Promising Results in the Fight Against Rice Stem Borer MothsPosted: April 9, 2011
According to the USDA, over 430 million metric tons of rice were consumed worldwide in 2008, making it one of the world’s staple crops. But rice production has historically been threatened by disease and insect pests. Rice is Egypt’s second largest export crop. In Egypt, larvae of the rice stem borer moth (Chilo agamemnon) are major insect pests, which cause yield loss as high as 10 – 30%. Unfortunately, classical rice breeding has not improved resistance to this insect. Additionally, because the moth larva enters the rice stem, it is protected from most applied pesticides.
Since it’s difficult to externally apply the pesticide to the stem borer larvae, Egyptian genetic researcher Reda Moghaieb investigated the possibility of modifying the plant to make its own pesticide. Moghaieb chose a gene from a naturally occurring bacterium (Bacillus thuringiensis). This gene contains the instructions for producing a protein that is toxic to stem borer larvae. Moghaieb reasoned that when the gene was introduced into rice, the plant would produce the protein in cells of the stem, killing stem borer larvae that eat it. The gene was added to rice plants. When borer larvae were fed stems of these plants, the larvae died within four days; some died in only 24 hours. These results suggest that when the Bacillus thuringiensis gene is introduced into rice plants it acts as an effective pesticide against stem borer larvae.
REA Moghaieb. 2010. Transgenic rice plants expressing cry1Ia5 gene are resistant to stem borer (Chilo agamemnon). GM Crops 1:5, 1-6.
International Rice Research Institute has information about rice, its history, and its socio-economic relevance.