Deadly hornets kill 41 people in China, injure over 1,500

By Madison Park and Dayu Zhang, CNN

October 3, 2013 -- Updated 0620 GMT (1420 HKT)

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A patient of a hornet attack shows stings left in his arm from his hospital bed

STORY HIGHLIGHTS

• Hornet stings kill 41 people and injure 1,675 people since July
• Shaanxi province sees unusual level of hornet activity, dry weather, human moves are factors
• People who have been stung dying from allergic reactions or multiple organ failure
• Type of hornest also a threat to honey bees, often seen in Japan

Hong Kong (CNN) -- Swarms of aggressive hornets, in their fall mating season, are inflicting a deadly toll in a central Chinese province.

Hornets have killed 41 people and injured 1,675 people in three cities in Shaanxi province since July, according to the local government. Thirty-seven patients remain in critical or serious condition.

Over the summer and early fall, giant hornets have invaded schools full of children and descended upon unsuspecting farm workers.

One of them is Mu Conghui, a woman who was attacked in Ankang City while looking after her millet crop.

"The hornets were horrifying," she told Xinhua, the Chinese state-run news agency. "They hit right at my head and covered my legs. All of a sudden I was stung and I couldn't move.

"Even now, my legs are covered with sting holes."

Two months, 13 dialysis treatments and 200 stitches later, Mu still remains hospitalized and unable to move her legs.

In central China, 37 patients remain in critical or serious condition after hornet attacks.

The influx of venom to the human body can cause allergic reactions and multiple organ failure leading to death. Patients like Mu have been receiving dialysis to remove the toxins from her body. In photos, patients bore deep dark craters scattered across their limbs, the size of bullet wounds.

Government authorities say these attacks are from a particularly venomous species, the world's largest hornet, known as the Asian giant hornet or vespa mandarinia.

The giant hornet extends about 3.5 to 3.9 centimeters in length, roughly the size of a human thumb. It has an orange head with a black tooth used for burrowing, according to an animal database at the University of Michigan.

Dr. Wang Xue, director of the intensive care unit at First Affiliated Hospital of Xi'an Jiaotong University and an expert of the provincial hornet sting treatment guidance unit, warned in a Shaanxi government release that hornets tend to be aggressive and more active during September and October -- their breeding season. The hornets do not go into hibernation until December, according to local government authorities.

Local authorities have deployed thousands of police officers and locals to destroy the hives. So far, about 710 hives have been removed and at least 7 million yuan (about $1.1 million U.S.) sent to areas affected by hornets, according to a government press release.

The spate of attacks could be caused by the unusually dry weather in the area, authorities say. The arid environment makes it easier for hornets to breed. Urbanization could also be a contributing factor, as humans move into hornets' habitats.

People can inadvertently irritate the hornet hives, as most are tucked away in secluded places, such as tree hollows or even underground.

The Asian killer hornet, also known as Vespa mandarinia, is the world's largest hornet.

The provincial government has warned residents to wear long sleeves when outdoors, and not to attempt driving away the swarms or removing their hives.

Vespa mandarinia are known as formidable, carnivorous killers, found in eastern and southeastern Asia, especially in Japan. About 30 to 50 deaths are reported each year in Japan from such attacks, according to Japanese studies.

The species is also destructive to western honey bees. Research in Japan suggests tens of thousands of honey bee hives are damaged by the giant hornets each year.

The species feed their young with the larvae of other insects and use their mandibles to sever the limbs and heads of their prey. The hornet's venom sting is a neurotoxin so powerful that it dissolves human tissue, according to the Guinness Book of World Records.

The giant hornets are attracted to bright colors, human sweat, alcohol and sweet flavors and smells. They are especially sensitive to when animals or people run, according to Xinhua.

One victim told local media earlier this month that "the more you run, the more they want to chase you." Some victims described being chased about 200 meters (656 feet) by a swarm.

Every breeding season, the giant hornets produce an average of 10,000 offspring. They feast on other insects such as beetles, wasps and bees, launching coordinated attacks on the hives of their prey.