Research on fungal diversity is of great importance due to its ecological significance and economic potential in the fields of medicine and food. The cost-effectiveness of dung beetle sampling, coupled with their fungivorous nature, offers a way for invertebrate-derived DNA (iDNA)-based assessments of fungal diversity. This supplements the environmental sampling DNA (eDNA) method and other methods used to monitor fungal diversity.

In a study published in Molecular Ecology Resources, researchers from Xishuangbanna Tropical Botanical Garden (XTBG) of the Chinese Academy of Sciences provided the first fungal diversity assessment utilizing iDNA metabarcoding. This method facilitated sampling and monitoring of fungal communities via the gut contents of dung beetles, showcasing its potential applicability for mycological studies and the conservation of fungi.

Researchers sampled two habitats (rainforest vs. rubber plantation) and seasons (dry vs. rainy) in tropical Xishuangbanna, southwest China. They extracted, amplified and identified 9259 unique fungi Amplicon Sequence Variants (ASVs) from the gut of three species of dung beetles (Paragymnopleurus sp., telecoprids; Onthophagus diabolicus, paracoprids; and Onthophagus cf. gracilipes, endocoprids).

Then, researchers extracted fungal DNA from 68 beetle guts, including 17 telecoprids (Paragymnopleurus sp.), 25 paracoprids (Onthophagus diabolicus), and 26 endocoprids (Onthophagus cf. gracilipes), from both habitats and both seasons.

By comparing these insect-derived DNA (iDNA) samples with previously published soil environmental DNA (eDNA) datasets from the same locality, researchers conducted a systematic evaluation of methodological differences between the two biomonitoring approaches.

They found that a single iDNA sample, specifically one dung beetle gut, can yield hundreds of fungal taxa, and the fungal diversity detected in these minute biological samples was quantitatively comparable to that obtained through conventional soil eDNA studies which typically required pooling multiple soil cores into composite samples for analysis.

This study demonstrates that the iDNA of dung beetles is a potent tool for the effective detection and monitoring of diverse fungal communities, which enhances the detection of fungal occurrences associated with seasonal precipitation patterns.

“The use of dung beetle iDNA provides a less labor-intensive field sampling method, facilitating the exploration and monitoring of fungal diversity even in the hyperdiverse tropical rainforest environments. This technique can address significant conservation-related queries, such as the impact of land-use alterations on fungal communities,” said Akihiro Nakamura from XTBG.