Pheromones are the chemicals insects use to communicate. Now the renowned Rothamsted Research have come up with a no parking sign on wheat that prevents the dreaded wheat bulb fly and the cereal aphid from landing on the crop. In the UK alone, the wheat crop is worth £1.2bn each year. Without expensive pesticides, aphids would waste about at least 12%.
Always the farmers' friend, Rothamsted in Hertfordshire, England, has been in business longer than research itself! GM critics might moan, but helping the world's food crisis is more important than those who understand little about the science that alleviates it. The gene from a peppermint makes the wheat smell bad to the greenfly (though doesn't smell of peppermint to us.)
Professor Maurice Moloney, director of Rothamsted Research, has described the insects as a "ten billion dollar problem". "Generally, GM has been used to kill something," he explained. "You've either got to kill the weeds or you kill the insects. In this case we're copying nature. What we're really doing is putting a no-parking zone on every leaf of the plant saying: 'Don't come here, because this is not a place you want to be."
He has begun a project this week, on eight square plots, that checks the progress of the seedlings as they are exposed to attack by the brown bandits. Lab. studies have already shown that the attack is successfully repelled by using a natural repellent in an unusual context. If scientists use this aphid alarm pheromone, it will deter large numbers of aphids and also attract parasitic wasps.
Wheat image via Shutterstock
The wasps have naturally evolved to detect the aphid pheromone too. It's a double whammy for farmers, because the wasps emerge over the horizon just as the few remaining greenfly think they could still win. But the insect reinforcements seem to win the day for farmers in such a way that they can't lose. Aphids of course penetrate the phloem of the wheat's transport system, allowing viruses such as BYDV to spread in the crop. Yes, that's been a treble protection for the crop!
However, with EU problems in adopting GM (apart from some pig-food in Spain), objectors are also having their say: GM Freeze are quoting their concerns. "There's already evidence from biological studies that if you expose aphids to this particular pheromone for any length of time they get habituated to it and ignore it. Insects adapt quite quickly." However, the fly has not yet adapted to its own alarm signal, after millions of years!