LOCUSTS can still pose a threat to emerging crops despite the cooler weather, Victoria's locust commissioner Gordon Berg has warned.

He said flying and swarming locusts could damage newly sown crops this autumn.

Mr Berg said it was not recommended to spray adult locusts as it was far more efficient to spray hoppers when they were on the ground.

"However, landholders may make a business decision to spray to protect valuable crops," Mr Berg said.

Landholders can claim a rebate for the cost of chemicals if they are eligible.

The rebate is available for spraying carried out between September 1 last year and before May 31 this year.

To claim the rebate, landholders need to submit an application form to the Department of Primary Industries by June 30.