By Huang Zhiling, China Daily

CHENGDU: Swarms of hornets in Southwest China have killed at least 10 in a plague experts say may have been brought by the overuse of pesticides.

A teacher at the Chengdu Sports Institute in Sichuan Province, Deng Sheng, still winces at the memory of being attacked in Suining, a city in southern Sichuan, last Saturday.

As he parked his car, the vehicle hit a tree, apparently angering a swarm of the 3 centimetre-long insects which descended on Deng.

"I was so scared that I got back in the car straight away. But I had already been stung on the head," he said.

In excruciating pain, Deng rushed to the nearby Suining Municipal People's Hospital, where he was shocked to learn that more than 10 people in the area have died from hornet stings this year.

Wang Haijun, a young farmer in Chuanshan District of Suining, is still in hospital after being stung by hornets last Wednesday.

"I bumped into a tree and suddenly countless hornets poured down and chased me as I was trying to run home. I fainted by the door," he recalled.

Wang's sister believes the hornets treated her brother as their enemy, adding that they did not fly away until he fainted and lay motionlessly on the ground.

Zhao Dechun, chief of the Internal Department of Suining Municipal People's Hospital, said he was surprised by the recent spate of hornet attacks. In the past month, his hospital has treated 25 hornet sting victims, he said.

According to Pu Zhengrong, an official with the Suining Fire Department, his team has received nearly 70 calls asking for help to remove hornets' nests. "Each time after we receive a call, we get rid of several nests," he said.

"Because it is such a serious problem, our team set up a seven-member group to get rid of hornets' nests in July," he said.

Experts say hornets do not normally attack people. However, overuse of pesticides, eliminating hornets' natural enemies, could be responsible for an explosion in the hornet population.

In autumn, when people disturb hornets by picking fruit or collecting medicinal herbs, the insects may regard them as a threat, prompting an attack, said Fei Lisong, a zoologist at Chengdu Zoo.