Observation of courtship behaviors mediated by a female sex pheromone in the pear barkminer moth, Spulerina astaurota (Meyrick) (Lepidoptera: Gracillariidae)

Abstract

Courtship behavior of the pear barkminer moth, Spulerina astaurota (Meyrick) (Lepidoptera: Gracillariidae), was investigated under laboratory conditions. Female moths showed a calling posture, i.e. exposing abdominal tips with the wings raised, mainly in the middle of the scotophase. Mean mating duration of 26 pairs was 82.9±5.0 min. Males responded to virgin females by showing a series of six behavioral components; orientation walk with fierce antennal swing (OW), orientation flight (OF), landing on female (LF), touching a female's abdomen (TF), abdominal contact (AC) and copulation (CP). One female equivalent of a crude pheromone extract and several doses of a synthetic pheromone universally elicited OW, OF and LF in 1-day-old and older males, mainly 4.5-7.5 hours after lights off, but 0-day-old males mainly showed these mating behaviors at and after 6.5 hours after lights off. While a similar frequency of OW, OF and LF was observed at various doses of the synthetic pheromone, the response of some males exposed to 10 and 100 ng synthetic pheromone stopped at the OW.