Evaluating the potential role of Australian stingless bees in tree crop horticulture

Abstract

Angiosperms (flowering plants) and animal pollinators (mainly insects, birds and mammals) have co-evolved and share a mutualistic relationship that has facilitated the diversification of both groups. Animal pollination is important for global food production to ensure food supply for the increasing human population, and pollinators are required for successful fruit and seed set in a number of economically important agricultural and horticultural crops worldwide. Like many other crops, mango - a predominantly tropical and subtropical crop which is also one of the most economically important fruit crops globally - benefits from insect pollination. Mango pollination has been studied in several countries; however, the role of insect pollinators is still not well understood due to inconsistent results. Several studies uphold the European honey bee, Apis mellifera as the most important pollinator of mangoes, while others found negligible contributions by honey bees to mango pollination. The accounts of mango pollinators vary greatly, suggesting region specific variability in pollinator community composition.

Overall, my research indicates that a native stingless bee and a hoverfly are the two most frequent visitors and efficient pollinators of KP mangoes in the Darwin and Katherine regions of Australia. As stingless bee colonies are located in the surrounding native vegetation, the distance of mango farms from native vegetation reduces their visits to mango flowers. My results suggest that stingless bees may visit mango flowers up to about 300m from the crop border. Bee deficits towards the centre of orchard blocks could be addressed by using managed stingless bee hives; however, hive deployment and stocking rates need to be determined first, requiring further research on this matter. Another important implication of my research for mango growers is the need to understand the harmful effects of pesticides on stingless bees, which may result in strong declines in the pollination services provided by stingless bees in this part of the world.

Date of Thesis submission	2022
Original language	English
Awarding Institution	Western Sydney University
Supervisor	James Cook (Supervisor), Robert Spooner-Hart (Supervisor) & James Makinson (Supervisor)