Gymnandrosoma aurantianum (Lepidoptera: Tortricidae): Calling Rhythm and Effect of Age on Female Sex Pheromone Titer and Male Antennal Responses

The macadamia nut borer, Gymnandrosoma aurantianum Lima (Lepidoptera: Tortricidae), is the main pest of Macadamia integrifolia Maiden & Betche (Proteales: Proteaceae) in Central America. Despite its importance, there is little information on its reproductive behavior. We studied the calling behavior and effect of age on female sex pheromone production and male antennal response to the pheromone. Calling behavior of G. aurantianum females occurred at the onset of scotophase, between 17:00 and 20:00 h. The mean time spent calling was 64 min. It was observed that 30% of the 50 females exhibited a calling posture characterized by extrusion of the pheromone gland from the tip of the abdomen and they spread their wings slightly. Female age had no influence on the sex pheromone production, while male antennal response increased with age and pheromone dosage. The information obtained in this work contributes to understanding the sexual behavior of G. aurantianum and thus to the creation of strategies to control this important pest in macadamia.