Fungal-insect relations

Image: Tree cricket with multiple white cordyceps fruiting from it (credit Max Mudie)

Fungi and insects stand out as two of the most diverse groups in nature, leading to multiple evolutionary interactions that are crucial for ecosystem functioning. However, there is a notable research deficit on these relationships.

Fungivory includes activities ranging from the consumption of spores and hyphae to more complex relationships with fungal aggregates such as cords and fruiting bodies. Fungivore insects, including beetles, flies, fungus-growing ants, and termites, have developed specialized feeding behaviours that allow them to consume fungal tissues as their main food source. Cecid fly larvae, with paedogenic life cycles, influence the formation of pseudo-sclerotial plates (PSPs) in decomposing wood. This process enhances the deposition of persistent substrates rich in melanized compounds, serving as important carbon stores in woody debris and forest soils.

Some insects form mutualistic relationships with fungi where the fungi provide nutrients or shelter, and the insects contribute to spore dispersal. However, fungi are not always beneficial to insects; they can act as pathogens, significantly influencing insect population dynamics and community structure. A notable example are Cordyceps species, which infect and manipulate insect behaviour to increase spore dispersal. Additionally, some insects form symbiotic associations with fungi, particularly yeasts, which provide essential nutrients or detoxify harmful compounds in their diet.

Although many fungal and insect interactions have been studied for their economic importance, there are numerous lesser-known relationships that also play significant roles in ecosystem dynamics and functions. Understanding and valuing the entire spectrum of diverse interactions between fungi and animals is essential for comprehensive ecosystem management and enhancing forest biodiversity conservation.