China Seeks to Legislate Extinction of Mosquitoes

Yellow fever is a viral haemorrhagic disease transmitted mainly by the same species of mos
AFP

China’s rubber-stamp legislature, the National People’s Congress (NPC), on Tuesday entertained a proposal to completely eradicate mosquitoes.

The proposal was swatted down by China’s National Health Commission, which pointed out that killing every mosquito in China was not feasible.

The health commission noted that “research on innovative mosquito control techniques remains relatively weak” even after decades of effort.

These observations apparently did not occur to the NPC deputies who signed the mosquito genocide proposal, or perhaps they were just looking for an easy way to cadge some support from the anti-mosquito segment of the population.

The South China Morning Post (SCMP) reported that a Chinese website held an online survey of the mosquito-killing proposal and racked up 40,000 votes in about five hours. Pro-mosquito voters put up a surprisingly strong showing:

About 57 per cent of the respondents supported the proposal, saying that wiping mosquitoes out is necessary as they are “likely to transmit diseases”. About 40 per cent argued it was not a good idea because the “creatures exist for a reason”.

“I totally agree to kill all the mosquitoes. They are really irritating,” read one post on Weibo, a Twitter-like social media platform. “Maybe someday they will carry unknown diseases as complicated as the coronavirus!”

Many commenters suggested the idea was shortsighted. “Have the deputies ever considered the biological chain? Once the balance is broken, consequences could be huge,” wrote one Weibo user. “I doubt if human beings can defeat mosquitoes. Even if technologies allow us to do so, we have to measure the economic, social and environmental costs first”, wrote another user. Other people questioned the priorities of NPC deputies. “We are suffering from stringent Covid-19 control measures. Why no proposal to change that?” wrote a commentator.

Mosquitoes are indeed likely to transmit diseases, including encephalitis, malaria, and the pandemic of yesteryear that was completely upstaged by Chinese coronavirus, the Zika virus. Most strategies to control Zika involved killing the aedes aegypti mosquitoes that carry it, including some innovative ideas to effectively neuter the mosquito with genetically-modified sterile breeding stock.

The Chinese commentators who are worried about the ecological effect of wiping out all mosquitoes have some support from biologists, who point out that mosquitoes are annoying and often dangerous to humans, but they are also a valuable food source for many species of fish, birds, lizards, frogs, and others. 

The safest compromise approach appears to be slowing the growth of the most dangerous disease-carrying mosquito populations, and the safest means of doing that involves tricking male mosquitoes into wasting their time with sterilized female saboteurs. In one Chinese experiment described by the SCMP, such techniques reduced the population of a certain mosquito species on targeted islands by 94 percent.

Another experiment conducted in Brazil from 2013 to 2015 went unexpectedly awry because the mosquitoes were so fecund, and young mosquitoes clung to life with such tenacity, that genetic modifications began spreading through mosquito swarms instead of dying off as planned. Researchers terminated the project because they feared losing control of the modified genetic code that was supposed to sterilize only part of the mosquito population, and they were nervous about how that code might mutate and begin affecting mosquito predators. One of the nightmare scenarios pondered by the scientists was inadvertently creating breeds of mosquitoes that were highly resistant to pesticides.

Having rejected the proposal to work on a method for eradicating all mosquitoes in China, the National Health Commission recommended stepping up traditional control techniques instead, such as cleaning up the trash, waste, and fetid waters that help mosquitoes to breed.

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