The plant bug, Apolygus lucorum Meyer-Dür, has begun to resurge and become a key pest in cotton in northern China, along with the wide-scale adoption of transgenic Bt cotton. To control this plant bug, we attempted to develop a new approach by identifying and utilizing its sex pheromone.Extracts from A. lucorum adults and nymphs were analyzed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-electroantennogram detector (GC-EAD) to identify the sex pheromone components. (E)-4-Oxo-2-hexenal and (E)-2-hexenyl butyrate were the major components from females and were also the electrophysiology-active components to male antennae. For males, (E)-4-oxo-2-hexenal and hexyl butyrate were the major components. These three components, however, were not detected in nymphs. Field tests showed that binary blends of (E)-4-oxo-2-hexenal and (E)-2-hexenyl butyrate at a ratio of 3:2 resulted in the trapping of the greatest numbers of A. lucorum males. A long-term dispenser was developed by loading the pheromone components dissolved in sunflower oil into PE vials. Further field evaluation showed that the PE dispensers attracted significantly more bugs even when they were deployed in the field for 5 weeks.We identified the sex pheromone of A. lucorum and developed a type of high-efficiency and long-term lure. Our results could expand the knowledge of the pheromones of plant bugs, and provide novel technologies to monitor and control this pest. This article is protected by copyright. All rights reserved.