BEIJING (Reuters) - China's agriculture ministry said on Wednesday it had now found fall armyworm in 19 provinces, across 5 million mu or about 333,000 hectares of crops.
The situation around the prevention and control of the pest remained severe, the ministry added.
Beijing has previously said the pest, which can infest and damage hundreds of hectares of crops overnight, was a serious threat to China's food security.
China has recommended 25 pesticides for emergency use against the armyworm, part of its efforts to prevent the spread of the destructive pest.
"We haven't found armyworms in our fields yet but have started spraying pesticide on the crops today to prevent against their invading," said Song Quanyong, who grows more than 200 mu of corn in China's central province of Henan.
The fall armyworm reached some parts of Henan province in early May after it was first detected in China's southwestern province of Yunnan in early January, more than 2,500 km away.
"People aren't nervous as many farmers are not aware of the worm yet. And as long as we apply pesticides, our crops will be fine," Song said.
The pest was expected to reach China's northeastern corn region in June or July, according to an expert with a government think tank.
(Reporting by Dominique Patton and Hallie Gu; Editing by Himani Sarkar and David Evans)