Death toll from giant hornets rises in Shaanxi; is warming to blame?

Giant hornets are plaguing Shaanxi, but despite patrols to trace their nests and destroy them, the number of people being stung to death is still rising

PUBLISHED : Monday, 07 October, 2013, 12:00am
UPDATED : Monday, 07 October, 2013, 7:25am

Chen, a farmer, pointed with a shaky hand at the small plot of cabbage, spring onions and corn where his friend Yu Yihong was stung to death by giant hornets.

"When he got to the hospital, there were still two hornets in his trousers," said Chen, who declined to give his full name.

"The hornets' poison was too strong - his liver and kidneys failed and he couldn't urinate."

Yu, a square-jawed 40-year-old farmer in perfect health, had been harvesting his crops when he stepped on a nest of Vespa mandarinia hornets hidden under a pile of dry corn husks.

The hornets swarmed all over him, stinging him through his long-sleeved shirt and trousers.

He ran, but the hornets chased him, continuing to sting his arms, legs, head and neck.

About 50 friends and relatives gathered outside his mountainside home in Yuanba village to mourn his death. Yu's wife and two children sat inside, weeping.

Vespa mandarinia is the world's largest hornet, about the size of a human adult's thumb.

It is yellow and black and highly venomous. Its 6mm-long stingers carry a venom potent enough to dissolve human tissue.

Victims may die of kidney failure or anaphylactic shock.

Yu's story is a tragic but increasingly common one in Shaanxi province where, over the past three months alone, hornets have killed 42 people and injured a further 1,675.

Ankang, a municipality in the province's south, appears to be the epicentre of the scourge.

While hornets infest its mountainous rural areas every year - 36 residents were stung to death between 2002 and 2005 - locals and municipal officials say this year is close to an epidemic, the worst they have ever seen.

At least some of the deaths were caused by Vespa mandarinia, or the Asian giant hornet, experts say. The species does not typically attack unless it feels its nest is threatened.

But when it does, it can be fierce and fast - the hornets can fly at 40km/h and cover 80 kilometres in a day. They nest in tree stumps or underground, making nests very difficult to detect.

Both locals in the northwestern province and experts blame this year's scourge on climate change - the past year has been unusually warm, allowing a high number of hornets to survive the winter. Huang Ronghui, an official at the Ankang Forestry Bureau's pest control department said the hornets may have been agitated by a dry spell, while labourers had moved deeper and deeper into the mountains, disturbing their nests.

"Other than this, hornets are attracted to bright colours and the smell of peoples' sweat, alcohol and sweet things," he said. "They're sensitive to movement, such as running people or animals."

The region has also been overrun by the Asian hornet Vespa velutina, a slightly smaller species which can be equally dangerous. Hundreds, even thousands, inhabit their nests, which hang from high places.

In Chengxing village, a few miles down a winding mountain road from Yu's hometown, 16-year-old Tan Xingjian points at a tree in the distance.

Hanging from one thick branch was a pale, basketball-sized bulb, its surface alive with darting black specks. "That's where they live," Tan said. "We don't dare to go near there."

Ankang is on alert, with the authorities posting warning notices online, on roadside tree trunks and on primary school walls. The crisis has exhausted Gong Zhenghong, the mayor of Hongshan township in rural Ankang. Since September, Gong has spent nearly every night wandering the township exterminating nests with four other cadres.

He said there were 248 hornet nests in Hongshan, with 175 of them close to schools and roads.

Gong and his team survey nests by day. Then, once the sun sets, they dress in homemade anti-hornet suits made of rain jackets and canvass and burn the nests with spray-can flamethrowers. "They don't fly around at night," he said.

Sometimes, his team begins work in the late evening and doesn't finish until 2am. "We'd normally send the fire squad to do this, but this year there were too many nests," he added.

Gong left his office, returned with a black rubbish bag, and pulled out the charred remains of a nest, the blackened tails of bulb-like larvae protruding from its combs.

Two other cities in Shaanxi - Hanzhong and Shangluo - have also been besieged by hornets, though the death tolls have been markedly lower.

In the Guangxi Zhuang autonomous region in the southwest, a swarm of hornets attacked a primary school last month, injuring 23 children and seven adults. The teacher, Li Zhiqiang, told pupils to hide under their desks and tried to fight off the creatures until he lost consciousness, state media reported.

The hornets are everywhere in Ankang. In Liushui township, a scattering of two-storey concrete homes sandwiched between a lush hillside and a stagnant river, an elderly shopkeeper in a purple blazer said the hornets had infested a cabbage patch near her home.

"The government has been coming down and burning them, but they can't burn them all," she added, pointing down into the brush. "I'm not willing to go down there."

Mu Conghui, a 55-year-old Ankang villager, was stung 200 times while tending her rice field in August. "The hornets are terrifying - they flew at my head and stung me so much that I couldn't move," she said.

"My legs were crawling with hornets. Right now my legs are covered with small sting holes - over the past two months I've received 13 dialysis treatments."

The Ankang government said it had removed 710 hives and sent seven million yuan (HK$8.8 million) to help affected areas.

Deng Xianghong, deputy head of the Ankang propaganda department, said: "We're doing everything we can, but there's only so much we can do. God has been unfair to us."


Potent Killer

Name: Vespa mandarinia, or the Asian giant hornet

Habitat: Temperate and tropical East Asia

Size: Adults can grow up to 4.5cm long, queens 5.5cm, five times the size and 20 times the weight of a honey bee

Prey: Other large insects such as bees and other hornet species and mantises

Sting: 6mm long and able to inject a large amount of potent venom

Venom: Can cause kidney and liver failure if not treated fast enough. Typically, the species causes about 40 deaths every year

Food: Sometimes eaten, raw or fried, in Japan. Asian and European manufacturers have begun to market dietary supplements and energy drinks using synthetic versions of the hornet's larval amino acid secretion as "hornet juice", touting claims about improved endurance