A British biotechnology company called Oxitec has genetically engineered a new breed of olive tree fly that could stop their natural counterparts from ravaging olive trees in Spain. 
 
 The altered flies are implanted with a gene that causes female offspring to die in the larval stage. Males will grow old with the gene, and soon won't have anyone to mate with. In a controlled experiment conducted by the UK scientists, according to New Scientist, the population crashed in about 10 weeks. 
 
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 Olive tree fly larvae eat through 15% to 30% of the crop each year, making them much more than a nuisance to anyone whose income depends on the fruit. 
 
 For now, Oxitec is waiting for the go-ahead from the National Biosafety Commission in Spain. But in Brazil, a similar experiment is well under way in the wild. The scientists have engineered dengue-carrying mosquitoes around the city of Mandacaru to produce offspring that will all die before they can reproduce. 
 
 The company claims to have killed off 96% of the dengue mosquito, but there are those who believe their method of doing so is dangerous. 
 
 GeneWatch UK, a nonprofit dedicated to investigating how genetic science and technology affects everything from food to society in general, is concerned that this method of species control doesn't have enough oversight. They believe that the relationships this species of mosquito has with other mosquitoes have been oversimplified, meaning the insects could intermingle and cause other populations to deteriorate. 
 
 But Oxitec CEO Hadyn Parry says that its method is much more practical and safe than, say, using insecticide. 
 
 "Insecticides will kill many species — whether the target or a beneficial insect so they can have quite a broad impact in the environment," Parry wrote in an e-mail to Mashable. 
 
 He also suggested that his method is better for people, too. 
 
 "The mosquito lives and breeds very close to humans — so they live in and around the home," Parry said. "So with pesticides you need frequent and total access to people’s homes to spray or fog." Many people don't want those chemicals near where they live, of course. 
 
 Oxitec's main focus for now is on the mosquitoes, but they have developed a few more bugs for different purposes, including one that can control populations of cotton-eaters. 
 
 Does controlling populations through genetic tweaking sound safe to you? Let us know in the comments. 
 
 Image: Flickr, Reini68 ||||| GM insects are go. Genetically modified versions of a fly that decimates olive trees could soon be released in Spain in an attempt to control the pests. And in Brazil, GM mosquitoes are already at large as part of the biggest project yet involving engineered insects. The aim is to stamp out their natural counterparts, which carry dengue fever. 
 
 The techniques are opposed by anti-GM groups, but advocates say they offer a real alternative to spraying insecticides, and have the potential to provide a better and more precise tool to combat agricultural pests and insects that spread human diseases. 
 
 The olive fruit fly is a major pest to olive growers in the Mediterranean and California. Females lay their eggs in the fruit and the larvae destroy 15 to 30 per cent of the crop each year as they munch their way to freedom. To tackle this, Oxitec, a biotech company based in Oxford, UK, has submitted an application to the National Biosafety Commission in Spain to release a small contingent of male GM olive flies, in what would be the first field trial of its kind in Europe. 
 
 The males are equipped with genes that cause any female offspring they sire to die while they are still in the larval stage, before they have had a chance to reproduce. The idea is that the male offspring inherit the lethal genes and continue to propagate them through the population, until the number of females dwindles to zero and the species crashes. 
 
 In lab experiments, the designer flies successfully competed with non-GM males for mates and caused the population to nosedive within 10 weeks (BMC Biology, doi.org/nvd). To check this happens in the wild, the trial would involve releasing the engineered flies under six olive trees in the Tarragona province, draped in mesh netting to prevent escape. 
 
 As the Spanish authorities mull the application, Oxitec is continuing with an even bigger trial to combat dengue fever in Jacobina, a city of 50,000 people in the Brazilian state of Bahia. The aim: to run local mosquitoes that transmit dengue out of town. 
 
 The principle is almost the same as with the olive flies – send out an army of male mosquitoes equipped with genes that prevent any offspring, male or female, from reaching breeding age. "Our males are mating at the frequency we'd hoped," says Luke Alphey, co-founder of Oxitec. 
 
 In a preparatory field study elsewhere, the team showed its mosquitoes reduced the native population by between 80 and 96 per cent within six months. "The new programme is less about 'does this work?', and more about the first operational roll-out of this technology," says Alphey. 
 
 The main benefit of the GM insect method, says Tony Nolan from Imperial College, London, is that it is "strictly species-specific" as the insects only seek out mates of the same species. Controlling the pests with insecticides wouldn't be so discriminating. 
 
 However, opponents, such as GeneWatch UK, say there are unanswered questions about the insects, whether they will spread unpredictably, for example. They also point out that sites cleared of insects would eventually be reinvaded. Alphey counters that similar work using males sterilised with radiation has shown that reinvasions can be controlled for decades by simply releasing more insects. 
 
 This article appeared in print under the headline "Designer insects join fight against pests and disease" 
 
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 If you would like to reuse any content from New Scientist, either in print or online, please contact the syndication department first for permission. New Scientist does not own rights to photos, but there are a variety of licensing options available for use of articles and graphics we own the copyright to. ||||| This photo provided by the Centers for Disease Control and Prevention (CDC ) shows a feeding female Anopheles stephensi mosquito. (James Gathany/CDC via AP) 
 
 In the history of the world, few weapons have been more destructive than a tiny mosquito bearing a microscopic dose of malaria. 
 
 The disease is one of Earth’s oldest and deadliest. It may have infected the dinosaurs. It’s been found in the mummified remains of ancient Egyptians. It’s thought to have killed Genghis Khan. One Nobel Prize-winning scientist even went so far as to suggest that malaria may be responsible for half of all human deaths, ever. 
 
 And despite our fiercest efforts at treatment and eradication — bed nets, quinine pills, pesticides, vaccines — the illness persists in killing us, to the tune of roughly half a million deaths per year. 
 
 So scientists are trying a different tactic: Instead of treating the humans, why not treat the mosquitoes? 
 
 On Monday, researchers from the University of California’s Irvine and San Diego campuses reported in the Proceedings of the National Academy of Sciences that they’ve bred a strain of mutant bugs that could all but eliminate malaria from the world’s mosquito population. 
 
 The breakthrough relies on a controversial new gene-editing technique called CRISPR-Cas9, a sort of molecular cut-and-paste that allows scientists to snip out segments of a creature’s DNA and insert new ones. With CRISPR, the California researchers added a set of genes conferring malaria resistance to their mutant mosquitoes, as well as a powerful tool called a “gene drive” that guarantees that all of the mosquitoes’ descendants would inherit their resistance. 
 
 [Why we should all hope to get bitten by a GMO mosquito] 
 
 “Gene drives” work by manipulating the laws of genetics so that the desired genes are copied onto both of an offspring’s chromosomes when a mutant mates with a wild mosquito. Ordinarily, offspring get just half their traits from each parent — but with the mutant inserting its DNA into both chromosomes, mosquitoes with the gene drive were able to pass on the resistance to 99.5 percent of their offspring, the researchers say. 
 
 According to the New York Times, the gene drive has the potential to spread malaria resistance throughout a wild population in a matter of just 10 mosquito generations, or a single summer. 
 
 Kevin Esvelt, an evolutionary engineer at Harvard University who studies the technique in yeast and wasn’t involved in the mosquito study, called the research a “major advance.” 
 
 “This work suggests that we’re a hop, skip and jump away from actual gene drive candidates for eventual release,” he told the Associated Press, 
 
 For now, the mutant mosquitoes are being kept in a highly secure lab behind a series of locked doors. That’s because, alluring though the promise of eradicating malaria might be, neither science nor society has quite reached a consensus about when or how creatures with manipulated DNA should be released into the wild — or indeed, what will happen when they are. 
 
 “[Gene editing] is a little bit like geoengineering,” MIT researcher Feng Zhang told the New Yorker earlier this month. “Once you go down that path, it may not be so reversible.” 
 
 Zhang, a biological engineer, led the first team of researchers to employ the CRISPR-Cas9 editing technique on human cells. 
 
 The research out of California was led by UC-Irvine molecular biologist Anthony James and UC-San Diego biologists Ethan Bier and Valentino Gantz. 
 
 James specializes in engineering “anti-disease” mosquitoes, with which he hopes to halt the spread of disease without killing off the world’s bug population. For the PNAS paper, he developed a gene that spurs mosquitoes’ antibodies to attack the malaria parasite (which they acquire while biting infected humans), preventing them from passing the microbe to their offspring. He tested the new gene on the eggs of an Indian mosquito species Anopheles stephensi — that way, if the bugs somehow escaped, they’d find themselves on a foreign continent with an inhospitable climate and no one to mate. 
 
 Bier and Gantz contributed the second part of the potent anti-malaria package. The pair, which effectively introduced a gene drive into fruit flies earlier this year, teamed with James to plug the tool into A. stephensi DNA. They coupled the malaria resistance gene with one that makes mosquitoes’ eyes red, so they could measure whether the resistance gene was passed on. Nearly 100 percent of the offspring had red eyes — and, presumably, malaria resistance. 
 
 “This is a significant first step,” James said in a University of California press release. “We know the gene works. The mosquitoes we created are not the final brand, but we know this technology allows us to efficiently create large populations.” 
 
 James is a member of the National Academy of Sciences, which has convened a committee to review the ethical implication of gene editing and gene drive research. In the meantime, the scientists using CRISPR worry that an accident might undermine their technique before they have a chance to demonstrate its power. 
 
 “If anyone messes up and a gene drive gets out into the wild, there will be a huge media circus,” Esvelt told Nature earlier this month, before the release of the mosquito study. “The message will be that scientists cannot be trusted to deal with this technology, and we will be set back by years.” 
 
 In a study published last week, Esvelt and his colleagues at several Boston universities unveiled a gene drive “safeguard” that can override the initial mutation in yeast cells. 
 
 James told the New York Times that the UC researchers plan to move slowly and very carefully forward with their research. 
 
 “This is the kind of technology where the first trial has to be a success,” he said. 
 
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– How do you get rid of a population of bugs destroying your crops? Scientists are trying out a controversial method: spreading a gene that prevents females from reproducing. Males can live with the lab-inserted gene, but females die in the larval stage—which doesn't leave a lot of options for reproduction or the future of the species, New Scientist reports. In a lab experiment, this decimated the population in 10 weeks. Scientists at English firm Oxitec want to try their method in Spain, where they're awaiting the OK from Spanish authorities to kill off certain fruit flies that destroy some 15% to 30% of the olive tree crop each year. But genetic science watchdogs have concerns about the method, fearing, for instance, that altered populations could affect creatures outside their own species, Mashable reports. A similar experiment is already happening in the wild in Brazil, where the Oxitec team has altered males of a population of dengue-carrying mosquitoes. Some 96% of dengue mosquitoes around the city of Mandacaru have been destroyed, the company says.