LOCUST numbers have dropped with no reports of adults in Victoria and low populations found in NSW and Queensland.

The latest Department of Agriculture, Fisheries and Forestry Locust Bulletin states locust populations are in decline across the country.

There were reports of high density adults and swarms in the northeast region of SA, in the Peterborough, Burra, Spalding and Jamestown areas.

Some swarm egg laying is believed to have occurred during late December and heavy rain had made suitable conditions for nymphal survival.

The region can expect to see a decline in adult densities this month with a summer generation of nymphs in localised areas and the possibility of some hopper band activity.

"There were very few reports of locust activity in Victoria and southern South Australia, indicating a decline in population level," the report reads.

In NSW adult numbers remained very low in the Central West, Darling and Riverina Livestock Health and Pest Authority areas while some scattered adults were reported in the Western LHPA.

Southwest Queensland had low density adult populations and very few nymphs.

In Victoria the spring nymph generation was localised to the southern Wimmera and Grampians districts and may contribute to the adult population in January but the probability of a serious infestation is very low, the report says.