eDNA metabarcoding of avocado flowers: ‘Hass’ it got potential to survey
arthropods in food production systems?
Abstract
In the face of global biodiversity declines, surveys of beneficial and
antagonistic arthropod diversity as well as the ecological services that
they provide are increasingly important in both natural and
agro-ecosystems. Conventional survey methods used to monitor these
communities often require extensive taxonomic expertise and are
time-intensive, potentially limiting their application in industries
such as agriculture, where arthropods often play a critical role in
productivity (e.g. pollinators, pests and predators). Environmental DNA
(eDNA) metabarcoding of a novel substrate, crop flowers, may offer an
accurate and high throughput alternative to aid in the detection managed
and unmanaged arthropod taxa (e.g. flower-visiting insects and potential
pollinators). Here, we compared the arthropod communities detected with
eDNA metabarcoding of flowers, from an agricultural species (Persea
americana - ‘Hass’ avocado), with two conventional survey techniques;
Digital Video Recording (DVR) devices and pan traps. In total, 80 eDNA
flower samples, 96 hours of DVRs and 48 pan trap samples were collected.
Across the three methods, 49 arthropod families were identified, of
which 12 were unique to the eDNA dataset. Alpha diversity levels did not
differ across the three survey methods although taxonomic composition
varied significantly, with only 12% of arthropod families found to be
common across all three methods. This study demonstrates that eDNA
metabarcoding of flowers to detect visiting arthropods, although in a
developmental stage, can complement traditional survey methods and
increase the diversity of taxa detected with implications for both
natural and agro-ecosystems.