Millions of mosquitoes are bred in a laboratory where the male pupae are sorted out and sterilized. The method is not new, but has previously required large manual resources. Now researchers have developed an automatic “puppy sorter” that makes the work significantly easier and faster. A single person can operate several machines at the same time, which can produce up to 16 million sterile male mosquitoes per week, write the Chinese researchers behind the study, published in the scientific journal Science robotics. The researchers found in their experiments that the number of mosquitoes was greatly reduced, as the females that mated with the sterilized males did not have any offspring. Our mission includes finding alternative pesticides, so this is clearly interesting, says Martina Schäfer, pest control manager at the Biological Mosquito Control project. “Difficult in Sweden” But mosquito expert Anders Lindström at the Norwegian Veterinary Institute (SVA) is not as convinced as to whether the method can be effective in Sweden. At least not when it comes to the flood mosquito, which creates major problems for people and animals in above all the areas around the Dalälven. It cannot be propagated in the laboratory and also has a tendency to move on to new areas. So even if it could be propagated, it would be difficult to know where to release the sterilized male mosquitoes in that case, he says. It is unclear why the flood mosquito cannot be propagated in the laboratory. Some mosquitoes have specific requirements for mating sites, such as wanting to swarm around bushes at dusk, says Anders Lindström. So far, it has not been possible to create a laboratory environment that makes these mosquitoes feel compelled to mate. In addition, it would require “astronomical amounts” of mosquitoes to achieve results, according to Lindström. Invasive species It could, however, be helpful against invasive mosquito species such as the cemetery mosquito and the tiger mosquito, he adds. The cemetery mosquito, which dwells precisely in cemeteries, in parks and in residential areas where there are a lot of people, could become a problem in the future. Here the method might work. Biological mosquito control has long advocated the use of the method with sterile male mosquitoes, but according to Martina Schäfer, has so far had difficulty getting the authorities to listen – and the resources that would be required.
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