Comparative Sex Pheromone-associated Behavior of Planotortrix notophaea and P. octo (Lepidoptera: Tortricidae)

Sex pheromone-associated behavior of two tortricid moths in New Zealand, Planotortrix notophaea and P. octo , was studied in a laboratory. Most males of both species changed their antennal posture responding to the change from light to dark phase. Three antennal postures in both sexes were designated by dorsal view: antennae in resting position, those extended less than 80° from body axis, and those extended more than 80° from the body axis. In P. notophaea , antennal posture of males appeared as an external indicator representing the physiological readiness for pheromone perception; males with antennae extended more than 80° from the body axis responded better than those in resting position. Bioassays with medicine droppers indicated that threshold concentrations for male response to crude female pheromone extract were 3 × 10 −3 female equivalents (FE) and 3 × 10 −7 FE in P. notophaea and P. octo , respectively. In P. octo , threshold concentrations for male response to known pheromone compounds, (Z)-8-tetradecenyl acetate and tetradecyl acetate, were 10 fg and 100 fg, respectively. Female calling appeared continuous rather than being pulsed. In P. notophaea , stronger male responses were elicited toward females with antennae extended more than 80° from the body axis than those in resting position.