Boulder, Colo. — BIOTECHNOLOGISTS have engineered the mosquito that spreads the Zika virus to pass a lethal gene to its offspring. Another team of researchers has devised a way to spread sterility through the mosquito population, using a technique called gene drive to wipe out the offending insects.

If regulators approve this genetic tinkering, these insects could become a powerful weapon against the spread of mosquito-borne diseases to humans. But bugs like these, and the techniques used to create them, might have another role to play: helping to protect the earth’s biodiversity.

This kind of genetic meddling makes many environmentalists deeply uncomfortable. Manipulating nature’s DNA seems a hugely risky and ethically fraught way to help save the natural world. And yet, we may need to accept the risks.

On Hawaiian islands, for instance, avian malaria transmitted by mosquitoes is decimating native bird populations. Warmer temperatures have exacerbated the threat, allowing mosquitoes that carry the malaria parasite to invade higher-elevation areas that are the last holdouts for some birds. These losses ripple down through food chains, disrupting ecosystems.