The mosquito holds still and then begins to suck; in 90 seconds’ time, she feels full, and stops. In the entire animal kingdom, the mosquito occupies a special place as receptacle for our hatred and disgust.
Even the great and generous EO Wilson, author of the touchstone argument for preserving biodiversity, The Creation: An Appeal to Save Life on Earth, makes an exception for anopheles Gambia, which spreads malaria in Africa. Where we revere and anthropomorphize such brutal predators as sharks, tigers and bears, we view these tiny ectoparasites as worthless, an evolutionary accident with no redeeming or adorable characteristics.
Today, according to the Gates foundation, the diseases they carry kill about 725,000 people a year, 600,000 of them victims of malaria. This deadly work is carried out all over the planet: mosquitoes are found on every continent except Antarctica.
In reality, as Lindsay and Ransom are quick to point out, the total extinction of all mosquito species would be as senseless as it would be impossible. Of the 3,000 varieties on the planet, only 200 or so bite us; only Andes Egypt, and perhaps the more common Rule quinquefasciatus, are thought to carry Zika.
“ We’ve got wonderful new weapons,” says Dr Jo Lines, reader of malaria control and vector biology at the London School of Hygiene and Tropical Medicine. For Lines, there is a more pressing case for the eradication of Egypt, as a carrier of dengue fever, than any other species of mosquito.
“Otherwise this is going to go on for a thousand years.” He points out that because Egypt are thoroughly adapted to a man-made environment, unlike the anopheles variety that carry malaria, they will only become more prevalent as the human population and its accompanying urban sprawl grow. For the specified advocates, the most promising means of attack lies in a cutting-edge technology known as a gene drive, the subject of much excited reporting in recent weeks.
And no wonder, so seductively dystopian is its premise: that a species can be eradicated by altering the genetic code of males in captivity so that they will only be able to produce sterile offspring, then releasing them into the wild to mate with unsuspecting females, rendering the next generation barren. Oxide, a British company that has pioneered this kind of genetic modification, has been conducting trials since 2009, and has a production facility in Campinas, Brazil.
“ We are able to modify the gene with unprecedented precision and flexibility.” Chianti, a leading expert in the field, has focused his own work on a similar mechanism that fights the malaria-carrying Anopheles Gambia, but he says that it could be exported to other species as well. So it is totally reversible.” He gives a small laugh, and sounds freshly amazed at the power of the technology at his fingertips.
For others, the attention-grabbing qualities of a genetically modified mosquito spreading its poisoned seed are a source of more frustration than wonder; a distraction from on-the-ground efforts that could make a substantial difference in the fight against Zika and dengue fever right away. “Everyone talks about vaccines and GM, but actually pecan control this vector by much simpler means.” Lindsay points out that Egypt were eliminated from much of South America in the 1960s by the simple mechanism of spraying containers with oil, kerosene and, later, the controversial pesticide DDT.
This thing breeds in small containers: flowerpots, gutters, tires, water bottles. That’s not something for health professionals: that’s about educating and empowering communities so that they can reduce the risk themselves.” So vexed is Lindsay by the way this crucial message is, in his view, being drowned out, that he and a group of colleagues has written a letter to the Lancet, shortly to be published, urging a renewed focus on these less exotic measures.
And it’s very, very difficult to get funding to support research-capacity development.” Read the deadly last three words of that quote, and you will see exactly where the problem lies. Photograph: Marvin Regions/AFP/Getty Images It is hard to prove a direct causal link between the exoticism enthusiasm for wiping out a species on the one hand and the underfunding of such crucial work on the other.
All the same, there is a certain bitter irony that in an attempt to beat a disease whose impact will be felt most keenly by women and their unborn children, and which has been exacerbated by a shortage of funding for studies that would focus on the wellbeing of women in developing countries, we are contemplating a macho solution that entails sending male mosquitoes to impregnate as many females as possible, with the ultimate ambition of wiping the enemy off the face of the Earth. Whatever the priorities, no scientist disputes that if the technology were to be perfected, the gene-drive plan would be a remarkable boon to public health.
Yet there may be other, more abstract, objections contained in the eerie idea of that word: extinction, the permanent eradication of a species that has evolved and survived for thousands of years. Melanie Challenger, author of On Extinction: How We Became Estranged from Nature, travelled from England to South America to the Antarctic to think about how we contend with the elimination of the species.
In the end, if the technical and ecological objections can be overcome, it seems unlikely that philosophical arguments for the sanctity of Andes Egypt will hold sway. In his book, The Edge of Extinction, he considers how different cultures deal with the loss of species and habitats that surround them.
“I don't think it's realistic because there is going to be no silver bullet that is going to eradicate them all,” said Joseph M. Colon, the technical Advisor American Mosquito Control Association and an entomologist with the Navy for 20 years. Rich Merritt, an emeritus professor at Michigan State University who has worked with mosquitos for 25 years, agreed, but for very different reasons.
“A small minority of the species play a serious role in transmitting the pathogens that cause diseases in humans, so it makes perfect sense from a public health standpoint to devise ways to keep those mosquitoes from biting people,” said Dan Stricken, a senior program officer at the Bill & Melinda Gates Foundation. “ Support for this approach has gained traction of late, partly due to the success of several innovative control methods.
By introducing the bacterium into the Andes Egypt population, it protects the mosquito from contracting dengue, Zika, and other viruses and thus from spreading it onto their unsuspecting human host. An experimental program led by Google parent Alphabet Inc. to wipe out disease-causing mosquitoes succeeded in nearly eliminating them from three test sites in California’s Central Valley.
The effort appears to be paying off, according to a paper published in the journal Nature Biotechnology on Monday. Bradley White, the lead scientist on the Debug initiative, said mosquito-suppression is even more important during the pandemic, so that outbreaks of mosquito-borne diseases such as dengue fever don’t further overwhelm hospitals.
The insects are bred in Verily labs to be infected with a common bacterium called Wolbachia. In most collections, per night Verily found one or zero female mosquitoes in each trap designed to monitor the population.
“ We had a vision of what this should look like, and we managed to do that pretty perfectly,” said Jacob Crawford, a senior scientist on the Debug project. But in the hot, humid regions of the tropics and subtropics, diseases caused by the Andes Egypt, such as dengue fever, Zika virus and chikungunya, kill tens of thousands of people every year.
Microsoft Corp. co-Founder Bill Gates has pledged more than $1 billion to help wipe out malaria, including controversial efforts to genetically modify mosquitoes. The following year, Verily stepped in, bringing more advanced technology to the breeding and release process that could make it possible to expand such efforts to entire cities or regions.
“Once you try to start rearing hundreds of thousands of mosquitoes a week, you run into all sorts of problems,” said White. © Bloomberg Google Has A Plan To Eliminate Mosquitoes Around The World Verily has expanded its partnerships to include Singapore’s National Environment Agency.
In early November, the Environmental Protection Agency (EPA) granted commercial approval for the company MosquitoMate to release its special male Andes albopictus mosquitoes, called ZAP mosquitoes, in 20 states and Washington DC. Those offspring never actually hatch, however, because the Wolbachia interferes with the mosquitoes parental chromosomes, causing the eggs to not develop.
So far, MosquitoMate trials in Kentucky, California and New York have shown that the ZAP mosquitoes can reduce the overall mosquito population of a given release area by more than 80%. Stephen Dobson, the CEO of MosquitoMate and a professor and medical entomologist at the University of Kentucky, says he’s been working on the Wolbachia-carrying mosquitoes for about 20 years.
The EPA has given commercial approval for Mosquitoes’s Andes albopictus ZAP mosquitoes for five years. Mosquitoes are unlovely creatures, all twitchy legged and whining, their larvae infesting miasmas and dismal swamps.
Juvenile mosquitoes are also important in some freshwater food webs, including as prey to specialists such as the mosquito fish, Gambia Afghanis or in the tiny pools of water held in the leaf bases of pitcher plants and bromeliads high in the rain forest canopy. In among the canopy trees a miniature fauna of vividly colored poison dart frogs and crabs thrive in the bromeliad pools, called phytotelmata, feeding off the bodies of drowned juvenile mosquitoes.
But despite poison dart frogs and bats having their own fan club among ecologists and nature enthusiasts, they are unlikely to sway the majority of people in favor of mosquitoes. The second argument is that mosquitoes have a more general role providing ecosystem services such as pollination by adults or driving the release of nutrients as their young feed on organic detritus.
While the decline of the honey bee is a prominent example of an ecosystem service at peril, mosquitoes are just another one of the much pollination bit-part players, an unloved understudy that can be written out. God has placed a striking angel with a flaming sword of deadly fevers, who prevents us from penetrating into the interior to the springs of this garden.