Paul Nelson runs a raspberry farm in the northern U. S. state of Minnesota. Raspberries are a popular red fruit that people like to eat in the summer. However, at the farm, Nelson and his team spend a lot of time worrying about fruit flies.
The flies cause damage by laying eggs in the fruit. Nelson said the flies can ruin fruit farms if farmers are not willing to put the time in to fight them. Farmers use chemicals to kill the flies or place covers over the fruit plants to protect them. It is a lot of work, and even with the hard work, they lose 20 to 30 percent of their crop each year.
Researchers at North Carolina State University are working to solve the problem. In the laboratory, they are changing the DNA of female flies to make sure that any babies they have are not able to reproduce. The scientists published their work recently in a publication called the Proceedings of the National Academy of Sciences. They found that if they mated one of their flies with a normal fly, 99 percent of the later generations would not be able to reproduce. The scientists used computer models to make predictions and found that by releasing modified(改良的) flies over time, they could reduce the population of fruit flies in an area like a farm in only five months.
It is not the first time that scientists have considered modifying the DNA of an insect. Scientists are using genetically modified mosquitoes to reduce the population of the insects that cause diseases such as yellow fever, dengue and Zika. The use of gene modification technology has not been used as often in agriculture because it is easier to use pesticides (杀虫剂). Max Scott, a professor who worked on the study, said past methods for releasing genetically modified insects would be costly for farmers if they were used. However, his group is studying a new method which can reduce the population of fruit flies so fast that it would not cost so much.
