We must consider consequences of killing mosquitos

Mosquitoes are one of a few irritations we put up with in order to enjoy the many perks of life in the outdoors. And fortunately, the consequences of venturing out in the summer without bug spray are usually little more than itchy bumps.

But that’s not the case elsewhere around the world, where mosquitoes are responsible for hundreds of millions of cases of illness and millions of deaths each year. They’re easily the world’s deadliest animal, even more so than humans.

Malaria is a particularly devastating mosquito-borne illness. About half of the world’s population lives in areas at risk of malaria, which sickens millions and kills hundreds of thousands of people each year, most of them in Africa.

One group of species — Anopheles gambiae — out of the roughly 3,500 types of mosquitoes on earth is responsible for most of that epidemic. And researchers recently announced that they successfully tested a gene modification technique that could cause entire populations of Anopheles gambiae mosquitoes to selfdestruct.

There’s just one small catch. We don’t really have any idea what would happen without mosquitoes. They’re food for other animals, they help pollinate plants, they compete with other nasty animals.

Getting rid of them could be a disaster, or it might not make much of a difference at all.

According to a report published recently, scientists have figured out how to genetically engineer mosquitoes that pass along sterility when they mate. An entire population can be wiped out in a few generations, which for mosquitoes would take just a few months.

Humans have experimented with lower-tech methods of mosquito eradication for decades. In fact, the United States struggled with malaria until the 1950s, when aggressive pesticide spraying and other anti-mosquito efforts effectively eradicated the disease here.

Lots of counties still routinely spray for mosquitoes, although not without some controversy. And yet, the biting pests remain very much with us.

In remote places with minimal infrastructure and yearround mosquito breeding seasons, the challenge is even tougher. So scientists have been trying to come up with a more effective solution than pesticides.

What little research has been conducted on the importance of the Anopheles gambiae mosquito suggests that eradicating it might not have much of an impact. They certainly wouldn’t be missed by humans.

But far more study will be required before releasing genetically engineered, self-destructing insects into the wild.

Of course, research on genetically altered mosquitoes raises broader ethical and ecological questions as well. Harmful artificial genetic traits that can rapidly spread through a population could be used as a powerful biological weapon, for example.

Billions of species have come and gone in the long history of our planet. More than a few of them owe their demise to humans. Life on earth is still soldiering on, at least for now.

Any chance to wipe out malaria and other massively destructive diseases merits investigation. But if we’re going to intentionally eradicate a species, we’d better make sure we fully understand the consequences.