Environmental DNA to detect and classify avocado flower-visiting insects; Hass it got potential?

Mr Joshua Kestel1,2,3, Dr Bill Bateman1,2, Dr Nicole White1,2, Dr David Field3, Dr Paul Nevill1,2

1Curtin University, Perth, Australia, 2Trend Laboratory, Perth, Australia, 3Edith Cowan University, Perth, Australia

Abstract:

Pollinator surveys are necessary for assessing animal diversity and the ecological services they provide in the face of global declines. Such surveys rely upon direct observations and collections that are often laborious and require extensive taxonomic expertise. Alternative methods such as environmental DNA (eDNA) metabarcoding may, however, offer an efficient alternative. Application of eDNA metabarcoding is still in its infancy, and few studies have used eDNA to measure flower-visiting insect diversity. This study sought to test if eDNA could detect trace amounts of insect DNA from flowers of a horticultural species, ‘Hass’ avocado. Two eDNA assays were used targeting the COI and 16S genes. Environmental DNA results were compared against two other monitoring techniques: cameras and pan traps. In total, 80 inflorescences, 48 hours of camera footage, and 48 pan trap samples were collected during October 2020. Across the three methods, 44 insect families were identified (eDNA; N = 24, cameras; N = 21, pan traps; N = 26), of which 8 were unique to the eDNA dataset. Neither insect family nor species differed significantly for alpha diversity across the three methods tested. All three methods found that Diptera and Hymenoptera are the main floral visitors. Our results suggest that all three methods detect a similar number of insect families and species, although each collection method detected slightly different cohorts of insects. Therefore, we affirm that eDNA offers time-efficient and detailed classifications of floral-visitors, but suggest that it is most effective when used in conjunction with other techniques.


Biography:

My area of interest is in pollination biology, specifically, the genetic consequences of different animal vectors for the plants they pollinate. I completed my Bachelor of Science majoring in botany and genetics at the University of Western Australia (UWA). Subsequently, I undertook my Honours research project with UWA and Kings Park Science examining bird pollination of the common catspaw (Anigozanthos humilis subsp. humilis). Now I have commenced my PhD using environmental DNA metabarcoding to examine plant-pollinator networks in avocado orchards in south west Western Australia.

Date

Mar 21 - 23 2022
Expired!