Swarms of Asian giant hornets have killed 42 people in northwestern China in recent months, state media said Thursday, as temperatures rise and development drives the stinging insects into cities.
The terrifying attacks by the world's largest hornets started in July, the official Xinhua news agency said Thursday, with 1,640 people having been stung.
Of those, 206 are being treated in hospitals, it quoted the National Health and Family Planning Commission as saying. At least 37 people are believed to be in critical or serious condition.
The Asian giant hornet injects a highly toxic venom when it stings, releasing eight different chemicals into the victim's body. Each chemical serves a different purpose, and can cause tissue degeneration, anaphylactic shock and renal failure.
"With the development of air-conditioning, urban landscaping and residential environment, hornets have started to migrate and relocate to cities, which has increased the probability of their hurting people," Xinhua reported.
Huang Rongyao — a senior official concerned with pest control in the city of Ankang, which has borne the brunt of the attacks — attributed the phenomenon to warmer-than-usual temperatures in the region.
"Furthermore, hornets are sensitive to bright colors, the smell of human sweat, alcohol, perfume, any specially scented articles and things that are sweet as well as the running of humans or animals," Huang said.
Hua Baozhen, a professor of entomology at Northwest Agriculture Forestry University, attributed the attacks mostly to a decrease in the number of the hornets' natural enemies, such as spiders and birds, due to ecological changes.
The attacks were centered on the cities of Ankang, Hanzhong and Shangluo, the Shaanxi Daily reported.
The provincial forestry department sent three teams to raise public awareness of hornets in the Shaanxi province where the attacks have been taking place, said CNWEST, the government-run news portal of the province.
It also said that the province allocated six million yuan ($980,000) for work to prevent attacks and treat victims in the three cities.
Xinhua described the hornets as about the size of an adult thumb.
China News quoted a person working to combat them as saying they are about three to four centimeters (less than two inches) long and thousands can inhabit a single hive.
As their stingers do not have barbs, they remain attached when the hornets attack, allowing them to sting the same victim multiple times. The hornets are fast, and are able to travel up to 62 miles at 24 miles per hour, much faster than the average person's running speed.
Chinese officials say they have removed more than 300 hornet nests from residential areas in affected areas since July. A director of the Ankang Disease Control Center said swarms of the flying bugs are common in the area every fall.
The provincial government said hornets are most aggressive in behavior when they mate and migrate in September and October.