Do honeybees exert negative impacts on Australian native bees?

The European honeybee Apis mellifera is an introduced, invasive and abundant species in Australia. There are few places in urban areas where you won’t encounter honey-bees, suggesting they could compete with native bees for food – nectar and pollen.

These competitive impacts may be particularly severe in urban areas when the favourite food of our native bees – Australian native flowers – are relatively rare due to the predilection of gardeners to plant exotic flowers. Whether honeybees do impact native bees however is a very “sticky” and controversial topic: there was to date, little hard evidence Dr Kit Prendergast recently investigated this sticky topic in a Perth urban area. Kit found that the devil was in the details: at a very coarse level – simply overall native bee abundance, there was no association between honeybees and native bees. But the severity of competition isn’t uniform across all species – it varies. Species with larger body sizes, and therefore higher energy requirements, were negatively impacted by competition with honeybees, as were native bees that had a high overlap with honeybees in what flowers they foraged on (such as Hylaeine bees). Moreover, in terms of resulting in fewer species of native bees, this also varied by year, which means that in some years, when there might be a good flower bloom, native bees will be OK, but when there’s a “crunch” in native flora, or a surge in honeybee numbers, this can lead to fewer native bee species.

Honeybees not only compete with native bees for flower resources, but also can influence the networks of interac-tions between plants and their pollinators. Like all bees, honeybees visit flowers, but they differ from many native bees in being “super-generalists” – they will visit a large diversity of flora. This contrasts with many species of na-tive bees in Australia which are “fussy” – they only visit flowers from a narrow array of plants. It was found that indeed honeybees differed from all native bees in the “roles” they played in pollination networks. Importantly, honeybees had significant impacts on the pollination net-work properties, which were all are indicative that competition is occurring between the introduced honeybee and the native bees in bee-flower networks. In conclusion, the introduced honeybee occupies a dominant, distinct position in bee-flower networks in urban habitats in the southwest Western Australian biodiversity hotspot and has a major, potentially disruptive, influence on plant-pollinator network properties in these areas.

Citation: Kit S Prendergast, Kingsley W Dixon, Philip W Bateman, Interactions between the introduced European honey bee and native bees in urban areas varies by year, habitat type and native bee guild, Biological Journal of the Linnean Society, 2021, blab024,
Citation: Prendergast, K.S. and Ollerton, J. (2021), Impacts of the introduced European honeybee on Australian bee-flower network properties in urban bushland remnants and residential gardens. Austral Ecology.

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