The teak skeletonizer, Eutectona machaeralis (Walker) (Lepidoptera: Crambidae), is a primary pest of teak trees in plantations and natural forests. However, the biology of this pest is not well studied. We investigated adult emergence, calling behavior, and circadian rhythm of sex pheromone production of this moth in the laboratory. Adult emergence only occurred during scotophase, when females emerged faster than males. Females initiated sexual calling behavior starting 1 d after emergence. This behavior then peaked on the second day of emergence. Sex pheromone release peaked 7 h into scotophase, wherein 2-d-old females elicited the strongest male antennal response to this substance. Our results provide a basis for future investigations of E. machaeralis sex pheromone production that may lead to development of novel methods to control this forestry pest.