Sterile fruit flies reduce pests’ numbers

Releases of sterile fruit flies at two Australian locations have significantly reduced Queensland fruit fly numbers.

The pilot, which ran from September 2019 to mid-April 2020 in Hillston, NSW and Cobram, VIC  involved releasing sterile fruit flies each week from a plane and is part of the Hort Innovation research project – Post Factory Pilot of SITPlus Fly production.

“The sterile fruit fly releases have worked well so far and are widely supported by local growers and community. The program is a very useful complement to the regional fruit fly management strategy,” said Cobram agronomist Russell Fox.

“The timing of the SITPlus project has been ideal to fit in with our area wide management activity,” said Goulburn Murray Valley regional fruit fly coordinator Ross Abberfield. “In Cobram, the sterile fruit fly releases contributed to an 83% reduction in Queensland fruit fly activity.”

“The rate of capture of wild male Queensland fruit fly in traps is on average 10 times higher in Mooroopna than in Cobram where sterile flies are being used,” said Plant and Food Research New Zealand plant and food scientist, Lloyd Stringer.

In Hillston, initial analysis indicates wild Queensland fruit fly were detected in very low numbers in town and almost undetected on nearby farms. Residents claimed they were able to eat their backyard fruit for the first time in years.

The project is a pilot that enables grower groups to confidently consider the Sterile Insect Technique, or SIT, for management of Queensland fruit fly. The project is testing efficacy of Queensland fruit fly SIT in the field and rearing sterile flies in localised centres. It’s also testing the development of quality control procedures in the dedicated rearing out centres. The project also underpins economic modelling for future operational Queensland fruit fly SIT use.

“A well-established method of pest insect control, the sterile insect technique is based on the mass rearing, sterilisation, and release of targeted pest insects. Once released in the environment, the sterile insects’ mate with their wild counterparts which disrupts reproduction and suppresses pest population numbers,” Hort Innovation SITPlus Program Director Dan Ryan said.

“In the Goulburn-Murray Valley, an area-wide management program coordinated through Moira Shire Council has been in place since June 2017. This activity has included the removal of feral fruit trees, abandoned orchards, and neglected urban trees on both public and private land. This non-SIT area-wide management program activity has shown that Queensland fruit fly activity has reduced by 57 per cent,” said Abberfield.

Northern Territory declared banana freckle free

Queensland banana growers have avoided a serious biosecurity risk with the Northern Territory today officially declared banana freckle free.

The successful eradication follows a five year joint effort between the Australian, state and territory governments and the banana industry.

Banana freckle is a pest of banana leaves and fruit caused by a fungal pathogen.

Federal agriculture minister David Littleproud said the announcement would boost confidence for Queensland growers and the $1.2 billion Australian banana industry.

“Eradication is a tough business so this is a big win for some 700 banana growers across the country,” Littleproud said.

“Growers were staring down the barrel of up to $24 million a year in additional management costs.

“The disease posed a real threat to the livelihoods of many banana growers but swift action saw it contained to the Northern Territory before it was eradicated.”

The fungal disease isn’t a health risk but does stunt the growth of the plant and causes spotting on the fruit, making it less appetising and harder to sell, Littleproud said.

“Had the disease spread to Queensland strict controls would have been put in place and no fruit would have been able to leave the region to be sold to supermarkets across Australia,” he said.

The federal government contributed $6 million to the national response program led by the Northern Territory and assisted with surveillance, monitoring and response planning.

“The partnership between the Northern Territory and the Australian Banana Growers Council was an essential component of the eradication program. The efforts of banana growers who participated in the program in the Northern Territory should also be commended,” Littleproud said.

“Queensland is the powerhouse of the Australian banana industry. In 2016­­­­­­­­­­–17 North Queensland produced 94 per cent of Australia’s banana production for the year.”

Hybrid mega-pest threatening global food crops

CSIRO scientists have confirmed the hybridisation of two of the world’s major pest species, into a new and improved mega-pest.

One of the pests, the cotton bollworm, is widespread in Africa, Asia and Europe and causes damage to over 100 crops, including corn, cotton, tomato and soybean.

The damage and controlling the pest costs billions of dollars a year.

It is extremely mobile and has developed resistance to all pesticides used against it.

The other pest, the corn earworm, is a native of the Americas and has comparatively limited resistance and host range.

However, the combination of the two, in a novel hybrid with unlimited geographical boundaries is cause for major concern.

The CSIRO researchers in a paper published in the Proceedings of the National Academy of Sciences of the USA  provides clear evidence of the hybridisation of the two moths in Brazil.

“A hybrid such as this could go completely undetected should it invade another country,” Research Director leading CSIRO’s Biosecurity Risk Evaluation and Preparedness Program Dr Paul De Barro said.

“It is critical that we look beyond our own backyard to help fortify Australia’s defense and response to biosecurity threats.

“As Australia’s national science agency, we are constantly looking for new ways to protect the nation and technology like genome sequencing, is helping to tip the scales in our favour.”

While a combination of insecticides currently controls these pests well in Australia, it is important to study the pests themselves for sustainable long-term management world-wide.

The scientists confirmed that among the group of caterpillars studied, every individual was a hybrid.

“No two hybrids were the same suggesting a ‘hybrid swarm’ where multiple versions of different hybrids can be present within one population,” fellow CSIRO Scientist Dr Tom Walsh said.

The bollworm, commonly found in Australia, attacks more crops and develops much more resistance to pesticides than the earworm.

A concerning finding among the Brazilian hybrids was that one was 51 per cent earworm but included a known resistance gene from the bollworm.

Lead author of the paper Dr Craig Anderson, a former CSIRO scientist now based at The University of Edinburgh, believes the hybrid study has wide-ranging implications for the agricultural community across the Americas.

“On top of the impact already felt in South America, recent estimates that 65 per cent of the USA’s agricultural output is at risk of being affected by the bollworm demonstrates that this work has the potential to instigate changes to research priorities that will have direct ramifications for the people of America, through the food on their tables and the clothes on their backs,” Dr Anderson said.

New face in town to help keep Yarra Valley fruit fly free

The Victorian Government has funded the appointment of a Fruit Fly Regional Coordinator in the Yarra Valley to help protect horticultural production and keep the area fruit fly free.

While many methods are used to control fruit fly, the critical factor is people working together. In the current Action Plan, the role of the Regional Coordinator is crucial for ensuring industry, community and government cooperate to effectively manage fruit fly.

Bronwyn Koll has been employed by Agribusiness Yarra Valley to work directly with the fruit fly Regional Governance Group which includes representation from major horticultural producers, local and state government, and community members from the area.

Bronwyn’s two year appointment is part of the $6.7 million Managing Fruit Fly – Regional Grants Program to provide a coordinated and collaborative approach to fruit fly management across the Greater Sunraysia, the Yarra Valley and the Goulburn Murray Valley.

Bronwyn’s family has been growing fruit in the Yarra Valley for four generations, so she understands the local industry and is passionate about protecting it for future generations.

“My top priority is to work with Yarra Valley fruit and vegetable industries, council and the local community to keep the Yarra Valley free from Queensland fruit fly.”

“Our fresh produce industries and amazing edible home gardens in the Yarra Valley are very valuable assets and worth protecting,” Koll said.

Based in Wandin, Bronwyn will be responsible for coordinating the implementation of the Yarra Valley Fruit Fly Regional Action Plan that was developed collaboratively by industry, government and community in the area.

Some of the tasks include working with the Yarra Valley horticultural community to reduce the risk of fruit fly entering the Yarra Valley, establishing a fruit fly trapping program as an early warning system to prevent fruit fly and engaging with the local community to build capacity to identify Queensland fruit fly.

“Building awareness within the Yarra Valley community is an integral part of the state wide approach to controlling the population and movement of Queensland fruit fly, and reducing the devastation it causes.”

“I look forward to also working with the Goulburn Murray Valley and Sunraysia Regional Coordinators. Together we play a significant role in protecting our fresh produce industries and our home gardens in Victoria.”

Image: Agriculture Victoria

Rentokil says pests cost $1.7 billion in lost revenue

Rentokil has released its own research into the threats and impacts of pests to businesses across Australia.

The report found that during 2014, Australian businesses affected by pest infestations also experienced a significant increase in their operating costs, collectively spending $796 million, while revenues declined by $1.7 billion. 

On average, an incident of pest infestation in Australian business lasted for just under three weeks. Food-based businesses were particularly vulnerable with 12 per cent of companies within this industry reporting losing more than 10 working days as a result of pest infestation. 

A significant 37 per cent of respondents experienced three incidents or more over a five-year period, and on average one pest infestation occurs just over every two years.

The report also revealed adverse impacts on staff morale (over 30 per cent) was the main impact on business costs in Australia, as a direct result of pest infestation. In addition, 20 per cent of businesses reported damaged goods, and replacement, maintenance and repair costs.

Alain Moffroid, Rentokil Initial Managing Director, Pacific said pests do not discriminate.

“Any size business operating in any type of industry across the globe can be vulnerable. Our analysts attribute this to our own population growth, urbanisation and heightened mobility, all of which is making it easier for mammals, birds and insects to spread, find shelter, feed, and reproduce – often at speed. As each year passes, businesses can become more prone to pests and are experiencing damaging – and costly – consequences.”

“A business’ reputation, relationships with its customers, clients, suppliers and of course its employees are all at stake when a pest infestation occurs in the workplace. At Rentokil we see first-hand how a single pest infestation, however small, can encourage repeat occurrences – particularly if the original issue is not effectively handled from the outset. A structured approach is crucial in ensuring any potential infestation scenario is covered to reduce the likelihood of an infestation taking place.”

Other key research findings:

  • A massive 83 per cent of Australia businesses have experienced incidences of pest infestations over the last five years
  • Almost 50 per cent of pest infestations in Australian businesses lasted between 1-2 weeks
  • The most common pests that affected businesses were cockroaches (51 per cent mice (34 per cent Ants (27 per cent and rats (25 per cent)
  • Just under 30 per cent experienced brand loyalty damage and damage to reputation or customer trust due to pest infestations