Genetically modified crops are not only devastating to your health, but they are also wreaking havoc on the environment. New research adds to the mountain of evidence that genetically modified crops not only require more pesticides — defeating one primary purpose of their existence — but lead to new insect populations that are resistant to the biopesticides contained in the crops. As insects adapt to the genetically modified Bt, the biopesticide becomes absolutely worthless, igniting a vicious cycle of further genetic alteration.
Bt is a toxin incorporated into genetically modified crops in order to kill different insects, however Bt usage has subsequently spawned insect populations which are resistant to the biopesticide. At least 8 populations of insects have developed resistance, with 2 populations resistant to Bt sprays and at least 6 species resistant to Bt crops as a whole.
What does this mean? Well, as a solution to the Bt resistance, biotech scientists are now creating even stronger genetically modified Bt as farmers use even more pesticides to combat the resistant bugs. However tests conclude that modified Bt toxin provided ‘little or no advantage’ in tackling the insects, despite extensive time and funding put into the research. It seems like an endless cycle in which scientists continue to genetically modify already genetically altered toxins in order to make them stronger and more effective against resistant insects — ultimately ending in insects that are immune to the most potent forms of Bt and other biopesticides. The ultimate effects that this volatile cycle will have on the environment is simply unknown.
Bt is a toxin from the soil bacterium Bacillus thuringiensis, which produces a large family of similar proteins that target different insect pests; and quite a few of them have been incorporated in genetically modified crops to act as ‘biopesticides’. Unfortunately, the pests soon develop resistance to it.
Bt resistance has not only been documented in the laboratory, but also in the wild, with at least 8 populations of insects have developed resistance, with 2 populations resistant to Bt sprays and at least 6 species resistant to Bt crops [1-10].
The emergence of resistance has pushed GM scientists to attempt new strategies of delaying its spread. New strategies include the genetic modification of the Bt toxin to kill pests that have already acquired resistance. Bruce Tabashnik and his colleagues at the University of Arizona, along with collaborators in Mexico, China and Germany, published a study in Nature Biotechnology this month showing that these modified toxins bypass their usual interaction with cadherin, a receptor in target insects that binds the Bt toxin in the first of a multi-step process causing bursting of cells in the insect gut . As some Bt resistant insects have been found to carry mutations in the cadherin receptor, they hypothesised that making Bt toxicity independent of cadherin binding would make pests susceptible to Bt once again. What they found however, was the opposite. Modified Bt toxin provided ‘little or no advantage’ against pests with cadherin mutations, while increasing Bt potency in pests where resistance was independent of cadherin mutations. The agrobiotech business Pioneer has significantly invested in these modified toxins despite the authors conclusions that ‘insects can probably adapt to modified Bt toxins used alone, or in combinations with other toxins’. This study exposes the lack of scientific understanding of Bt resistance as well as our inability to control it. As researchers search for ways of delaying resistance, resistance is evolving in the fields.
The first evidence of Bt-resistant western rootworm in the wild has been reported by a team of scientists in Iowa State University . Bt resistant pests have been emerging over the last few years, but as many scientists had warned, evidence now suggests that their resistance might not be recessive, i.e. need two copies of the Bt resistance gene to survive Bt crops. Instead, only one copy will do. This is hugely significant in terms of controlling the spread of Bt resistance through the pest populations. It also diminishes the efficacy of natural Bt toxin sprays used by organic farmers for pest control.
Following reports by farmers that their Bt maize fields (containing the Cry3Bb1 toxin) were showing signs of severe rootworm injury, Aaron Gassmann and his colleagues at Iowa State University decided to investigate the possibility of resistance to Bt toxin evolving in these pests. Their research is important, particularly in Iowa where the western rootworm is abundant. Further reports of Bt resistance in neighbouring Minnesota has also been documented .
With Bt crops, high selection pressures are being placed on target insects to adapt, especially considering their widespread cultivation. Resistance is not a controversial issue, but an acknowledged evolutionary process. Even Monsanto stated that  “resistance is natural and expected, so measures to delay resistance are important.”
This is not the first report of resistance to Bt toxins, although it took a few years for reports to emerge. It can be expected that resistance takes a few years to develop, and now we are beginning to see evidence of that. In 2009, cotton bollworm in four states of India devastated cotton crops, which was acknowledged by Monsanto . Field studies in Northern China and Australia have also documented resistance to Bt cotton crops in 2010 [14, 15].
Originally posted by Corruption Exposed
... genetically modified crops not only require more pesticides...
Originally posted by Corruption Exposed
For you to make your simple assumption that I was indicating Monsanto as the only culprit shows you're incapable of observing I was only providing an example.
Like seriously, there is no way you read the thread before you commented. I mentioned Monsanto once.