Sex pheromones mediate mate location in many animal taxa. Widow spider males are attracted to sex pheromones disseminating from female webs. Upon arrival on a web, males court in response to web-borne contact pheromone components. N -3-Methylbutanoyl- O -methylpropanoyl-L-serine methyl ester ( 1 ) is the single known, weakly effective, contact pheromone component of female western black widows, Latrodectus hesperus. Moreover,...