The pink grass worm, Tmetolophota atristriga (Walker) (Lepidoptera: Noctuidae), is a New Zealand native species. It is abundant throughout the North and South Islands and is considered a minor pest, defoliating pastures in New Zealand. With changes in farming practices along with climate change, the pest status of insects can rapidly change. Sex pheromones are being used for monitoring and control of insect pests and provide many advantages over the use of pesticides, being species-specific, non-toxic and leaving almost no residue. The identification of the sex pheromone for T. atristriga will enable the development of lures to identify the spread of this pest and offers a potential means to monitor pest populations reaching an action threshold. As such, the T. atristriga sex pheromone could be a key tool in the future for the control of sudden or sporadic outbreaks of this pest.