Stone fruit growers should prepare for an influx of Mediterranean fruit fly over coming weeks, the Department of Agriculture and Food has warned.
Department senior research officer Sonya Broughton said baiting by backyard and commercial growers was critical in suppressing numbers as part of any community wide strategy.
A mild, wet spring has contributed to a build-up in numbers and following recent hot weather, populations are now set to rapidly increase where control measures are not in place.
Dr Broughton cautioned those who had witnessed limited fruit fly activity so far this season not to be complacent.
“Very hot weather sometimes tends to reduce populations slightly, but also results in very short breeding cycles, enabling numbers to build up rapidly and become very difficult to manage,” Dr Broughton said.
The department recommends baiting as a pivotal management tool for commercial stone fruit growers and protecting fruit with fly-proof bags in home gardens.
“Baiting needs to be carried out weekly, spraying foliage with approved mixtures containing chemicals such as spinosad and malathion,” Dr Broughton said.
“This should be continued throughout the summer, even after fruit has been harvested to reduce fly numbers and help break the cycle.”
Dr Broughton said that close proximity of many properties in suburban areas meant that baiting was less effective because flies were attracted from nearby areas. In these cases netting a tree or bagging individual fruit, although labour-intensive, was the best chance of obtaining a maggot-free harvest for home gardeners.
Mediterranean fruit fly management has become much more challenging in the last two years following restrictions on the use of traditional cover sprays such as fenthion, but commercial growers and home gardeners were showing it was still possible to produce quality fruit, Dr Broughton added.
“And if you happen to be one of those home gardeners who are unable to control fruit fly effectively, removing the trees and growing something less susceptible may be the best course of action,” she said.
More fruit fly control information is available from agric.wa.gov.au
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