Female lures
From the October 2008 edition of Agriculture Today.
Climate change has raised the spectre of pests and diseases usually associated with the tropics finding a home in more temperate reaches of the globe.
If pests do move further south into Australia’s fruit and vegetable growing regions, Dr Katina Lindhout (pictured) and her team at NSW Department of Primary Industries’ Gosford Horticultural Institute hope to know sooner than most people.
They are developing new lures, or attractants, which can be used to monitor the incidence of Queensland fruit fly.
These lures will be tested against the fly’s destructive relatives in Papua New Guinea.
The economic damage Queensland fruit fly can cause in citrus, stonefruit and other horticultural crops is widely known.
However, if new fruit fly species arrive the consequences could be even more devastating.
"The lures currently available for female fruit flies are usually liquid," Dr Lindhout said.
"Fruit flies that are trapped rapidly decompose into a sticky mess, making them almost impossible to identify.
"As a result, most monitoring programs use dry lures, which are easy to handle and long lasting but unfortunately these only attract male flies.
"This introduces other problems because it’s the female flies that actually do the damage so they should be monitored accurately.
"This project builds on earlier work conducted by Andrew Jessup, who is currently working in Vienna."
A Co-operative Research Centre for National Plant Biosecurity project, it aims to develop dry lures and semi-solid lures that can attract the female flies.
These can be left out in the field for longer and they do not decompose the trapped insects too quickly, which makes insect identification much easier.
The lures being developed are food-based attractants designed to be placed inside plastic traps.
The lures are used in combination with a toxin that kills the flies when they enter the trap.
The lure testing is currently laboratory based, but in spring this year it will move into the field for testing in different climates.
"We are always looking for ways to improve our fruit fly surveillance, and a lure that is more effective at attracting and preserving female flies may help us to do this," Dr Lindhout said.
Dr Lindhout leads the project, with support from Horticulture Australia Ltd as well as researchers from the Department of Agriculture and Food in Western Australia, who will test the new lures on Mediterranean fruit fly.
"They don’t have Queensland fruit fly and they don’t want it, so whatever lures we produce they will be interested in," Dr Lindhout said.
"It’s also important for us in the eastern States to have an idea of how attractive the lures are to Mediterranean fruit fly, since that is a pest that we don’t currently have here either.
"We will also be testing our lures in Papua New Guinea under an Australian Centre for International Agricultural Research (ACIAR) project.
"PNG has a number of economically important fruit fly species that we don’t have in Australia.
"We want to do everything we can to keep them out of the country.
"Some of them aren’t particularly attracted to existing lures so we are testing new formulations to see if they are more effective.
"If they are, they could be deployed to support the Northern Australia Quarantine Strategy.
"It is important to monitor where these fruit flies are, as with climate change their range may move further south.
"It is possible that the PNG flies will find Australian conditions more favourable."
Contact Dr Katina Lindhout, Gosford, (02) 4348 1965 katina.lindhout@dpi.nsw.gov.au
