From visit to emergence: Interactions between mycophagous Drosophilidae (Insecta, Diptera) and macroscopic fungi (Basidiomycota) and their patterns in ecological networks

Abstract

Ecological interactions are diverse, variable across space and time and not always well understood. The use of interaction network analysis has become a tool that promotes a deeper understanding on ecological and evolutionary processes. The interaction between insects and fungi is an interesting research model, helping to understand colonization dynamics and species specialization in spatially aggregated and ephemeral resources. Here, we describe the interactions between Drosophilidae species and the fungal basidiocarps in a subtropical forest in Brazil. Flies were collected when were visiting basidiocarps and then the basidiocarps themselves were also collected to obtain the emerging flies whose larvae fed on the fungi. We observed 31 species of drosophilids interacting with basidiocarps of 23 fungi species. An ecological network analysis was performed for the drosophilids breeding on basidiocarps and for those visiting them as adults. We found a specialized breeding network, with stronger interactions involving Hirtodrosophila and Auricularia and Zygothrica bilineata and a Marasmius species. Our results indicate the generalist habit of most Zygothrica species. The visitation network was highly specialized. Despite being well represented in the sampling, most Zygothrica species did not emerge from any fungal species. This study advances the knowledge on patterns of Drosophilid-fungi interactions and provides insights into their drivers.