(CN) – Scientists have conducted the first successful field release experiment of a genetically modified moth that could fundamentally change how crops are protected from pests.
The study, published in the scientific journal Frontiers in Bioengineering and Biotechnology, reveals that scientists at Oxitec have created a new type of diamondback moth – species often referred to as the “cabbage moth” due to their gluttonous and uninvited consumption of a number of crops such as broccoli and cabbage, that has been genetically modified to help control population numbers in any given field.
Researchers accomplished this by outfitting male diamondback moths with a special “self-limiting gene” that, after a male has mated with a female and has passed on to its offspring, prevents the female offspring from surviving the caterpillar stage.
The study suggests that releasing the genetically modified moths into certain areas can be done in controlled and responsible intervals, and that once the genetically modified moths are no longer released, the self-limiting moths will eventually disappear naturally from the environment after several generational cycles.
Researchers believe that their successful test release of these genetically altered moths could profoundly change crop management as we know it today, providing an effective tool to control population levels of an insect that has caused billions of dollars in damage to crops, and a safer alternative to pesticide and insecticide sprays to which many diamondback moths have already started to develop a special resistance.
Anthony Shelton, lead author of the study and a professor in the Department of Entomology at Cornell University's AgriTech in New York, says that one of the strengths of this approach to crop management and protection is found in how many ways it can be used.
“The beauty of this self-limiting technology, besides it being species-specific and environmentally safe, is that it can be used in a variety of ways,” Shelton said. “It can be deployed on a field by field basis, or it can be applied over a large geographic area to control or prevent a pest outbreak. It is also compatible with other tactics such as enhancing biological control by natural enemies, or as a way to manage a pest population while simultaneously reducing the incidence of resistance to particular insecticides.”
The study reports that after releasing the new diamondback moths into an open field and using fluorescent powder to distinguish the genetically altered variants, researchers observed that the newly introduced moths behaved much like their wild counterparts. Data suggests that their natural behaviors coupled with their self-limiting gene would allow the new moth types to successfully control the pest population over a sustainable period of time.
Shelton says these results are extremely encouraging and greatly suggest that the experiment was a success.
"When released into a field, the self-limiting male insects behaved similarly to their non-modified counterparts in terms of factors that are relevant to their future application in crop protection, such as survival and distance travelled. In laboratory studies they competed equally well for female mates. Our mathematical models indicate that releasing the self-limiting strain would control a pest population without the use of supplementary insecticides, as was demonstrated in our greenhouse studies,” Shelton said with the release of the study.
Researchers say that future experimentation with these modified moths will help to further illuminate the kinds of results this approach to crop management can yield, and content that this approach, taken with care and environmental awareness, could offer some much-needed relief to the crops regularly threatened by these small but determined creatures.