KELLERBERRIN farmer Philip Maisey watched part of his crop be decimated by a swarm of locusts on Friday, only a few days after the Department of Primary Industries and Regional Development (DPIRD) warned broadacre farmers to monitor crops and pastures for Australian plague locusts (APL).
When he went to check on his sheep in the morning Mr Maisey noticed the locusts had started feeding on the edge of his paddock, but by the afternoon 40 metres of crop had gone.
“I had seen them about for a week or so but not like this,” Mr Maisey said.
After speaking to a neighbour about his options Mr Maisey decided against spraying them, instead letting sheep on the crop to utilise it as much as possible before it disappeared.
DPIRD’s warning for growers came despite relatively low activity of locusts during spring.
The delayed start to the growing season and protracted cold and wet conditions during spring have delayed hatchings in some areas of the grainbelt.
DPIRD research officer Dr Svetlana Micic said there had been localised reports of APL hatchings from Southern Cross, Narrogin, Katanning, York, Jennacubbine and Cadoux, posing a risk to some crops and pastures that were still green.
Ms Micic said it was important for landholders to monitor hopper and adult locust numbers and to undertake control measures, if required.
“While hoppers tend to generally avoid established green crops, when locusts begin to fly crops that are beginning to hay off are most susceptible to damage,” Ms Micic said.
“Locusts will hatch at variable times so it is important for growers to continue to monitor crops and pastures that are still green to determine if and when to start spraying.
“The main activity will be seen in pastures so look for early hatchings and hatching egg beds in places where there are bare patches, such as around dam banks, road catchments and along fencelines.”
Ms Micic said treatment measures to protect pastures were recommended, if the cost of controlling the pest exceeded the cost of replacing the feed.
“The threshold for treating pastures is 20 hoppers per square metre or 10 adult APL/m²,” Ms Micic said.
“Landholders who observed APL on their properties last autumn need to be particularly vigilant, as there are likely to be egg beds hatching now.”
While it is up to landholders to control locusts on their properties, DPIRD officers will be monitoring for APL over spring and summer and providing advice on treatment measures.
