Locust plagues may sound biblical but they’re a real and present threat to Aussie farmers.
Locusts are tricky little critters to monitor. Ones that farmers fear, given the damage they can inflict on cereal, vegetable and other horticultural crops, including grapevines. A 2010 Australian East Coast infestation, for instance, was a doozie, creating $2 billion in crop damage.
So since taking on the post of Victorian Plague Locust Commissioner in 2018, Dr Kyla Finlay has had her hands busy keeping Australian Plague Locust numbers in check. From her office in Melbourne’s Attwood she coordinates boots-on-the-ground monitoring throughout the state with staff, councils, media and farming communities.
This vigilance is necessary given a locust swarm covering an area of 1km2 can munch through over 1000 kilograms of green vegetation in just one day.
Worst case scenario, a large swarm can cause up to 10% loss of a crop, according to Kyla. “Often the swarm will land during the night and will have eaten out a crop or pasture by daylight the following morning.”
Should we be worried, then? “Locusts will always present a risk,” Kyla cautions. “We had increased locust activity in late 2020 in the west and north-west of Victoria, after the heavy spring rainfall, but there’s no plague.”
Last spring’s higher-than-average rain dump in Victoria provided plentiful green feed, creating the perfect storm for locusts to breed, leading to higher than average sightings.
“We’re experiencing La Niña, which brings heavy rainfall to the east coast,” says Kyla. “If major migrations occur into central and northern Victoria, egg laying follows, and one or more new generations develop that season or in subsequent years.”
Victoria is faring well in terms of suppressing locusts, benefiting from the fact that a lot of the surveillance (and control if necessary) is done in the native range of the insect: north-west New South Wales and south-west Queensland.
“Control in those areas,” says Kyla, “means there’s less likely to be mass migrations into Victoria such as occurred in 2010. Locust populations in Victoria occasionally build up to relatively large numbers, but control is generally only needed locally.”
To carry out that local control, Agriculture Victoria is responding to reported sightings and taking note of egg laying and potential egg bed sites to follow up when the eggs hatch. “We’ll continue to do this throughout the summer and will re-assess in autumn,” says Kyla.
She’s hoping numbers will stay low. “When locusts aren’t behaving, there are a lot of phone calls and correspondence to attend to: coordinating and monitoring activities and keeping regional staff, local councils, farming communities and landholders abreast of the current situation.”
Kyla’s career journey
When were you first bitten by the insect bug, so to speak?
At La Trobe University, when I was working on an insect that didn’t have a name as part of my honours year research. I was amazed that a relatively common insect didn’t have a formal scientific name – it was known as “Australian voucher specimen 3 (AV3)”. It was then I discovered that many insects were unnamed. In my PhD studies, I got to officially name some of the unnamed insects I was working on.
What’s the draw about working with insects?
We know how many stars are in the sky, but we don’t know how many insect species there are on this planet. Just think what we could discover.
In one of your past jobs, you curated fleas at London’s Natural History Museum…
I was curating the Rothschild collection of fleas. Charles Rothschild, the famous English banker, was an entomologist and collected fleas in his spare time: he donated his 250,000-plus flea collection to the Museum. My job was to database re-house the flea collection but I also got to view some of Charles Darwin’s beetles and the original archaeopteryx fossil (a 150-million-year-old feathered, winged dinosaur of similar size to a raven that was dug up in Bavaria, Germany), plus I was granted free admission to all the exhibits!
Your fascination with locusts was sparked by a link between locusts and humans in terms of weight control, right?
Yes, I got interested in locusts from a fellow PhD student at Monash University – involved in Sydney University research – who explored nutrient regulation of protein and carbohydrate intake in locusts, which led to research into the benefits of a high protein diet to counteract obesity in humans. The ‘take home’ message from that research is that your body self-regulates your intake of protein, so you don’t tend to overeat.
Kyla on climate change
With a Melbourne University Postgraduate Certificate in Climate Change, Kyla argues we should be concerned about climate change, as hotter weather could trigger insect disease.
Predictions indicate temperatures will routinely reach beyond 30ºC over summer: a major threat to agriculture and food security.
Warmer temperatures may result in earlier flight activity and increased migration for insects. With shorter life cycles, numbers may also increase: already the case for moths, butterflies, beetles and aphids.
Temperature increases may also cause changes in species distribution. Temperate species may extend their distributions to higher latitudes or altitudes. In the Southern Hemisphere, southward shifts in distribution have been modelled for Queensland fruit fly.
A single change, or combination of changes, can have repercussions for the whole system. In short, more pests and disease issues.
For more about Australian Plague locusts, including the latest activity updates, how to report sightings and how to protect your garden and crops, visit Agriculture Victoria.