Apple Pollination: Demand Depends on Variety and Supply Depends on Pollinator Identity

Abstract

Insect pollination underpins apple production but the extent to which different pollinator guilds supply this service, particularly across different apple varieties, is unknown. Such information is essential if appropriate orchard management practices are to be targeted and proportional to the potential benefits pollinator species may provide. Here we use a novel combination of pollinator effectiveness assays (floral visit effectiveness), orchard field surveys (flower visitation rate) and pollinator dependence manipulations (pollinator exclusion experiments) to quantify the supply of pollination services provided by four different pollinator guilds to the production of four commercial varieties of apple. We show that not all pollinators are equally effective at pollinating apples, with hoverflies being less effective than solitary bees and bumblebees, and the relative abundance of different pollinator guilds visiting apple flowers of different varieties varies significantly. Based on this, the taxa specific economic benefits to UK apple production have been established. The contribution of insect pollinators to the economic output in all varieties was estimated to be £92.1M across the UK, with contributions varying widely across taxa: solitary bees (£51.4M), honeybees (£21.4M), bumblebees (£18.6M) and hoverflies (£0.7M). This research highlights the differences in the economic benefits of four insect pollinator guilds to four major apple varieties in the UK. This information is essential to underpin appropriate investment in pollination services management and provides a model that can be used in other entomolophilous crops to improve our understanding of crop pollination ecology.

Insect pollination as an agronomic input: Strategies for oilseed rape production

“…Brassica napus is a morphologically very adaptable crop and as the plant grows it can respond to external and internal factors and moderate the number of flowers it produces and alter its investment in seed size up until senescence. Some crops may not have this flexibility, particularly those where key quality parameters directly relate to pollination such as size, shape or shelf‐life in apples and strawberries (Garratt, Breeze, et al., ; Garratt et al., ; Klatt et al., ). In this case, production of more, lower quality fruit cannot simply compensate for a drop in quality due to the considerable effect of quality on price.…”

Limited phenological and dietary overlap between bee communities in spring flowering crops and herbaceous enhancements

“…relatively understudied, solitary bees, including Andrena, have been identified as the most effective and economically important pollinators of apple, Malus pumila, a similar flowering Rosaceous crop (Garratt et al 2016). While wild pollinators of cherry are and control (open triangles) herbaceous habitats adjacent to these respective crops during late June-September.…”

“…The most pronounced bee declines have occurred in more agriculturally intensified regions, making these declines of particular concern due to the loss of pollination services in agriculture, valued at over US$200 billion to the global economy each year (Gallai et al 2009). Although the honey bee is capable of increasing yield in almost all animal-pollinated crops (Klein et al 2007), other research has highlighted the importance of wild bees as agricultural pollinators, whether providing the majority of flower visits to crops (Winfree et al 2008, Garratt et al 2016, improving the pollination efficacy of honey bees through competitive interactions (Brittain et al 2013), or more generally increasing fruit set regardless of honey bee abundance (Garibaldi et al 2013). Although the honey bee is capable of increasing yield in almost all animal-pollinated crops (Klein et al 2007), other research has highlighted the importance of wild bees as agricultural pollinators, whether providing the majority of flower visits to crops (Winfree et al 2008, Garratt et al 2016, improving the pollination efficacy of honey bees through competitive interactions (Brittain et al 2013), or more generally increasing fruit set regardless of honey bee abundance (Garibaldi et al 2013).…”

Using citizen science to examine the nesting ecology of ground‐nesting bees

“…This group encompasses many important pollinators, including those of high‐value crops such as apples (Garratt et al. ), but is facing diversity loss (Biesmeijer et al. ), declines in relative abundance (Bartomeus et al.…”

“…Solitary bees constitute roughly 250 species of wild bee in the UK, but there remain significant knowledge gaps with regard to their ecology (Wood et al 2016). This group encompasses many important pollinators, including those of high-value crops such as apples (Garratt et al 2016), but is facing diversity loss (Biesmeijer et al 2006), declines in relative abundance (Bartomeus et al 2013), and extinctions (Ollerton et al 2014). There are two principal resources that solitary bee populations require in order to survive and proliferate: suitable and robust nest sites for their offspring to successfully mature in, and sufficient forage material both for their own survival and to provision their young.…”