Mosquito population control project earns a key approval
Conservation officials hope to deploy the tool to save native birds
A project that would slow the spread of avian malaria with “mosquito birth control” received another green light this week as conservation organizations try to save Maui’s critically endangered native forest birds from extinction.
The state Department of Agriculture’s Advisory Committee on Plants and Animals unanimously agreed on Thursday to recommend to the Board of Agriculture to list, allow importation and establish permit conditions for field release of three mosquito species — all of which are already present in Hawaii — as part of efforts to introduce incompatible male mosquitoes to wild populations that are threatening honeycreepers, which are found nowhere else in the world.
This decision will allow the Birds, Not Mosquitoes project and its partners of state, federal and nongovernmental organizations to proceed with applying for an import permit for the incompatible-male mosquitoes to be used over large landscapes in Maui and Kauai by 2024.
“This technique is the most promising tool we have,” said Luka Zavas of the American Bird Conservancy during a town hall hosted by Maui County Council Member Kelly Takaya King on Thursday night.
This tool has been used successfully worldwide for public health reasons to mitigate the spread of disease among people. However, if this project launches in East Maui’s forests, it would be the first time that the incompatible insect technique has been used for conservation work to save endangered species.
“Hawaii’s endangered forest birds are nearing extinction at an accelerating pace, but we actually have new technology that’s available that we can bring to bear to save our species from extinction and possibly bring them to abundance,”
said Jonathan Likeke Scheuer of Kahalawai Consulting LLC. “For us, it’s not just about saving the birds. It’s also about saving the bio-cultural relationships that we have with our birds and our birds have with our forests.”
A technique described as “mosquito birth control” would be used by federal and state conservation agencies, like the National Park Service, The Nature Conservancy and the state Department of Land and Natural Resources, as a way to reduce the reproduction of mosquitoes and prevent the extinction of Hawaii’s native forest birds as they fall victim to avian malaria.
In the event there is another human disease outbreak transmitted by mosquitoes in Hawaii, the state Department of Health also acquired permits to use the same technology — used in other countries — to protect human health, Scheuer said.
The birth control method uses male mosquitoes, which do not bite, with a strain of a bacterium called Wolbachia that is incompatible with the strain of Wolbachia currently found in wild mosquitoes in Hawaii, said Zavas, who also does outreach for the Birds, Not Mosquitoes project.
When the male mosquitoes mate with females in the forest, the eggs do not hatch and the mosquito population size drops, she added.
Despite rumors, Scheuer said that no genes are modified in the mosquito or in the Wolbachia bacteria.
The mosquito species permitted for importation include the southern house mosquito (Culex quinquefasciatus), which is responsible for sharp declines in the populations of many honeycreeper species on Maui, Kauai and Hawaii island, as well as the yellow fever mosquito (Aedes aegypti) and Asian tiger mosquito (Aedes albopictus), which transmit human diseases, according to the Department of Agriculture.
The timeline to implement the landscape-scale mosquito control in Hawaii continues with testing and developing mosquito populations on the Mainland, which includes separating males and females and then making sure the males are in fact incompatible; importing millions of the species to Hawaii; and then developing release technologies, such as by helicopter, by staff hiking in or by drone.
“We’re trying to do this as thoughtfully and with as much public involvement as possible, but at the same time, knowing that some of our birds are now facing mosquitoes year-round and some of our species possibly dying from one bite, doing this as fast as possible, so that we can get this technology our into our forests,” Scheuer said.
Once on Maui, the mosquitoes could be released anywhere from every two weeks to every two months, with the number of mosquitoes per release is still under review, said Hanna Mounce, coordinator of the Maui Forest Bird Recovery Project.
“It’s definitely going to be a very labor-intensive process,” Mounce said. “We have to target where the birds currently are in order to, you know, stop this imminent threat and then after that, if this is really successful and this is working really well, which we really hope that it is going to be, then we can look at something that’s even more hopeful, like expanding the habitat that they have.”
Haleakala National Park spokeswoman Jin Harlow said that next steps also include planning and writing an environmental assessment for Maui, which will be completed in August or September.
The public will have a 30day comment period on the draft EA upon completion before NPS and the DLNR make a final decision in November or December.
Meanwhile, an EA will be initiated for Kauai and a statewide EA will be developed thereafter.
In 2023, the Birds, Not Mosquitoes project will obtain an emergency use permit and/or emergency exemption permits and other registrations, as well as begin small-scale field tests, monitoring and researching, Scheuer said.
By 2024, the group hopes to launch landscape-scale releases on Maui and Kauai and follow with monitoring efforts. If all goes well, statewide releases will take place the following year.
Hawaii is set to receive $14 million under the Bipartisan Infrastructure Law to help support such efforts that would save at least four species of native Hawaiian honeycreepers from the brink of extinction on Maui and other islands.
There are only 17 species of honeycreepers remaining statewide, including six on Maui, Zavas said. Of the six found in the Valley Isle’s remote areas, three are endangered: ‘akohekohe, kiwikiu and i’iwi.
The mosquitoes that carry the disease have been invading the higher-elevation East Maui forests and slopes of Haleakala where the birds live, and warming temperatures paired with habitat loss are forcing birds higher up the mountains.
“We are really seeing the impacts of the disease and how climate change is pushing their demise along,” Zavas said.
Success of the “mosquito birth control” project can be measured through the native forest birds’ population sizes – whether the numbers are growing — and the prevalence of avian malaria found in mosquito specimens, Harlow said.
Research and monitoring will continue throughout the project, which the organizations involved say is low-risk, safe for human and other animal populations, and a situation in which unintended consequences have been “heavily vetted.”
“What is a very real possibility is the negative effects if we don’t do it,” Mounce said. “(Native forest birds) disappearing is a very real consequence of us not doing anything.”
For more information on the Birds, Not Mosquitoes partnership and mosquito birth control, visit the project website Birdsnotmosquitoes.org.