Brazil and Argentina are monitoring the movements of a large swarm of locusts, which have been eating their way through crops in the region.
The insects, which can cover a distance of 150km (93 miles) in a day, have already travelled from Paraguay to Argentina and it is feared Brazil and Uruguay could be next. Brazil has told farmers to be alert to the possible arrival of the locusts.
Kenya and India are also currently fighting locust swarms.
The swarm originated in Paraguay and crossed into Argentina on 21 May.
The insects have already moved through the Argentine provinces of Santa Fé and Formosa, where they caused damage to crops of corn, sugar cane, wheat and oats.