Application of Bti to protect Kaua‘i's forest birds

Kaua‘i is home to unique and rare forest birds that are declining at alarming rates due to avian disease. ‘Akikiki are extinct in the wild and 'akekee and other honeycreeper species are reaching perilously low population numbers. To control avian malaria and protect forest birds, we will resume the aerial application of a highly mosquito-specific biolarvicide, Bti (Bacillus thuringiensis israelensis) over >1100 acres of forest bird habitat on Kaua‘i in 2026-2027. Applications will occur every two weeks to suppress mosquito populations. Monitoring of treatment efficacy will be conducted every five weeks in the treatment area and a reference area. Project objectives are 1) to apply Bti every two weeks to suppress mosquito populations in the treatment area, 2) monitor treatment efficacy by a) using larval assays to verify adequate rates of Bti deposition, and b) suppression of adult mosquitoes using mosquito traps, and 3) conduct public outreach to support the program.