title: Understanding and managing avocado pollination in Chile
Creators: name: Dymond, Keira
Publisher: name: University of Reading
Year: 2024

description: Insect pollinators provide a critical ecosystem service by increasing the yield and quality of many 
globally important crops, with both managed and wild pollinators playing an important role. The 
protection of pollinators has gained increasing attention in recent years due to threats to pollination 
services such as climate change, pesticide usage, and natural habitat loss. However, implementing 
effective protective measures is challenging, as the level of crop dependency on insect pollination and 
the specific pollinator species important for different crops are often unknown. Moreover, the 
adoption of pollinator-friendly land management practices by growers frequently requires external 
support, which is often not available in many regions. The private sector has a vested interest in 
safeguarding pollinators given that numerous companies rely on insect-pollinated products within 
their supply chain and, thus, they have the potential to play a key role in supporting growers. However, 
at present, only a limited number of companies take action on pollinator protection, largely due to a 
lack of understanding regarding the risks faced by pollinators and the most effective support 
mechanisms. 
To investigate some of these knowledge gaps, this thesis used avocado (Persea americana) as a study 
crop. Avocado is a globally important insect-pollinated fruit, for which little is known regarding
pollination dependency, the contribution of wild pollination services and effective tools for 
sustainable management of avocado pollination. The first objective was to determine the extent of 
the contribution of insect pollinators to avocado production, and which insect taxa are the most 
important pollinators in different growing regions. The second objective was to investigate the impact
of proximity to natural habitats on pollinators in avocado orchards, with a focus on the important 
avocado-growing region of Chile. The final objective was to develop a tool that private sector 
companies can employ to develop effective strategies for safeguarding pollinators, using an avocado 
supplier company as a case study. Chapter 2 involved a literature review and meta-analysis of existing avocado pollination studies and
showed that insects contributed greatly to pollination, fruit set, and yield. Honeybees (Apis 
mellifera) were important pollinators in many regions due to their efficiency and high abundance, 
however, many wild pollinators also visited avocado flowers and were the most frequent visitors in 
over 50% of studies. Stingless bees (Meliponini spp) and blow flies (Calliphoridae spp) were identified 
as effective avocado pollinators, although for the majority of flower visitors’ data on pollinator 
efficiency was lacking.
Chapter 3 reports findings from pollinator surveys and controlled pollination experiments in three 
avocado orchards in central Chile. The result showed that over 70 different insect species visited 
avocado flowers and that wild pollinator abundance, visitation rate, diversity, and richness were 
significantly higher in areas directly adjacent to a natural habitat border. The pollinator exclusion 
experiments showed that insect pollinators contributed significantly to avocado production, with 
almost no fruit set when pollinators were excluded. Hoverflies and flies were identified as effective 
avocado pollinators due to their high flower visitation rate, with fruit set positively correlated with the 
abundances of these taxa. 
Finally, Chapter 4 developed a tool to assist companies in formulating and implementing effective
pollinator protection strategies. The tool comprises of seven activities, including new and existing 
desk-based methodologies, grower surveys, and informant interviews. The activities will help 
companies to 1) understand the threats to pollinators in different supply regions, 2) recognize the 
significance of pollinators to their business 3) assess the current implementation of pollinator actions, 
and 4) identify additional measures to better support pollinators. Application of this tool to an
international company sourcing and supplying avocado indicated that increasing knowledge transfer 
to growers and supporting their participation in environmental certification schemes could serve as 
effective strategies for pollination protection. The overall results from this thesis underscore the importance of insect pollinators in avocado 
production, with wild pollinators and the natural habitats which support them playing significant roles. 
To optimise yields, growers should implement land management practices that protect and restore 
natural areas within and around their orchards. Furthermore, the industry tool developed in this 
thesis provides private sector companies with a means to enhance pollinator protection by providing
a mechanism to develop effective safeguarding strategies. Its potential implementation could greatly 
benefit growers and pollination services worldwide.