Electroantennogram analyses of female gland extract and of male antennal responses to synthetic standards suggested that (Z,E)-3,5-tetradecadien-1-ol acetate is a pheromone component for the carpenterworm moth,Prionoxystus robiniae (Peck). The four 3,5-geometrical isomers were synthesized and bioassayed in the laboratory and the field in 1972, 1973, and 1974. TheZ,E isomer was found to be active in the laboratory and a good attractant in the field. The synthesis of theZ,E isomer also produced considerable quantities of theE,E isomer, which is difficult to remove completely. TheE,E isomer does not inhibit the response of males to theZ,E isomer when it is present in amounts up to 20% of theZ,E isomer. The addition of a keeper, a volatility modifier, or an antioxidant prolonged the activity of the attractant for as much as 43 days. (Z,E)-3,5-Tetradecadien-1-ol acetate may be a natural pheromone, but it has not been chemically defined from female extract. There is EAG evidence that a second pheromonal component may be present. The attractant nevertheless provides a tool for population survey, behavioral studies, evaluation of economic impact, and possibly control.