LOCUST swarms are expected through Victoria's North East and the Wimmera by the end of this week.

Department of Primary Industries locust controller John Balfour said swarms could be expected in all areas where there were locusts.

"We expect true swarming behaviour by the end of the week," Mr Balfour said.

However, he said there were some hoppers on the ground that would be susceptible to spraying.

Aerial surveillance at the weekend showed 56 bands of hoppers near the Grampians, south of Ararat and northeast of Casterton, and around Balmoral.

The locusts are being spurred on by warmer temperatures.