A research conducted by the Department of Agriculture and Food Western Australia (DAFWA) has shown promising results in eradicating the Mediterranean fruit fly (Medfly), a highly destructive pest that costs an estimated $200 million worth of damages to West Australian crops each year.
DAFWA partnered with UK-based technology company Oxitec to conduct trials in late 2015 testing the effectiveness of genetically modified organisms. The trials included importing a Medfly strain sourced from the UK – where the male flies are genetically modified to include a self-limiting gene – and mating them with the local female Medfly. The GM gene prevents the female offspring from reaching maturity or laying eggs in the fruit, effectively reducing the next generation of Medfly.
Just over a year into the program, the results of the trials have been successful. DAFWA Director of Horticulture David Windsor told ABC Rural, “We got the results that we were hoping for. The mating competitiveness of the Oxitec flies, and of conventionally irradiated SIT flies, was very similar.”
Currently, the sterile insect technique (SIT) is used across the state to counter the growing numbers of the Medfly. In 2014, Western Australia introduced the program of sterile fruit flies – sterile male flies that underwent radiation were bred at the state’s Department of Agriculture and Food headquarters in Perth, scheduled to be released over a period of four years. Dr Windsor believes however that the genetically modified fruit fly will be not only more efficient, but also cost effective.
“Because the poor flies haven’t been bombarded with radiation, we expect them to be a bit fitter and healthier, and to actually survive longer in the SIT environment than irradiated flies do,” Dr Windsor said.
The appeal of the GMO option is that it does not rely on chemicals or toxins, but while the research has proven successful, it will still take some time before farmers benefit from it.
“The gene technology regulator applies a very robust process, and there’s a fair bit of paperwork that needs to go in to do the risk assessments,” says Dr Windsor. “Once that’s submitted, that process of assessment can take up to 12 months, so it really depends on how hard the regulator needs to look to be confident about the technology.”
Dr Windsor is optimistic that the assessments will be approved, with Oxitec having already conducted their own trials to ensure the safety of the GM flies towards human health and the environment.
“They’ve done work on, for example, feeding their [GM] flies to spiders and things like that just to have confidence that there’s no ill-effects on predators from eating flies, and that they’re not going to somehow change the environment in some unanticipated way. And as I understand, the results of those tests have been encouraging.”