Pollinators facilitate the reproduction of many angiosperms, including food crops such as apple. Insects that provide important pollination services include beetles, flies, moths, native bees, and both managed and feral honey bees. Globally, honey bees (Apis mellifera) are the primary pollinator of apple. So far, the devastating varroa mite has not invaded Australian honey bee populations, but this is regarded as inevitable and will decrease both wild and managed honey bees and in turn, food security. In anticipation of the varroa mite arrival, we investigated potential alternative pollinators in two important Australian apple production regions - the Blue Mountains and Central West – both in New South Wales. During 2018 and 2019, insects were surveyed and collected directly from Pink Lady apple flowers. Loose pollen grains on the insects’ bodies were removed with sticky tape and then mounted onto microscope slides. From there, up to 300 pollen grains were counted and identified as either apple or non-apple.
Results/Conclusions
A diverse assemblage of insects visited apple flowers in NSW including many bees, ants, wasps, flies, beetles, and hemipterans, as well as arachnids. In both years, across all species, most apple flower visitors did not carry loose pollen on their bodies. The majority of the insects that did carry pollen were bees. Two species of highly social bee, the honey bee (A. mellifera) and a stingless bee (Tetragonula carbonaria), carried the most crop pollen, followed closely by allodapine (Exoneura sp.) and halictine bees (Lasioglossum sp. and Homolictus sp.). Hoverflies (family Syrphidae) had little loose pollen on their bodies and most of it was not apple pollen. Other flies and beetles had very low amounts of pollen on their bodies and did not carry different amounts of crop or non-crop pollen. Our results demonstrate that Australian native bee species are readily foraging on apple flowers, collecting apple pollen and are capable pollinators of this crop in NSW. Abundance is also an important factor to considers as most native bees occurred in low numbers, apart from stingless bees in the Blue Mountains. Suggesting that in the event of major honey bee declines, wild pollinators could safeguard apple pollination services.