Pestfacts Southeastern Key takeaways
- Australian plague locust activity has increased across Northwest Victoria and Central West NSW, driven by significant rainfall and green feed availability earlier this year.
- No crop damage has been reported yet; however, eggs laid this autumn will over-winter and may hatch in spring, posing a risk to crops and pastures.
- Landholders should monitor and mark suspected egg-laying sites now and promptly report any activity to Agriculture Victoria or NSW Local Land Services.
Australian plague locust activity has been reported in cropping regions of Northwest Victoria and Central West NSW.
While minimal damage to emerging plants has been reported, crops may be at risk after winter, when eggs laid by this autumn generation hatch during spring.
Here we summarise some information from these recent reports and cover the latest advice for affected landholders.
Recent Australian plague locust activity
There has been an increase in Australian plague locust (Chortoicetes terminifera) adult activity across grain-growing regions of Central West NSW and Northwest Victoria.
In Victoria, locusts have been reported to Pestfacts Southeastern as far south as Birchip and Patchewollock.
The Australian plague locust is a native species, inhabiting vast areas of inland pastoral regions of Australia.
There was significant rainfall across pastoral regions, including Western NSW and the Upper Mallee and Southeast SA during February and March. An increase in green feed availability has likely favoured the build-up of populations and recent migrations into nearby agricultural regions.
What’s the risk to crops?
To date, we have not received reports of widespread feeding damage to emerging or young crops in Victoria or New South Wales, and as cooler winter temperatures set in, locust activity will slow.
However, activity is expected to continue during May and soon, adult females that have sufficient fat reserves are likely to begin laying eggs.
These eggs will over-winter and can hatch during spring if soil moisture is sufficient, creating an increased risk of locust damage in advanced crops, and spring-sown crops and pastures.
Although this species shows a preference for grasses, all green plant material is at risk of damage. Both the hoppers (immature locusts) and adult stage will feed on pastures and crops.
Monitor locusts now
It is important to pay attention to egg-laying activity now to prepare for spring hatchings; locusts are more effectively controlled before they reach adulthood, particularly when nymphs band together.
If you find high numbers of adults or suspect egg-laying activity now, mark the sites with a GPS coordinate or a star picket, and continue to monitor these areas during late winter and spring for the emergence of nymphs.
For now, keep an eye and ear out for adults flying low and feeding in concentrated areas. Their movement can sound like loud, continuous buzzing or crackling. Adults will fly up in front of you if walking through the paddock or field.
If you’re in close range, you may even hear locust mating or courtship sounds, as short, pulsed chirps or trills.
If your property has experienced locust activity at any time in the past 20 years, inspect those areas again this autumn; where Australian plague locusts have bred before, they are likely to return.
Females can lay eggs roughly one week after mating, first conducting ‘test drilling’. This is when females push their abdomen into the soil, leaving tiny holes in the ground, which is a strong indicator that egg-laying is imminent.
Egg-lay often occurs in hard, compacted ground such as roadsides, contour banks and stock camps.
Report locust activity
In Victoria and NSW, locust sightings should be promptly reported to your state department of agriculture.
Victoria – Agriculture Victoria Plague Locust Online Reporting Form or 136 186
NSW – Contact your nearest Local Land Services Biosecurity Officer on 1300 795 299.
In NSW, landholders and land managers have a legal responsibility under the NSW Biosecurity Act to report actual or suspected locust activity within 1 business day.
More information
Australian plague locust, Agriculture Victoria
Australian plague locust, PestNotes, Cesar Australia and SARDI
Locusts, Australian Plague Locust Commission
Locusts and locust plagues, NSW DPIRD
Acknowledgements
This article was compiled by Julia Severi, Cesar Australia. Thanks to Kristy Bennetts (NSW DPIRD) and Dr Kyla Finlay (Agriculture Victoria) for providing regional updates to inform this article.
Cover image: Photo by Tim Lawson
