In the United States, the first genetically modified male cabbage moth butterflies were released into nature, writes the journal Frontiers in Bioengineering and Biotechnology.
Cabbage moth (Plutella xylostella) is one of the main crop pests in the world. The larvae feed on the leaves of cauliflower and white cabbage, broccoli and rapeseed. The insect adapts surprisingly quickly to all new types of pesticides. The annual damage caused by the cabbage moth is estimated at $ 5 billion a year.
Thanks to the biotechnological development of American and British scientists led by Anthony Shelton, the number of agricultural pests will decrease.
Experts have added two new genes to the natural moth. One of them is included only in the offspring of genetically modified (GM) males, leading to the death of all newborn females. Moreover, such a gene is transmitted through the male line, and all males born from GM insects will also not be able to have female offspring.
Another gene, encoding a red fluorescent protein, was needed only to identify GM moths in nature.
The model developed by scientists is manageable and self-limiting. Since the offspring of the cabbage moth has a high mortality rate - up to 50 percent of each new generation dies - according to the calculations of scientists, the lethal gene will disappear in several generations if new GM males are not released each time.
How were the tests
During field trials in New York State in August and September 2017, researchers released GM moths six times, ranging from 1,000 to 2,500 each. According to the observations of scientists, GM males in the first season survived in the wild and successfully competed with wild males for mating with females.
As expected, within several generations, GM insects on the territory completely disappeared. To control the release of the artificial strain from the local ecosystem, the researchers used the mark - release - recapture technique, when tagged moths, attracted by special pheromones, were collected in traps.
Neil Morrison, head of the British research center Oxitec in the field of agriculture and one of the authors of the study, noted that the study showed the enormous potential of such technology as a pest control tool.