KUNMING, July 16 (Xinhua) -- Locust swarms had invaded an area of 8,096 hectares in southwest China's Yunnan Province as of Tuesday, local authorities said Thursday.

The city of Pu'er was worst affected with the swarms seen in 8,018 hectares while Xishuangbanna Dai Autonomous Prefecture saw 78 hectares taken over by the insects, according to the provincial forestry and grassland administration.

Local authorities have used chemical and biological means including spraying pesticides by drones to curb their spread on about 6,938 hectares since the locusts were first found on June 28. Over 31,000 people have also been mobilized.

Experts said the situation is under control, but more locust swarms are expected to migrate into China from outside the border until September, posing additional challenges. Enditem