“Our approach to nature is to beat it into submission. We would stand a better chance of survival if we accommodate ourselves to this planet and viewed it appreciatively instead of skeptically and dictatorially.” ~ E. B. White
Genetically Modified GM Mosquitoes have been released into the “wild” in the Cayman islands as a biological control for Dengue mosquito; the general public were informed almost a year after the first release; the experiment was considered “successful” less than a year after the 2nd most significant release; 5 similar trials to occur over the following year in other places in the world.
The company who owns the GM mosquito is called OXITEC; they have developed 2 types of GM dengue mosquitoes; both are effective after the egg hatches; in one type (used in the Cayman Islands Experiment) the offspring all die at the larval or pupal stage and in the other female offspring cannot fly or feed and therefore cannot mate……. both of these traits can be overcome if the mosquitoes are given tetracycline in their food source.
This repression of the trait is built in so the company can reproduce the mosquitoes for retail on a large scale.
It seems large quantities of the GM mosquitoes must be released and over and over; for this small project covering just 40 acres/16 hectares it is said over 3 million eggs were sent from England to the Caymans and they are monitoring the land to see what other releases will be needed to keep the populations down. This often effects sustainability of projects like this as smaller countries cannot afford to keep buying the product that keeps the mosquitoes down.
This is an insect control technique called RIDL: Release of Insects carrying a Dominant Lethal. It is a Sterile Insect Technique (SIT) but the SIT programs of the past have mostly irradiated insects to make them infertile. Shockingly the irradiated mosquitoes were too weak to carry out their job and mate with the females and their lifespan was shortened so scientists looked for another way.
These new introductions to the environment have had a genetic element integrated, into their DNA. The adult mosquito remains healthy and sexually viable. However, the added genetic element is passed to the offspring where it is fatal, thus providing a genetic alternative to radiation-sterilization.
The added genetic element, however, can be neutralized by the administration of tetracycline. This control mechanism is claimed to both allow the GM strain to be reared in sufficient numbers in captivity, and also insure that the same strain cannot replicate in the wild – since without the administration of tetracycline, offspring will die.
Not being an expert but I have to wonder about this cause tetracycline is a common antibiotic and studies have shown for over 10 years that it has contaminated water sources all over the world. Studies are also showing links between antibiotic contaminated water sources and antibiotic resistance in nearby animal populations. Now how are we going to guarantee that these insects do not come in contact with tetracycline contaminated water? Was tetracycline tested for in the Cayman Islands water systems?
“It’s a self-limiting system, you release sterile males, they mate with wild females and the progeny die before they can bite and transmit disease. If you release them for long enough the wild population will decline and collapse,” says Luke Alphey, research director of Oxitec.
Mosquitoes are troublesome and need to be controlled but they have been on earth for 210 million years and they exist in virtually every type of habitat in every country. There are 1,000’s of varieties and they do serve some roles in the eco system.
I would always be concerned if the goal of any program is eradication or collapse of a species.
Not being an expert but I would think a proper environmental assessment could not be completed until we checked back in 5 year increments for 20 years and asked the following questions:
There was an 80% immediate reduction rate in one year but what about over longer intervals such as 1, 5, 10, 15 or 20 years? They were not sure in press releases how long it would be before needing to be resprayed; this can greatly effect the sustainability of the project.
How do fish, birds, bats, frogs and other species fare who eat mosquitoes containing an enzyme that multiplies in the body until larvae die unless administered tetracycline?
How do humans who eat fish/birds/reptiles who have eaten these mosquitoes fare?
Have new species stepped into the void created by the eradication of this mosquito?
Have populations of mosquito in the vicinity been effected either showing increases or decreases? Mosquito populations are stabilized by density-dependent effects – in some cases of SIT insufficient release ratios have increased mosquito populations.
What could happen when females with the altered DNA are released and they mate with the wild population or bite and inject saliva into humans or other hosts? According to a research paper from Oxford University published in 2007 there is a rate of < 1% female after filtering processes with as low as 0.1% female if larger males are also discarded.
It has recently been proven in Indonesia that the male can be a vector for dengue in 30% of cases and this is a new tendency in these mosquitoes. Has this been considered?
Has it been shown that a very small percentage of pupae and larva from these GM modified mosquito males do survive even though tetracycline has not been administered? Is the efficiency rates 100%?
Has plant life within the study area and the regions nearby been monitored? Mosquitoes are generally nectar feeders therefore potential pollinators. Only the females drink blood and then usually only to develop eggs.
What do the fish, birds, bats, frogs and other species who eat this species of mosquito do when they are gone? Have measures been set in place to quantify any changes in population or diversity of the creatures that use these mosquitoes as a food source?
Have measures been put into place to verify and ensure that the enzyme cannot escape the DNA of the mosquito and enter the environment as the chemicals inserted into the genes of genetically modified plant genes have escaped to enter the soil and water nearby (even though we were assured this could not happen).
How can we be sure that this same enzyme cannot enter other species as genetically modified crops have produced super weeds?
How can we be sure that future scientific discoveries are not being prevented?
Mosquitos and other blood sucking insects produce a “sophisticated salivary cocktail of potent pharmacologic compounds. Recent advances in transcriptome and proteome research allow an unprecedented insight into the complexity of these compounds, indicating that their molecular diversity as well as the diversity of their targets is still larger than previously thought.” – Medical Entomology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Maryland.
Check out the press release on Youtube released by Mosquito Research and Control Unit in the Cayman Islands.
This even opens questions in my mind.
They say it has been researched for years and years but I would like to know the length of time this particular genetic modification has been studied.
They say that these males are sterile but they are not; they produce young that die before they become harmful; that is different.