Airborne DNA is being used to detect insect species, a breakthrough for ecologists

The technique has ‘huge potential’ for monitoring decline in biodiversity, say scientists.

This story was originally published by The Guardian and is reproduced here as part of the Climate Desk collaboration.

Insect DNA has been gathered from the air and for the first time used to detect 85 insect species, according to scientists from Lund University in Sweden.

Bees, moths, flies, beetles, wasps, and ants have been identified in a study which raises hopes that airborne environmental DNA (eDNA) could become a useful tool in monitoring insect abundance and declines in biodiversity.

The study, which sampled air from three sites in Sweden, also detected evidence of plants, algae, fungi, and vertebrates, including a woodpigeon, fieldfare, hedgehog, red squirrel and short-tailed field vole, alongside the presence of domesticated animals – chickens, cows, and dogs.

The results, which have yet to be peer-reviewed, were presented last month at the British Ecological Society’s Ecology Across Borders conference, by the lead author, Fabian Roger.

“In the face of the biodiversity crisis, we desperately need better information on the status and distribution of species,” said Roger. “Our study is a proof of concept that shows that we can detect DNA from insects and vertebrates from air collected under natural conditions. This opens many exciting possibilities for species monitoring and detection, which could allow us to comprehensively monitor biodiversity at large spatial and temporal scales.”

Sampling of eDNA has so far focused on aquatic ecosystems, and is undertaken by ecological consultants surveying for great crested newts.

In this study, researchers compared airborne eDNA sampling with traditional insect surveys, including moth light traps and transect walks, which usually only pick up larger insect species.

While traditional light traps detected 48 species of moth, just nine moth species were detected with eDNA, although five of these were missed by the traditional traps. Of the 36 species of butterfly and bee identified by a transect walk, eDNA sampling detected five species.

The eDNA sampling was more successful at picking up a wider range of arthropod species, finding a total of 67 species at the light trap and 20 at the transect site.

According to Roger, developing airborne eDNA sampling to complement traditional methods will require increasing the sensitivity of the sampling to achieve more reliable detection and developing a greater understanding of how airborne eDNA is generated, transported and how it degrades.

“We are at the very beginning of exploring airborne environmental DNA for anything other than bacteria, pollen, or spores – and even there we have only scratched the surface,” he said. “Just because it doesn’t work perfectly out of the box doesn’t mean it won’t work ever, and the potential is huge.”

This story was originally published by Grist with the headline Airborne DNA is being used to detect insect species, a breakthrough for ecologists on Jan 5, 2022.