A rare leafhopper insect plague in Argentina has knocked an estimated $1.3 billion off the expected 2023/24 corn crop, the director of economic studies at the Rosario grains exchange said on Thursday, after the body sharply cut it harvest outlook, Reuters reported. 

Argentina, the world's No. 3 corn exporter, was headed for a potentially record crop until the outbreak of the pests, which spread a stunt disease that damages corn. That led the Rosario exchange last week to knock 6.5 million tons off its forecast.

"At the moment, the losses caused by the leafhopper are estimated at around $1.268 billion," Julio Calzada, head of the Rosario exchange's economic studies department, told Reuters. The body currently estimates a crop of 50.5 million tons.

The rival Buenos Aires grains exchange has already dropped its corn forecast to 49.5 million tons. The Rosario exchange is likely to cut its outlook further as the disease persists.

The leafhopper insect is a vector of the spiroplasma bacteria and other diseases that damage corn.