COS 65-1 - Proximity to natural habitat affects wild pollinator compositions and pollination services in avocado orchards

Abstract: Insect pollination is known to increase avocado yields, with both managed honeybees and wild pollinators likely playing an important role. In Chile, the rapid expansion of avocado orchards has resulted in highly diverse natural habitats being replaced by plantations and this is potentially impacting the abundance and diversity of wild pollinators and thus avocado production. This study aimed to 1) identify what wild pollinators are present in avocado orchards and explore the relationship between pollinator abundance and diversity and proximity to natural habitat, 2) quantify the effectiveness of different insect taxa in providing pollination services to avocados and 3) measure the contribution to avocado production of insect pollinators and explore to what extent this varies with proximity to natural habitats. The study was carried out across 3 farms in central Chile in 2020, 2021, and 2022. Transect observations were carried out along a natural habitat gradient to understand pollinator abundance and diversity, video cameras were used to record data on pollinator flower visitation rate and controlled pollination trials (open, hand, and manual pollination treatments) were implemented to understand pollinator contribution to production.



The results showed that more than 60 different insect species visited avocado flowers and that pollinator abundance, visitation, and richness were significantly higher closer to natural habitats. However, this relationship was non-linear with 2 to 3 times greater abundance, visits, and richness adjacent to natural areas in comparison to further into the orchard. Honeybees and flies were shown to have a higher flower visitation rate and beetles a lower visitation rate in comparison to other taxa. The controlled pollination trials confirmed that insect pollinators contribute significantly to avocado production, with almost no fruit set when pollinators were excluded and likely higher yield at orchard edges. However, further studies are required to better understand how different natural habitats and wild pollinator compositions contribute to production. This study contributes to the growing evidence for the importance of natural habitats and wild pollination services in crop production and thus growers are advised to implement land management practices that protect and restore natural areas and wild pollinators.