Forest protectors spray pesticide in Jinyun Mountain nature reserve of Chongqing, southwestern China on Friday, August 3, 2007. [Photo: Chongqing Economic Times]

Forest protection officials in southwest China are using a special "pesticide" mix featuring human urine to kill locusts which plague nearly one third of a special bamboo forest.

Since late April, the pests have attacked more than 130 hectares of bamboo in Jinyun Mountain nature reserve in Chongqing municipality and last month their numbers exploded, the Chongqing Economic Times reported on Saturday.

The best pesticide is a blend of urine and Dylox, and the reserve's administration office has distributed buckets to five forest protection stations to collect urine, an administration staff told the newspaper.

Pesticide is usually sprayed every spring to tackle grasshoppers while they breed, but recent heavy downpours and flooding in the region washed all the pesticide away.

The administration office recently sent 20 workers to use powder on the bamboo leaves but this has proved ineffective.

Although some of the pests are larvae, they have tremendous appetites and people have reported hearing the rustling sound of grasshoppers chewing bamboo leaves at night.

It was estimated there are more than ten grasshoppers per square metre in the bamboo forest.