"The Mosquito Solution" by Michael Specter

A few weeks ago, I found myself standing in a dank, fetid laboratory at Moscamed, an insect-research facility in the Brazilian city of Juazeiro, which has one of the highest dengue rates in the world.

A plastic container about the size of an espresso cup sat on a bench in front of me, and it was filled with what looked like black tapioca: a granular, glutinous mass containing a million eggs from Oxitec’s engineered mosquito.

The goal is both simple and audacious: to overwhelm the native population of Aedes aegypti and wipe them out, along with the diseases they carry.

“This is not a panacea,” Giovanini Coelho, who coordinates the Brazilian Ministry of Health’s National Program for Control of Dengue, told me.

Despite the experiment’s scientific promise, many people regard the tiny insect as a harbinger of a world where animals are built by nameless scientists, nurtured in beakers, then set loose—with consequences, no matter how noble the intention, that are impossible to anticipate or control.

Like most other pathogens, the viruses and parasites borne by mosquitoes evolve rapidly to resist pesticides and drugs.

Reiter, a professor of medical entomology at the Pasteur Institute, in Paris, is one of the world’s experts on the natural history of mosquito-borne diseases.

Dengue has always been considered a tropical illness. But its mode of transport, the mosquito, rarely lives more than a hundred yards from the vector’s principal source of sustenance—us—and as our demographics have changed so have those of the mosquito.

Males are fed sugar; females, first lured by the smell of human sweat, feed on goat’s blood obtained weekly from a nearby abattoir.

Alphey, who knew little about the field, began to think about how to supplant radiation with the practices of modern molecular biology.

His goal was not exactly to sterilize the males but to alter their genes so that any progeny would die.

It was only a test of feasibility; no one knew how it might affect the local ecology or whether it would actually reduce the incidence of dengue.

Doyle wanted to lower the risk of a dengue outbreak in Key West, but the district was already spending more than a million dollars a year on insecticide, and he was loath to dump more chemicals in people’s yards.

Many biologists argue that if Aedes aegypti, or, indeed, all mosquitoes, were to disappear, the world wouldn’t miss them, and other insects would quickly fill their ecological niche—if they have one.

“More than most other living things, the mosquito is a self-serving creature,” Andrew Spielman has written. “She doesn’t aerate the soil, like ants and worms. She is not an important pollinator of plants, like the bee. She does not even serve as an essential food item for some other animal. She has no ‘purpose’ other than to perpetuate her species..."

In a lengthy letter to government regulators in Malaysia, she stressed that there could be ancillary impacts “if the mosquitoes are eliminated altogether.” For instance, what would happen to those fish, frogs, other insects, and arthropods that feed on larval or adult mosquitoes?

Hoffman has assiduously followed the Oxitec experiments.

To the consternation of many, Oxitec recently applied to the F.D.A. for approval of its mosquito.

The meeting quickly became emotional and, at times, rancorous.

“The Oxitec approach is safer and more environmentally benign,” Reiter said. “If the phrase ‘genetically modified’ was not attached, I don’t think people would even mind.”