Millions of locust are now about 100 kilometers (62 miles) from the Rio Grande do Sul state border.
But wind currents on Wednesday may take the insects into Brazil, Celso Oliveira, a meteorologist at Somar Meteorologia in São Paulo, said by text.
The swarm could harm wheat, canola and barley crops in the western part of the state, as well as native vegetation, he said.
In late June, Brazil’s Agriculture Ministry declared a state of emergency in two southern states to allow officials to take precautions.
The locusts have remained in Argentine territory since then, after arriving from Paraguay in May. A second cloud is in Paraguay, about 300 kilometers from the border, Argentine officials said Thursday.
And according to the following videos, the locusts seem to move towards north and start invading countries like Colombia:
Massive swarms of locusts have ravaged fields in Africa and Pakistan, destroying crops and dealing a crippling blow to economies.
Locusts are migratory, able to travel as many as 150 kilometres in a day. They have been known to cross from one province to another, or even from one country to another, in a few hours.