Using airborne DNA to monitor insect biodiversity

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Biodiversity is in decline due to human use of land, exploitation and climate change. It is essential to monitor biodiversity on a global scale to closely counter this alarming trend. Because this is practically impossible with traditional methods, the last decade has seen a surge of solutions.

The development of environmental DNA or eDNA is an exciting new technology, offering a faster, more sensitive and more powerful tool for monitoring biodiversity. In aquatic ecosystems, monitoring species from environmental DNA (eDNA) has become one of the most powerful tools. Yet in terrestrial ecosystems, the power of eDNA for monitoring has been hampered by the local scale of the samples.

Scientists at Lund University have discovered that it is possible to detect insect DNA in the air for the first time. Using air from three sites in Sweden, they were able to identify the DNA of insects from 85 species. It offers the opportunity to explore a whole new way of monitoring terrestrial biodiversity.

These preliminary results will be presented at Ecology Across Borders (December 13-15) via an online poster by Dr Fabian Roger, who is currently working at ETH Zurich.

Insects detected included many essential species such as bees, moths, flies, beetles, wasps and ants. The study also showed evidence of insects and many species of vertebrates, including birds, mammals and some domestic species.

In many areas, insects are declining at an alarming rate, but we also know very little about the number of extant species. It is estimated that we have described 1 million of 5.5 million insect species on Earth. This means that it is essential to develop effective means of monitoring biodiversity.

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

Researchers detected airborne DNA from moths, as well as bees, flies, beetles, wasps and ants. Image from Wikimedia. Credit: Charles J. Sharp

DNA sampling in air offers advantages over traditional sampling methods. Insects are usually sampled using malaise traps, resulting in the death of the creatures. Alternatives, such as cross walks and moth trapping, require taxonomic expertise and typically focus on larger insect species. A DNA meta-bar coding approach means that multiple species can be detected from a single sample. Therefore, meta-bar coding of airborne DNA would speed up oversampling and allow scientists to scale up biodiversity surveys, all without harming the species that live there.

In this study, when the researchers compared the results with traditional surveys, they found some overlap in the species detected. Some species were not found with conventional methods, but the airborne DNA method could not select many species. For example, researchers found 48 species of moths in traps and nine species of moths using eDNA, with an overlap of 4. Being in its infancy, researchers have many ideas on how this can be done. be improved and are convinced that airborne DNA meta-bar coding can become a powerful tool for biodiversity monitoring.

Next, scientists will optimize methods to increase the reliability of barcode airborne DNA. They also need to better understand how DNA moves through the air. Fortunately, meteorologists and aerosol scientists have studied the movement of airborne particles for decades, providing a vast pool of expertise to expedite this work. Interestingly, the method can also detect invasive species or even early detection of disease vectors.

“We’re in the very early stages of exploring airborne environmental DNA for anything other than bacteria, pollen or spores – and even then we’ve only scratched the surface. One of the first challenges will be to optimize sampling and molecular methods to increase sensitivity and achieve more reliable detection. Next, we will need to understand how airborne eDNA is generated, transported and degraded. “ said Fabian Roger, who then added: “Just because it doesn’t work perfectly from the start doesn’t mean it will never work, and the potential is huge. “ Dr Fabian Roger will present his work at Ecology Across Borders.

This work is unpublished and has not yet been peer reviewed. This conference will bring together more than 1000 environmentalists to discuss the most recent breakthroughs in ecology.

Journal reference

  1. Roger F, Ghanavi H, Danielsson N, Wahlberg N, L̦ndahl J, Pettersson LB, Andersson GKS, Ol̩n NB, Clough Y. 2021 Airborne environmental DNA metabarre for terrestrial insect monitoring Рa proof of concept. bioRxiv, 2021.07.26.453860. DO I: 10.1101 / 2021.07.26.453860


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