Agrivision manager Kent Wooding, Swan Hill, said there were large numbers of locusts right throughout the Mallee, tending to pockets of heavy infestations.

“These pockets are changing daily as the locusts move, so there is no one area you can say is impacted more than others,” he said.

Mr Wooding said a predicted cool change on the weekend would hopefully bring some relief from the migrating insects.

“We hope it gets cool enough for them to stop flying. Generally, at around 18 degrees or less, they will not fly.

“It’s meant to be cool for a week following the change, so hopefully that will stop the problem of locusts on the wing.

“Until then, we are recommending most of clients to stop sowing until the change and reassess then. Crucially, it will stop their mobility.”

The insects have already claimed casualties, with the isolated paddocks of canola eaten off, which Mr Wooding said will be unlikely to come back and will need to be resown.

However, Mr Wooding said the insects were generally showing a preference for better developed old-crop cereal volunteers, then for new-crop cereals, which will be better equipped to rebound from the insect grazing.

“The cereals have just had a haircut and will be unlikely to need resowing, but the odd case of canola that’s been nipped off is a different story.

“Overall, seeing as the locusts have generally gone for crop volunteers or cereals, there isn’t too much damage as yet.”

He said farmers needed to record when locusts were laying eggs so they could be prepared for the spring hatch.