Blow to GM lobby as bugs build resistance against Frankencrops
‘Techno-farming does not work’
insects are rapidly developing resistance to crops that have been genetically modified to stop common pests.
A major study of so-called Frankencrops designed to produce a bug-killing protein called Bt found a five-fold increase in resistance.
this ‘ substantially’ reduced the effectiveness of the GM crops in 16 cases, compared to just three in 2005.
Researchers found that it took just five years for the bugs to be able to shrug off the poison. Bt is also used as a spray-on insecticide but scientists say it is less likely to spread resistance in its spray form as it rapidly breaks down in the environment.
Bruce tabashnik and Yves carriere from the college of Agriculture and Life sci-
ences at the University of Arizona analysed global data on Bt crops and how insects adapt. Professor tabashnik said: ‘When Bt crops were first introduced in 1996, no one knew how quickly the pests would adapt.
‘now we have over two billion acres of these crops planted during the past two decades and extensive monitoring data, so we can build a scientific under- standing of how fast the pests evolve resistance and why.’ While 16 out of the 36 cases they studied showed resistance, 17 did not. A further three showed ‘early warnings of resistance’.
it is still illegal to grow GM crops in the UK – with exceptions granted for scientific research – butthe way world.theyof slowingare the widelythe researchers developmentgrown aroundsaid of a resistance was by planting ‘refuges’ of non- GM crops close to modified varieties. this increases the chance that a bug with genes that can shrug off Bt will mate with one that does not – making it less likely the resistant genes will be passed on. Professor tabashnik, whose work is published in the journal nature Biotechnology, said: ‘i see these crops as an increasingly important part of agriculture. We expect the pests to adapt. However, if we can delay resistance from a few years to a few decades, that’s a big win.’
Anti-GM crop campaigners said the findings show that GM crops are acting as predicted – and spreading resistance to insects.
Liz O’neill of GM Freeze said: ‘this study confirms a very simple truth: if you try to outwit nature, it’s evolution that wins.
‘We already know that if you grow herbicide-tolerant GM crops you get herbicide-resistant weeds. now we have clear confirmation that the pattern repeats itself with insecticide-producing crops.’
Pat thomas of Beyond GM said: ‘this report shows that technofarming does not work. But the other issue is that these Bt plants are actually registered as pesticides – and yet regulators still say they are safe for us to eat.’