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Additional Mosquito
Control Efforts
'I'iwi
PC: Graham Talaber
Mosquito Control Methods
When mosquitoes arrived in Hawaiʻi, native birds rapidly disappeared from the warm lowlands, succumbing quickly to avian malaria and pox. To help native birds survive, conservation organizations focused on habitat preservation and restoration in high-elevation forest preserves, which were too cold for mosquitoes. But as temperatures have warmed, mosquitoes have begun moving upslope, requiring mosquito control methods such as reducing breeding areas and spot-applying larvicides. Unfortunately, these measures alone cannot address the mosquito issue at a landscape scale across thousands of acres. An integrated management approach is necessary, including forest management tools such as fencing, invasive species removal, and native plant restoration, as well as more effective mosquito suppression tools including aerial deployment of Bti, a naturally occurring bacterial larvicide. By utilizing multiple techniques, and keeping current with the latest tools and developments in science, we are giving these endangered birds a renewed opportunity to thrive and flourish in the years to come.
I Ola Nā Manu Nahele.
Mosquito Control Methods Currently Being Used:
Biological insecticides, such as BT or "dunk" are commercially available for small or point-source control of mosquito larvae. However, effective landscape-scale application is difficult due to highly variable environmental conditions and dense forest habitats.
Learn more about current efforts to increase the effectiveness of these tools by reviewing these resources [link].
Captive breeding and the translocation of imperiled birds to safer places is a critical part of BNM's conservation efforts. BNM partners work with the San Diego Zoo on these conservation breeding efforts. You can learn more about them here.
'Akikiki are functionally extinct in the wild as of 2026. PC: Graham Talaber
Mosquito habitat reduction refers to the process of eliminating or modifying areas that serve as breeding grounds for mosquitoes. This approach involves identifying and targeting places where mosquitoes lay their eggs, such as stagnant water sources, and taking measures to eliminate or alter these breeding sites. Conservation groups have worked to erect fences to reduce the presence of pig wallows and have backfilled existing wallows and ruts in roadways to reduce mosquito habitat.
Landscape-scale mosquito habitat reduction is impractical in Hawaiʻi’s multi-layered forests, which contain micro-pools for breeding mosquitoes.
Mosquito Control Tools NOT Being Used:
1. Lethal Traps:
Deploying lethal “ovitraps” containing an insecticide is impractical across a vast, inaccessible landscape. If left in place for more than a few weeks, these traps can become breeding grounds and cause an increase in mosquito populations.
2. Spraying Chemical Insecticides:
In Hawaii's forests, conservation organizations sometimes carefully spot-apply herbicides to control invasive weeds. However, the broadscale application of chemicals to control mosquitoes, such as DDT, is complex due to dense forest cover and dangerous as it could harm plants and animals.
3. Genetic Modification:
While this project does not use genetic modification, researchers worldwide, including scientists at the University of Hawai‘i, are studying the potential of genetic techniques to protect human health and native species from the impacts of mosquitoes.
Like with Wolbachia IIT, genetic control strategies must carefully consider ways to ensure project safety and must be registered with federal and state agencies before use. Any future projects in Hawai‘i that utilize genetic technology would require public engagement, input, and regulatory approval.
4. IIT (The Incompatible Insect Technique):
We have paused the use of IIT as of 2026 to assess its efficacy. You can learn more about the project status here.
Native moths are just one of the many invertebrate species that could be harmed by chemical insecticide use. PC: Graham Talaber