RELEASING MOSQUITOES TO HELP KAUA‘I’S FOREST BIRDS

News Release from DLNR, Feb. 14, 2025

ALAKAʻI PLATEAU, Kauaʻi – It seems counterintuitive to release hundreds of thousands of mosquitoes into an area where the insects are spreading avian malaria and bringing several species of Hawaiian honeycreepers to the precipice of extinction.

Nonetheless, staff from the Kaua‘i Forest Bird Recovery Project (KFBRP) heralded Thursday’s first release of male mosquitoes, into a state forest reserve on the vast Alakaʻi Plateau, as momentous.

Ten years of planning, permitting and community outreach led the team and its partners, to the release of male mosquitoes that are reproductively incompatible with female mosquitoes, which bite and spread the often-deadly disease.

“Incompatible Insect Technology, or IIT, leads to mosquito population suppression, and we hope it will reduce the amount of avian malaria which is driving the declines of native forest birds,” explained Dr. Lisa ‘Cali’ Crampton, the head of KFBRP.

IIT has been deployed successfully around the world, mostly to combat human malaria. This is the first time it’s been used on Kaua‘i as a biological control to try and severely reduce the number of malaria-carrying mosquitoes. “It is a tried and true and safe technique that has been used hundreds of times,” Crampton said.

The mosquitoes are flown from a facility in California and each week, half a million bugs will be loaded onto a helicopter in biodegradable cones that resemble an ice cream sugar cone.

The deployment helicopters are outfitted with a specially designed tube which directs each cone out of the bottom of the aircraft, where they float to the ground. “We do this twice a week to ensure there’s a very, very high likelihood that a wild female will encounter one of the incompatible males. We’re really trying to interrupt the reproductive cycle,” explained Crampton.

She says she is very hopeful, a sentiment shared by DLNR Division of Forestry and Wildlife planner Justin Hite. He spent a decade leading KFBRP field teams into the remote areas favored by species like the ‘akikiki and the ‘akeke’e, two of the honeycreepers with such low numbers they’re likely to completely disappear from the wilds in the next year or two.

Hite observed yesterday’s releases and said, “We hope this really moves the needle for these species.”

The bird recovery teams are employing what Crampton calls, “integrated pest management.” In addition to the IIT releases, they’re using a common larvicide known as BTi, which targets one phase of the mosquito life cycle – the larval phase. It’s been  used on the ground on the Alakaʻi for nine years, and over the past year it’s also been applied from helicopters. IIT targets the adult stage and the egg production stage. “So, the idea is the BTi reduces populations of adult mosquitoes to begin with, making it more likely that females will encounter one of these incompatible males,” according to Crampton.

The insurance they have for the continued existence of the most critically endangered birds, are conservation breeding populations. Crampton said that once IIT and BTi have been used for a year or so over the best forest bird habitat on Kaua‘i, they remain hopeful birds in the conservation programs, or their offspring will one day be released back into the wild.

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RESOURCES

(All images/video Courtesy: DLNR)

HD video – Releasing Mosquitoes to Help Kaua‘i’s Forest Birds (web feature)

HD video – First IIT releases on Kaua‘i media clips (Feb. 13, 2025)

(Transcription/shot sheet attached)

Photographs - First IIT releases on Kaua‘i (Feb. 13, 2025)

KN: Momentous milestone reached in fight against often-deadly avian malaria on Kauaʻi : Kauai Now