Kauaʻi Mosquito Suppression Final EA-Complete

Hawaiʻi’s native forest bird species have undergone precipitous declines and extinctions since the arrival of humans to the archipelago, particularly Europeans; 39 of the 56 native Hawaiian honeycreepers have gone extinct and 11 of the remaining 17 species are endangered or threatened. Although several factors have led to declines of these remaining species, the main threat to Hawaiian honeycreepers is currently avian malaria (Plasmodium relictum) and avian pox (Avipoxvirus spp.); non-endemic diseases that are principally spread by the non-native invasive southern house mosquito (Culex quinquefasciatus). Until recently, there were no viable means available to control mosquito vectors at the landscape scale within natural areas in Hawaiʻi.

The Incompatible Insect Technique (IIT) is neither novel nor an experiment, but the application of an established method for controlling insect populations. Based on existing literature, IIT has been successfully implemented to control mosquitoes that are a human health concern in at least 17 countries worldwide including, but not limited to, New Caledonia, Fiji, Vanuatu, Australia, French Polynesia, Indonesia, Singapore, Malaysia, Vietnam, Thailand, Sri Lanka, India, China, Brazil, Columbia, Mexico and the United States (Florida, California, Puerto Rico, Texas, Kentucky and New York). The technique uses lab-raised male mosquitoes carrying a select strain of Wolbachia, a bacterium that naturally occurs in at least 65% of insect species. When male mosquitoes, which do not bite or transmit diseases, are released into a target habitat and mate with wild female mosquitoes that either contain different or no strains of Wolbachia, the eggs fail to develop owing to the cytoplasmic incompatibility of the differing Wolbachia strains of the male and female mosquitoes. The development of IIT for mosquito-borne diseases that affect humans presents a unique opportunity to use this tool to control mosquitoes that spread avian diseases to native forest bird species in Hawaiʻi. This approach does not employ genetic engineering and does not involve or result in the genetic modification of either mosquitoes or bacteria.

The State of Hawaiʻi Department of Land and Natural Resources (DLNR) and U.S. Fish and Wildlife Service (USFWS) proposes employing IIT to reduce mosquito populations within approximately 59,204 acres (23,959 hectares) of forest reserves, state parks, and private lands in the Kōkeʻe and Alakaʻi Wilderness areas of Kauaʻi to protect birds from mosquito-borne diseases in key higher-elevation native forest bird habitat. This effort is consistent with the statutory missions and responsibilities of the DLNR and USFWS. The multi-stakeholder project would raise and sequentially mass-release male mosquitoes that carry a strain of Wolbachia that is incompatible with natal females. Extensive pre- and post-release monitoring would be implemented to monitor the effectiveness of releasing incompatible male mosquitoes on the wild mosquito populations. A similar unconnected project has been proposed for implementation by the National Park Service and DLNR on the island of Maui1. To comply with their respective obligations under the National Environmental Policy Act (NEPA) and Hawaiʻi’s environmental review process pursuant to Hawaiʻi Revised Statutes (HRS) Chapter 343, the USFWS and DLNR are preparing a joint environmental assessment (EA) to address the impacts of the release of male mosquitoes with incompatible Wolbachia in the Kōkeʻe and Alakaʻi Wilderness areas.