Medium and high density locust swarms have made their way into Victoria.

Swarms have been reported at Charlton, Echuca, St Arnaud, Quambatook and Wycheproof, with some stretching up to 25 kilometres wide.

The Department of Primary Industries fears it could be the worst locust plague in 75 years.

The State Locust Controller, Russell McMurray, says the swarms have the potential to move quickly into other areas.

"They can move up to 50 kilometres in a day, during the day time and up to 700 kilometres at night when they get up into the night area subject to the wind conditions," he said.

"We're certainly requesting that the community be vigilant, if they see swarms to let us know, particularly where those swarms land."

Warm weather is behind the burst in swarms.

There have been almost 11,500 reports to the Locust Hotline, with the DPI fearing it could be the worst plague in 75 years.

Mr McMurray says drivers need to be careful.

"They certainly should slow down if not pull over on the side, turn their headlines on," he said.

"We're encouraging motorists in the region to also ensure that their washer bottle are full and they have detergent in those and that they have some form of meshing over the front of their cars to avoid locusts getting into the radiator and causing the car to overheat."

Mr McMurray is warning vegetable crops could be hard hit.

"In respect to a lot of the crops that are up there, like the barley and wheat, you'll probably find that they've matured to such a point that they won't be as big a target for the locusts as what the lush green vegetables will be, or the pasture," he said.