Over 300 hectares of crops, particularly tobacco and corn, in northern mountainous Cao Bang province have been damaged by locusts so far this year.

The insects have formed swarms with a density of 100-200 individuals per square metre, and in some places, there are up to about 3,000 hoppers gathering on a square metre.

Hoang Thuy Ngan, deputy head of the provincial Plant Protection Department, said the branch has to date sprayed pesticide over 280 out of 300 hectares of affected areas.

The official recommended local farmers to watch their fields closely and urgently notify the authority if the locusts return.

This is the third consecutive year Cao Bang has been hit by locust infestation.-VNA