Locust numbers are building across parts of southeastern Australia, prompting authorities to keep a close watch. The insects have been increasing in New South Wales and South Australia. Some have also been crossing the border into northwest Victoria. Within Victoria itself, the numbers have started to build up as well.
The rise has been linked to favorable conditions in recent seasons. There has been good weather over the last couple of years, and especially this season. A lot of rain has fallen, producing plenty of green feed. Those conditions have helped drive the increase in locust numbers.
For now, the damage to crops remains limited. Authorities describe the locusts as only having a bit of a nibble at this stage. The numbers are not yet high enough to cause too much damage, although some farmers may dispute that assessment. The current impact is therefore seen as relatively minor.
The greater concern lies further ahead, in spring. Any eggs laid now are expected to overwinter through the colder months. Those eggs will then hatch when spring arrives. It is that wave of hatching, rather than the present numbers, that worries authorities most.
The timing of any response will be important. About two weeks after the locusts hatch is considered the right moment to act. At that point, chemical sprays can be used to target them. The aim is to get on top of the numbers before they build further and before the locusts start flying.
Just how large the spring hatching will be remains uncertain. Authorities say the outcome depends heavily on the weather over the next couple of weeks. If the rain continues and conditions stay favorable, there could be a very large egg lay. For now, the scale of what is to come is still difficult to predict.
In the meantime, there is little that can be done to control the locusts directly. Authorities are instead asking farmers and the wider community to stay alert and report any sightings. Reports can be submitted through an online form, which can be found by searching for report locusts on the Agriculture Victoria website. That information helps authorities track where the locusts are now and where to look in spring.