March 4, 1993 Nerolic and geranic acid are geometric isomers of 3,7-Dimethyl-2,6- octadienoic acid. The most common synthesis produces a mixture of both isomers, and in fact, the nerolic acid in the Winston et al. paper also contained geranic. Nerolic acid is more active as an orientation pheromone, but having geranic acid with it does not reduce efficacy. Nerolic/geranic acid are not readily available. They have been obtained from custom chemists, and might become commercially available soon. Call Justin Schmdit - USDA, ARS at (602) 670-6380 for the latest information. Jose Villa