Most methods that farmers follow today to control pests and save their crop are mostly reactive, which is done ‘after’ the damage has started. In addition, these methods either destroy other crops, or cause harm to animals that feed on them, or pollute the soil or air. Researchers have now found a ‘green’ and ‘clean’ way to detect crop pests before they start the damage. They have built a highly sensitive sensor that detects pheromones or chemicals released by insects for mating, which signal the presence of pests and thus prompt the farmers to take remedial measures.