What was it all about?

This project explored a method known as eDNA metabarcoding to determine which insect species and native plants are supporting successful avocado pollination.

Challenge

Inadequate pollination has been identified as one of the main contributors impacting fruit production in avocados, an issue experienced in south-west Western Australia where avocados typically produce large numbers of flowers but consistently yield low crops.

Response

Given the extensive application of DNA based monitoring in natural systems, use of this novel method in agricultural systems is underutilised despite it being a potentially powerful tool to identify a wide variety of organisms. Applications of this technology in food production systems are still in their infancy, with the exception of the soil sciences, and the field remains wide open for future DNA applications for both cultivated plants and domesticated animals.

This research explored how DNA metabarcoding can be used to improve monitoring of arthropod-plant interactions in agro-ecosystems by identifying entire arthropod communities,  their temporal and spatial variation, and the foraging resources and habitat preferences they rely upon. 

Benefit

The key outputs from this research were:

• Identification of potential pollinators for ‘Hass’ avocados in south-west Western Australia.
• Collection and identification of insect species that were not previously available on the online DNA barcode reference databases.
• Trial of a new method for isolating pollen and insect DNA from pan traps.

With further methodological refinement, eDNA-based surveys will form a strong compliment to current arthropod monitoring approaches in agriculture. eDNA metabarcoding of flowers in particular has the potential to revolutionise the way arthropod communities are monitored in agro-ecosystems, potentially detecting the response of pollinators and pests to different management practices, climate change, diseases, habitat loss and other disturbances.

This work was predominantly undertaken by a PhD student at Curtin University and worked closely with the Frontiers project Managing flies for crop pollination (PH16002). The addition of eDNA methods to that project will provide greater insight into the important pollinators of avocados in south-west Western Australia.