Field trials of the sex pheromone of an important and potentially invasive pest of avocados, Persea americana Miller (Lauraceae), Stenoma catenifer Walsingham (Lepidoptera: Elachistidae), were carried out in commercial avocado orchards in Guatemala. The results indicated that the pheromone consists of a single component, (9Z)-9,13-tetradecadien-11-ynal; blends of this compound with a range of ratios of the corresponding alcohol and acetate, or with (6Z,9Z)-tricosadiene, which was present in pheromone gland extracts, were equally or less attractive to male moths than the single component. A range of doses from 10 µg to 1 mg were equally attractive, and lures remained attractive for periods of several weeks. Male moth flight activity peaked between 0230 and 0430 hours. Overall, trap catches were relatively low, similar to what was reported for the congeneric Stenoma cecropia Meyrick, suggesting that this species may use other signals in addition to pheromones during mate location. Nevertheless, the pheromone will be useful for detection of S. catenifer, particularly in areas where there is a risk of the moth invading and establishing due to increased commerce in fresh avocados, and for certifying export orchards as being free of S. catenifer.