A million mosquitoes are falling from the skies over Hawaii every week.
To rescue some of Hawaii’s rarest birds from extinction, scientists are releasing one million mosquitoes into the wild—every week.
These are not ordinary mosquitoes. They are lab-bred males that don’t bite and are sterilized by a natural bacterium. When they mate with wild females, the eggs fail to hatch. Flood the forest with enough of these incompatible males, and the mosquito population crashes.
That collapse could save Hawaii’s honeycreepers—vibrant, jewel-like birds that once filled the islands with song. More than 50 species existed; only 17 survive, and most are on the brink.
The primary killer isn’t habitat loss. It’s avian malaria, carried by invasive mosquitoes that arrived in the 1800s. Native birds have no immunity. For decades, they survived only in cool, high-elevation refuges where mosquitoes couldn’t thrive. But warming temperatures are pushing the insects upward, and the birds have nowhere left to go.
Enter the Incompatible Insect Technique (IIT). The released males carry a strain of Wolbachia bacteria that renders cross-mating sterile. Packed into biodegradable pods, they’re deployed by drone and helicopter across steep, inaccessible terrain.
Currently, 500,000 mosquitoes are released weekly on Maui and another 500,000 on Kauai.
This is the largest use of IIT ever attempted to protect wildlife, not people.
If it works, it could give critically endangered birds like the ʻakekeʻe and kiwikiu a fighting chance to rebound—and perhaps even develop resistance. But conservationists warn: the window is closing fast.
["Thousands of mosquitoes are being dropped by drone over islands in Hawaii. Here’s why." Science, 5 November 2025]