The evolution of a mutualism requires reciprocal interactions whereby one species provides a service that the other species cannot perform or performs less efficiently. Services exchanged in insect-fungus mutualisms include nutrition, protection, and dispersal. In ectosymbioses, which are the focus of this review, fungi can be consumed by insects or can degrade plant polymers or defensive compounds, thereby making a substrate available to insects. They can also protect against environmental factors and produce compounds antagonistic to microbial competitors. Insects disperse fungi and can also provide fungal growth substrates and protection. Insect-fungus mutualisms can transition from facultative to obligate, whereby each partner is no longer viable on its own. Obligate dependency has (a) resulted in the evolution of morphological adaptations in insects and fungi, (b) driven the evolution of social behaviors in some groups of insects, and (c) led to the loss of sexuality in some fungal mutualists.

中文翻译：

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昆虫-真菌互惠主义的生态学和进化。

共生主义的发展需要相互的相互作用，从而一个物种提供一种服务，而其他物种则无法执行或执行效率较低。昆虫与真菌共生中交换的服务包括营养，保护和传播。在本文所述的共生共生酶中，真菌可被昆虫消耗，或可降解植物聚合物或防御性化合物，从而使昆虫可获得底物。它们还可以防止环境因素，并产生对抗微生物竞争者的化合物。昆虫可以分散真菌，还可以提供真菌生长底物和保护作用。昆虫-真菌的共生关系可以从兼职过渡到专职，因此每个伙伴都不再能够独立生存。