Understanding the data surrounding natural capital and the vital ecosystem services driving agricultural productivity is essential for effective management strategies. Currently, efforts to monitor these factors often depend on traditional survey methods, such as sweep netting and morphological identification, which can be challenging to apply on a large agricultural scale.
Environmental DNA (eDNA) metabarcoding offers a transformative solution by amplifying trace amounts of DNA left behind by various organisms from sources like soil, plant tissue, and even air.
A study conducted by Curtin University has introduced a novel DNA-capturing method that could empower farmers to enhance crop yields while simultaneously supporting environmental health. Researchers from the School of Molecular and Life Sciences utilized the powerful ‘eDNA metabarcoding’ technique to gain insights into insect interactions with avocado flowers at two Western Australian orchards.
Led by Dr. Joshua Kestel and Associate Professor Paul Nevill, the research team collected avocado flower bunches, which were then frozen, ground, and processed for DNA extraction.
“We use eDNA metabarcoding to effectively amplify the DNA from whatever interacts with that flower and that lets us work out who was there,” Dr Kestel said. “We are literally able to detect the footprints of a bee.”
eDNA metabarcoding has proven to be five times more effective in identifying unique pest species compared to using digital cameras to record plants, which is another innovative technique currently employed.
“Digital video recording is advanced, but eDNA metabarcoding is Star Trek level – we are talking about a different universe,” he said. He believes that adopting eDNA metabarcoding can significantly boost crop yields and enhance the efficiency of agricultural practices.
Farmers often spend considerable resources renting honeybee hives to promote pollination and increase their fruit harvests. However, Dr. Kestel highlights that native pollinators are frequently neglected in this equation, and their vital contributions to various crops and trees remain largely unrecognized.
“Honeybees aren’t big fans of avocado pollen and nectar: an avocado tree has about a million flowers, but less than 200 will be pollenated and mature into fruit,” Dr Kestel said. “Using eDNA metabarcoding allows us to detect pollinators, pests, and — quite conveniently — predator species which can help protect crops by eating these pests.”
Dr. Kestel highlighted the tremendous benefits of accurately identifying pests in crops or orchards, including their specific locations on the trees. This crucial information empowers farmers to introduce natural predators or, when necessary, apply pesticides in a more efficient and targeted manner.
Currently, pest management is largely generalized, leading to substantial costs and unintended consequences, such as the destruction of essential wild pollinators and natural pest controls. Dr. Kestel believes that while eDNA metabarcoding is still developing, its potential to revolutionize our approach to pest management is significant and could lead to much healthier ecosystems.
“While it’s not yet widely adopted, there’s growing interest in this technology because there’s a recognition of how powerful it is,” he said.
Journal reference:
- Joshua H. Kestel, Philip W. Bateman, David L. Field, Nicole E. White, Ben L. Phillips, Paul Nevill. Spatio-temporal variation in arthropod-plant interactions: A direct comparison of eDNA metabarcoding of tree crop flowers and digital video recordings. Ecological Indicators, 2024; DOI: 10.1016/j.ecolind.2024.112827