After a year of battling drought, fire, dust, flood and disease, farmers in far western New South Wales are now facing a plague locust infestation.

Key points: Landholders are being asked to catch and take photos to identify the locusts to help in its control

Landholders are being asked to catch and take photos to identify the locusts to help in its control The Australian plague locust damages pastures and crops and mostly occurs in central western parts of NSW

The Australian plague locust damages pastures and crops and mostly occurs in central western parts of NSW Plague locusts lay dormant during poor seasons and crop up in bumper ones

The Australian plague locust species, if not controlled, can cause significant damage to crops and pastures by consuming all in their path.

Landholders are being asked to report locust activity to Local Land Services to help biosecurity experts stop the destructive insects from spreading.

Senior biosecurity officer Robynne Wells-Budde, from Cobar, is urging the public to keep samples.

"I've been asking people them to catch a few, take pictures and send them through to me so I could identify them," Ms Wells-Budde said.

She said her usual biosecurity work had been disrupted due to the ongoing coronavirus crisis.

"I have been asking people to put their 'hoppers' in the freezer and put them in their letterboxes for me to collect," she said.

Landowners are being asked to look out for signs locusts have been "test-drilling", which is when a female locust drills a hole into the ground to lay eggs. Signs of drill holes don't always mean locusts have laid eggs; they can be testing the potential the soil has as an egg bed."

"We are finding that some of them are starting to mate, so now we just want landholders to monitor where they are, give us a GPS coordinate, let us know if they are test-drilling or if they've got eggs on board," she said.

"These plagues can be very problematic in the spring when they start to hatch out if we haven't got a good handle on where they've come from."

In the coming weeks biosecurity staff will be inspecting properties around Balranald, Hillston, Bourke, Brewarrina and Broken Hill.

A number of low-density locust plagues have been identified in Cobar in western NSW, but these plagues must be closely monitored because each locust can lay 50 to 70 eggs. ( Supplied: NSW DPI )

Stopping the spread

Plague locusts lay dormant during poor seasons and crop up in bumper ones.

In western NSW, the last serious plague incident occurred in 2015 around the towns of Warren, Albert and Gilgandra.

Ms Wells-Budde said while the current numbers of locusts were low-density, she was wary because each insect could lay up to 70 eggs.

"Even a low-density swarm has the potential to grow into something much bigger," she said.

"That's why we need people to start monitoring, so we know where they are and can get on top of them as quickly as possible."

She said locusts normally hatch out in the spring.

Usually the insects hatch en masse in the channel country in Queensland then migrate down into New South Wales, Victoria and into South Australia.