Is mosquito eradication the answer? Scientists converge on BI to discuss curbing population

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KAILUA-KONA — A state absent mosquitoes would be a state absent Zika, dengue fever and chickungunya — not to mention those pesky mosquito bites.

KAILUA-KONA — A state absent mosquitoes would be a state absent Zika, dengue fever and chickungunya — not to mention those pesky mosquito bites.

And while residents can currently only fantasize about living in a mosquito-free Hawaii, a handful of experts are gathering on the Big Island this week to imagine ways of turning that fantasy into a reality.

Roughly 40 scientists, researchers and business people will convene at Kilauea Military Camp at Volcanoes National Park on Tuesday and Wednesday to discuss the feasibility of the implementation of one or several groundbreaking technologies to curb the mosquito population across the state — if not eradicate it entirely.

“We are discussing sort of how we realize the potential for a mosquito-free environment here for public health, conservation and quality of life issues,” said Durrell Kapan, co-organizer of the workshop and adjunct professor at the Center for Conservation and Research Training at UH-Manoa.

“There are a number of near-term and potentially longer-term solutions. The important thing is to make sure all the people involved are thinking about these solutions, and to get all those people in the room to understand what those possibilities are.”

Human health isn’t the only motivation. Conservation is also a top concern, which might sound ironic considering the notion behind the workshop is the limited geographic extinction of an insect.

However, the Culex species mosquito in Hawaii is capable of transmitting avian malaria and poses a threat to the native, endangered Hawaiian honeycreeper, as well as other bird species. It, along with the Aedes species mosquito that transmits Zika and was responsible for Hawaii Island’s recent dengue outbreak, are the targets.

How it can be done

Mosquito eradication proposals on the table for discussion sound futuristic to the layperson.

Dr. Kenneth Kaneshiro, program director at UH-Manoa’s Center for Conservation and Research Training, described three general options to attack the problem using an environmentally scaled, systems approach that would be applicable to other regions across the globe.

The first is a sterilization technique that would release sterile males into the wild to curb reproduction rates.

The second involves the harnessing of Wolbachia bacteria, which would inhibit viruses from entering the salivary glands of mosquitoes, rendering them impotent from a virulent standpoint.

The third is the implementation of gene drive technology, which is not yet ready for introduction into the natural environment, to ensure all offspring sired by genetically engineered mosquitoes would be born male. Kaneshiro said beta programs in South America utilizing the gene drive technique have shown 95-99 percent efficacy rates after only a few generations of breeding.

Consequences

The idea that intentional, human-engineered extinction should be employed as a means of conservation, or for any purpose, is not without its detractors.

“One danger is we, as human beings, are putting ourselves in a position to decide which creatures live and which we sacrifice,” said Claire Cummings, a journalist, author and environmental lawyer who will moderate a knowledge cafe on the topic of gene drive technology at this week’s International Union for the Conservation of Nature World Conservation Conference on Oahu. “Who put us in that position of natural authority? That is a major step for humanity to take, deciding what lives and what dies.”

The most critical question posed by those who share Cummings’ sentiment is an obvious one: What effect does the eradication of a massive insect population have on Hawaii’s ecosystem?

A common misconception is that the extinction of predators atop the food chain has the most profound effect on ecological systems.

In actuality, removing a seemingly ineffectual nuisance like the mosquito could potentially produce far greater consequences than the extinction of a large mammal.

Several species prey on mosquitoes — like the endangered hoary bat, for example. If mosquitoes cease to exist in an ecosystem, that causes a food shortage for species like the hoary bat, the populations of which are threatened in turn. Many of those threatened species also provide food sources for other species.

The potential effect up the ladder could be equated to a tumbling row of dominoes.

But Kaneshiro, who has encountered this question several times over the last year, pointed out a factor he says is crucial to remember: Mosquitoes are a non-native species, one that didn’t arrive in Hawaii until the early 19th century, and the ecosystem worked just fine before they got here.

“Eradication of mosquitoes wouldn’t cause any other problems because they’re not native to Hawaii,” he said.

“They’re an invasive species that doesn’t belong in the native Hawaiian ecosystem.”

Kapan said some fears should be assuaged, as conversation at this week’s workshop will include consideration of not only environmental issues, but ethical and social concerns as well.

The catalyst

Kaneshiro, who is not a mosquito expert, coordinated the workshop after he was contacted a year ago by a representative of the IUCN inquiring as to whether or not responsible eradication of mosquitoes in Hawaii was possible. Following the Zika explosion, a representative of Sen. Brian Schatz’s office called with the same question.

In concert with several colleagues more in tune with the topic, Kaneshiro determined Hawaii was a more than suitable venue to host a proof of concept experiment to determine the best strategic solution for addressing mosquito-borne diseases.