The Department of Primary Industries and Regional Development is leading a national research project concerning native flies that seem to have potential as a supplementary pollinator to bees for South West avocado trees. The project is funded by Hort Innovation, with partners from across Australia.
The third year of trials was expanded in 2020 from an orchard in Busselton to include another new orchard at Pemberton, which all grow the Hass variety of avocadoes. On each property, one enclosure was populated with about 5000 western golden-haired flies, one with the western blue-bodied fly and - for the first time - a managed honey bee hive.
Department research scientist David Cook said this year's research sought to verify previous results from the first two years of the trial. Dr Cook said the results showed pollination exclusively by native flies produced yields two thirds of that achieved via open pollinated trees, where flowers could be pollinated by either bees and other insects in the orchard.
"Results from the past field trials showed the blue-bodied fly to be the most effective pollinator, visiting flowers three times more often than the western golden-haired fly and producing three times as much fruit as western golden-haired flies," he told margaretrivermail.com.au.
"If something were to happen to the bee populations sourced by orchardists, like a new pest or if a disease of bees and hives was introduced into Australia, then at least growers would have a viable other insect species they could use for pollination."