Thursday, November 26, 2015

Can we GMO our way out of the mosquito mess?

There has been a great deal of controversy about terminator gene technology in plants, but similar genetic processing in insects, not so much.

Perhaps it's just because we don't like a lot of insects, but also because insects are particularly effective ecosystem invaders, plant pests and disease vectors.

Think Vespula vulgaris, the meat-eating alien wasp that is wiping out native pollinators on Haleakala. Think centipedes, also not native. Think the more than 40 species of ants, all of them imports. There are several introduced species of fruit fly now, which fill fruits with squirming maggots. Think ground termites, B52 cockroaches and, of course, mosquitoes.

No mosquitoes existed in the Islands until they arrived via a contaminated water cask on a whaler in the 1800s. Now there are multiple species. They suck your blood, and depending on species, they spread diseases that are killing off native forest birds. And then, of course, there is our latest scourge, dengue fever.

In a sense, technology caused this problem. Mainly transportation technology, which gets things--all kinds of things--to the Islands quickly.

Can technology fix it? Maybe, and there are lots of people working on it.

"Terminator" technology in plants has been developed but never used in production agriculture. It renders seeds sterile at harvest. That means you can't replant your seeds, but also means the genes can't spread.

Some folks consider it a spooky technology for crop plants, but what about pest insect control?

A British firm, Oxitec, has developed a bioengineered Mediterranean fruit fly that will mate with wild flies and pass on a trait that prevents female offspring from maturing, and thus prevents them from reproducing. Very specific, so unlike insecticides, no other species--like pollinators
and attractive butterflies, are impacted. It's about to be tested indoors in Australia.

Oxitec has also developed a response to the mosquitoes that carry dengue fever. It is a slightly
different technology, creating sterile males, which mate with females, but no viable eggs are produced.

Other researchers are working on technology that causes mosquitoes to only produce male offspring.

U.S. scientists in California have produced a version of a malaria mosquito that can't become infected with malaria--you've still got the mosquito, but it can't make you sick.

Genetic engineering is hardly the only tool being developed to control insect pests. Alternatives include sterilizing radiation and chemical technologies.

There are questions of efficiency and morality in all this.

If you take the approach of stopping a bug from passing on a specific disease, then you need a technology for dengue, and one for avian pox, and one for human malaria, and one for avian malaria, and one for chikungunya. There are issues. Pox and dengue are viruses. Malaria involves a parasite.

The solutions need to be different.

And there is the public outcry about genetic modification of anything. Tens of thousands of people have signed petitions to stop the release of genetically modified mosquitoes that would help stop disease.

And you would still have the mosquitoes.

The technology can also be used to greatly reduce numbers or even eradicate a species,of mosquito. In some parts of the world that is opposed on moral or environmental grounds since mosquitoes are a part of the natural ecosystem.

In Hawai'i, they are alien invaders, deeply disruptive to our natural environment, both annoying and sometimes dangerous around our communities, and entirely unwanted except by a few creatures that feed on them. Different story,, although the issue of releasing genetically modified organisms is still there.

The technology to address the issue will come in several forms, and each alternative will have impacts. Doing nothing may have even greater impacts.

{c} Jan TenBruggencate 2015

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