SCIENTISTS CREATE GM KILLER
Two items on the GM Moths to be trialled in the US this summer. When biological control is so little explored and supported, what sense is there in launching GE biological control?
Don't know much about ecology
Don't know much biology
see also: http://www.ananova.com/news/story/sm_232932.html
US set to unleash genetically engineered insect
Scientists Create GM Killer - Moth To Control Pests - Trials Begin
By James Meek - Science Correspondent
The Guardian http://www.guardian.co.uk
Scientists are preparing to start trials of the world's first genetically modified insect, an unnatural born killer moth that will fly over cotton fields, passing a deadly gene on to its pestilent kin as an alternative to pesticide.
Although the GM moth will be released in Arizona, the technology used
to create the killer gene has been developed by a British team led by Luke
Alphey, of Oxford University. The scientists
believe that the chances of the killer gene spreading beyond the species it is intended to harm, the pink bollworm, is very small, and would do no harm if it did.
But the US department of agriculture still has to give consent for the first part of the trial, which would involve a tightly controlled release of moths with another gene inserted to track any possible cross-species transfer.
Scientists need to target the bollworm larvae, which feed on cotton plants, before developing into moths. The idea is to take insect eggs in the lab and insert into their DNA a gene from a fruit fly which would normally damage their metabolism so badly that they would die.
In the lab, however, the larvae survive, because they are dosed with
an antidote to the effects of the killer gene. They will grow into adult
moths, which are naturally immune to the effects
of the gene, and will then be released over the cotton fields in huge numbers.
Unaware that by mating they are both creating and assassinating the next generation, the GM moths will mate with wild moths and each other. The female moths will lay their eggs as normal. But their offspring will have inherited the killer gene. In the wild, the larvae will find no antidote and will die.
In the initial trial, which could take place next year, 3,600 moths
will be given a jellyfish gene that glows under special light instead of
the killer gene. This will show what happens to GM insects when they encounter
their wild counterparts and other species.
* * *
First biotech insect to be released in U.S. - March 8, 2001
WASHINGTON (AP) -- By tinkering with genes, scientists have made tomatoes hat stay fresher longer, crops that are immune to weedkillers and fish that grow faster. Now, a genetically engineered insect is emerging from the lab.
The first field trial of a biotech insect -- a pink bollworm moth that contains a jellyfish gene -- is planned for this summer. The gene gives the moth larvae a fluorescence that allows scientists to more easily track them and monitor their behavior.
If the experiment involving a major pest to cotton growers goes as planned,
scientists are ready with their next step: testing a biotech version, called
the "Terminator" by farmers, that is sterile, but sexually active; it is
designed to mate with wild relatives and eliminate their offspring.
Some 3,600 moths with the jellyfish genes are to be set free under screened cages in a government-owned cotton field near Phoenix. The next step would be to add genes that make the moths sterile.
"We're being very, very careful about what we're doing," said Robert Staten, an Agriculture Department scientist who will run the field trial.
The experiment is being conducted and regulated by department's Animal and Plant Health Inspection Service because of its authority for controlling plant pests. Staten expects the agency to grant approval this spring for the release.
"We're going to take as conservative an approach as we can and still
move forward," he said.
Some biotech critics are alarmed while some scientists who support the technology say the government is not prepared to properly regulate biotech insects.
Under development, for example, are disease-preventing mosquitoes that could deliver vaccines to the people they bite or carry their own antibiotics.
"When you're talking about insects you're talking about extremely promiscuous organisms that will mutate and breed quite uncontrollably," said Charles Margulis, an anti-biotech activist with the environmental group Greenpeace.
He said there is no guarantee that an insect designed to be sterile will turn out that way. The pink bollworm moth infects about 500,000 acres (200,000 hectares) of cotton in the Southwest. Farmers currently have three options to control them: spraying a lot of insecticide; planting an expensive variety of genetically engineered cotton that makes its own insecticide; or by releasing moths sterilized by irradiation.
Irradiated moths are less effective in areas with heavy infestation because the treatment damages the insects so much that they are slow to mate. The genetically engineered moth is designed to have the same sexual prowess as its wild cousins.
"He'd be fully sexually aggressive and go out and meet and breed. He'd be the first guy in the bars at night," said John Benson, a farmer in California's Imperial Valley and a member of the California Cotton Pest Control Board, which has funded the research through producer fees.
"We see this as the one sure way to get eradication," he said. It takes 60 irradiated moths for every wild one to make sure there are enough to mate and eliminate the chance of offspring. With the biotech moths, a 5-1 ratio is sufficient, said Thomas Miller, a University of California-Riverside entomologist who developed the moth.
The biotech moths would be cheaper for farmers to use than the gene-altered cotton, Miller said. The biotech cotton, although highly effective, costs farmers up to $30 an acre (0.4 hectare) more than conventional cotton.
Some biotech critics are concerned that overuse of the gene-altered cotton, known as Bt for the insecticide it contains, will lead to an increase in insect resistance to Bt sprays, which are used on fruit and vegetable crops.
Use of a biotech moth to control pink bollworm infestations makes that resistance less likely to develop, said Charles Benbrook, an agricultural consultant to environmental groups.
This summer's experiment with the biotech moths will be conducted in three cages, each about 12-feet wide by 24-feet long. The cotton field in which they are placed is surrounded by a 6-foot chain link fence to deter vandals.
There is little chance of the moths escaping "barring a major weather catastrophe," according to the application for the release.
As a precaution, the moths containing the jellyfish genes will be irradiated
to ensure that even if they do escape they can't reproduce. The gene-altered
moths will then be studied to see if there is any unusual behavior.