Dung beetle iDNA as an additional tool for biodiversity assessment

Many dung beetles use mammal feces as a food source and build and move dung balls to lay their eggs and house their larvae. This behavior provides many ecosystem services, including nutrient cycling, secondary seed dispersal, soil excavation, and parasite and pest control.

Recent studies have shown that using genetic information from the guts of dung beetles (invertebrate-derived DNA, or iDNA) allows detection of mammals in a given habitat without intensive survey of the area. However, these studies used live or freshly killed beetles rather than preserved specimens.

In a study published in Integrative Conservationresearchers from the Xishuangbanna Tropical Botanical Garden (XTBG) of the Chinese Academy of Sciences tested whether dung beetles collected using conventional pitfall traps, which preserve specimens with an alcohol-based solution, could be used to extract, sequence and identify mammalian DNA. their guts.

The researchers extracted iDNA from the intestines of 18 dung beetles, comprising three species and three functional groups, collected from a seasonal rainforest in Xishuangbanna, China. The composition of detected species differed between the three functional groups, but shared the locally common wild boar and domestic cat. Paracoprids have preserved the largest number of mammal species (seven out of eight total recorded), including rare species such as the Asian black bear, southern red muntjac, and southern pig-tailed macaque. north.

They demonstrated that dung beetle specimens captured by conventional baited pitfall traps can preserve the DNA of mammalian species in their intestines. Conventional baited pitfall traps can capture different species of dung beetles with different mammalian diets over an extended period of time in the field.

“Our technique offers a viable alternative to traditional cafeteria experiments for understanding dung beetle-mammal interactions and may provide a valuable complementary approach to current mammal survey techniques,” said Akihiro Nakamura of XTBG.