Synergistic effects of non- Apis bees and honey bees for pollination services

Abstract

In diverse pollinator communities, interspecific interactions may modify the behaviour and increase the pollination effectiveness of individual species. Because agricultural production reliant on pollination is growing, improving pollination effectiveness could increase crop yield without any increase in agricultural intensity or area. In California almond, a crop highly dependent on honey bee pollination, we explored the foraging behaviour and pollination effectiveness of honey bees in orchards with simple (honey bee only) and diverse (non-Apis bees present) bee communities. In orchards with non-Apis bees, the foraging behaviour of honey bees changed and the pollination effectiveness of a single honey bee visit was greater than in orchards where non-Apis bees were absent. This change translated to a greater proportion of fruit set in these orchards. Our field experiments show that increased pollinator diversity can synergistically increase pollination service, through species interactions that alter the behaviour and resulting functional quality of a dominant pollinator species. These results of functional synergy between species were supported by an additional controlled cage experiment with Osmia lignaria and Apis mellifera. Our findings highlight a largely unexplored facilitative component of the benefit of biodiversity to ecosystem services, and represent a way to improve pollinator-dependent crop yields in a sustainable manner.

Per-visit pollinator performance and regional importance of wild Bombus and Andrena (Melandrena) compared to the managed honey bee in New York apple orchards

“…Boyle-Makowski (1987) found native bees, particularly Andrena and halictids, to be important apple pollinators during years of poor weather since honey bee visitation was low under these conditions. The value of wild pollinators compared to honey bees was similarly high on windy days, when Apis would not visit almond blossoms but wild bees would (Brittain et al 2013). Optimal bee density will be context and crop specific, varying with bloom density, distance of pollen source, as well as amount of competing floral resources surrounding the focal crop (Brittain 1933).…”

“…Wild pollinators complement Apis pollination of apple by handling flowers differently while foraging, by visiting flowers in different parts of the tree canopy, and/or by changing Apis foraging behavior in a manner that improves its pollinator performance (Brittain et al 2013;Martins et al 2015). Boyle-Makowski (1987) found native bees, particularly Andrena and halictids, to be important apple pollinators during years of poor weather since honey bee visitation was low under these conditions.…”

“…For crops that are self-incompatible, if similar relationships between pollen deposition and efficiency are established, further assessment of pollinator efficiency could be readily derived from pollen deposition. Even though establishing such relationships is time and labor-intensive, so is counting pollen tubes using fluorescence microscopy, the only other way to accurately estimate per-visit pollinator performance for specific pollinators (Brittain et al 2013).…”

“…Ideally, one could measure fruit and seed set from a single or multiple visits as has been done for crops like pumpkin (Artz and Nault 2011); however, because apple produces a mass display of blossoms, the odds of a visitor landing on a single flower under observation is low, rendering this method impractical during apple's short bloom period. Counting only viable pollen grains, by assessing pollen tube growth, has been effectively used for massblooming almond to look at pollinator performance, but such methods require specialized equipment and skill (Brittain et al 2013). Here, we employ an alternative method that experimentally establishes relationships between stigmatic pollen deposition and fruiting response (Cane and Schiffhauer 2003).…”

Nesting biology of an Oriental carpenter bee, Xylocopa (Biluna) nasalis Westwood, 1838, in Thailand (Hymenoptera, Apidae, Xylocopinae)

“…Because of the declining honey bee population worldwide resulting from the condition known as Colony Collapse Disorder (CCD; Oldroyd 2007, van Engeldorp et al 2008, Ratnieks and Carreck 2010, the use of widespread pesticides (Hopwood et al 2012), climate changes (Bartomeus et al 2011), and the increase in monotonous agricultural landscapes that reduce the biodiversity and the availability of foods for bees, the study of wild and/or domesticated non-Apis bees can provide useful information for complementary bee species that may help with the pollination of food crops in areas where keeping of honey bees colonies are being affected or restricted (Chagnon et al 1993, Wilmer et al 1994, Javorek et al 2002, Hoehn et al 2008, Brittain et al 2013. Until now, only a handful of non-Apis bee species have been used extensively in agriculture, e.g., Bombus terrestris (Linnaeus, 1758), Megachile rotundata (Fabricius, 1787), Nomia melanderi Cockerell, 1906, Osmia rufa (Linnaeus, 1758, and some stingless bee species (Westerkamp and Gottsberger 2000, Hogendoorn et al 2006, Greenleaf and Kremen 2006, Slaa et al 2006, Hoehn et al 2008).…”