Marmara gulosa Guillén & Davis (Lepidoptera: Gracillariidae) is a sporadic pest of citrus and a number of other crops in southern and central California. Coupled gas chromatographic-electroantennogram detection analyses of headspace volatiles collected by solid phase microextraction from virgin female moths revealed at least four related compounds in the extracts that elicited significant antennal responses from antennae of male moths. These compounds were identified as (8E,10E)-tetradecadien-1-ol, and the corresponding aldehyde, acetate, and formate ester, representing the first report of a formate as a lepidopteran pheromone component. The four compounds were consistently found in headspace volatiles collected from virgin female moths from different regions of the state and from M. gulosa collected from different host plants (citrus and squash). Repeated field trials determined that the formate ester alone was as attractive or more attractive than any blend of the formate with one or more of the remaining compounds. Although large numbers of moths were caught in some field trials, trap catches were not consistent. Thus, the pheromone may be useful for detection of the moth and setting an initial biofix, but it remains unclear whether the pheromone can be used as a reliable and accurate tool for monitoring densities of M. gulosa populations.