Gippsland growers and agronomists caught the weather on a sunny day in early September 2024 that was perfect for a workshop on the latest updates and strategies to spot and manage fall armyworm, a voracious caterpillar that has been spreading around the country since it was first detected in northern Australia in early 2020.

Growers are on alert for the incursion that has been advancing southwards, leaving a trail of destruction in its wake.

The invasive pest has recently been sighted in Gippsland, and the workshop gave local growers and agronomists information on the international, national, and local experience for growers on spotting and managing fall armyworm.

The event was hosted by Agriculture Victoria, in partnership with the Queensland Department of Agriculture and Fisheries and VegNET Gippsland.

‘Be prepared’ was the biggest message of the day.

“We’ve got low numbers currently that are not having much of an impact in the region, and it’s just helping growers be prepared for when we do get larger numbers in the region,” said Scott Botten, Horticulture Industry Coordinator Gippsland with Agriculture Victoria, who organised the workshop.

Dr Melina Miles presenting at the Gippsland growers workshop.

“Giving them information on the latest research, including pheromone trapping, resistance profiles, economics, impacts on the crop and best practice management.”

Fall armyworm has caused serious damage in Queensland and is a threat to more than 350 plant species, including maize, sweetcorn, cotton, rice, sorghum, sugarcane, wheat, and many other vegetable and fruit crops.

Attendees heard from four speakers passing along what they have learnt from the Queensland infestations. The session included information on pheromone blends, host plant preferences, identification, resistance surveillance, and more.

Dr Ramesh Puri, Extension Officer at Department of Agriculture and Fisheries Queensland, was one of those speakers.

“Early this year in January, February there was high influx of fall armyworm in Bowen,” he said. “There were lots of egg lays and infestations on our early sweetcorn crops. But as the days went on, in June and July fall armyworm incidents were very low and we caught less numbers of fall armyworm in our traps.

“But now as the warmer season is starting up, we have started looking into the increased number of fall armyworm. The growers are also informed about these, and they are aware of the managing practices that need to be taken.”

Attendees also heard from Dr Melina Miles, Principal Entomologist at the Queensland Department of Agriculture and Fisheries.

Tracking the pest is critical to understanding how it spreads, such as which crops and weed populations it can survive in, and whether it can survive the cooler Victorian winter.

“We put together a crop calendar that focuses on both crops and cover crops, as well as weed risks,” said Dr Miles.

And what that told us was really that there is an opportunity for fall armyworm to establish and to build up all year round. And it highlighted the need to monitor things like cover crops prior to the summer cropping period.”

In response to fall armyworm’s initial detection, government and industry launched a major collaborative project to coordinate research and monitor and manage the pest.

That research has resulted in innovations such as RapidAIM, a network of low-cost, automated pest detection devices that provide real-time data on the spread of fall armyworm, which are now being rolled out across Gippsland.

“One of the things that is important is understanding what the patterns of fall armyworm activity are locally,” said Dr Miles.

“And to persist with monitoring, using pheromones traps and the Rapid Aim network will help with that so that we can get a continuous picture over a number of years of when fall armyworm’s active, when fall armyworm isn’t active, and how quickly it builds up over summer. And that will really help agronomists and growers to better assess the risk for crops at different times of the year.”

Dr Doung Nguyen, Research Scientist at NSW Department of Primary Industries and Regional Development, spoke on insecticide resistance surveillance for sustainable management of fall armyworm using phenotypic and genomic approaches.

Fall armyworm insecticide resistance is caused by genetic changes that result directly from insecticide use, also known as selection pressure. Selection pressure causes resistance to build up in the next generation as resilient parents produce offspring.

Repeated application of the same insecticide groups, improper spray techniques, and inappropriate chemical choices all contribute to this development of resistance.

Dr Vivian Mendez, Research Group Leader at Macquarie University, spoke on fall armyworm pheromone blends for improved monitoring and population estimation in Australia.

Female moths are the ones who release the pheromones to attract males. The male moths have a very high sensitivity to the pheromone of the females, so the females don’t need to produce high amounts. Just a few molecules will trigger the male to find the female. Because of this, it is female fall armyworm pheromones that are used in traps to lure the males.

There are geographical variations in pheromone blends. An example Dr Mendez provided was that the pheromone blend that the females produce in Florida, has different compounds to the females in Brazil.

In Brazil, one of the compounds that is part of their pheromones is not found in any other population of fall armyworm. This is taken into account when creating lures in different areas. To increase the effectiveness of your lures, mimicking the pheromones found in the local population is important. This knowledge from overseas was used and applied when it came to creating the traps in Australia.

To begin the session, attendees also heard from Shakira Johnson from AUSVEG who provided a grower biosecurity project update from Onside to introduce growers and agronomists to how the platform works in checking employees and visitors in and out of locations to assist in biosecurity measures.

MORE INFORMATION
Learn more and find resources in combatting fall armyworm online at the fall armyworm hub from Queensland Department of Agriculture and Fisheries.