化枝的菌株相比，特异性毒力因子的基因表达更高。该研究强调了真菌毒力特性和适应性的相关性，以解释昆虫病原性真菌自然群落内的丰度模式。