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 42
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, hornets have invaded schools full of children and descended upon
unsuspecting farm workers in China.
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.
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.
Some experts cited in
Xinhua stated additional factors such as increased vegetation and a
decrease in the hornets' enemies, such as spiders and birds because of ecological changes.
Humans can inadvertently
irritate the hornet hives, as most are tucked away in secluded places,
such as tree hollows or even underground.
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. Most of the deaths are due to allergies to the venom, said
Shunichi Makino, director general of the Hokkaido Research Center for
Forestry and Forest Products Research Institute.
"It's very difficult to prevent the attacks because hornet nests are usually in hidden sites," he said.
Makino, who specializes
in entomology, warned that the sting from an Asian giant hornet was
severe compared with those of other insects.
"The venom of an Asian
giant hornet is very special compared with other hornets or yellow
jackets," he said. "The neurotoxin -- especially to mammals including
humans -- it's a special brand of venom."
The giant hornets are
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 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 wasps and bees, launching coordinated attacks on
the hives of their prey.
