Abstract
Unmated female A. kühniella (Zell.) emitted a sex pheromone at the beginning of the light period of a 24 hour cycle of light and dark periods. There were no differences apparent in the duration of the calling posture by females in light of 1, 40, or 200 lux. A sex pheromone was extracted from the abdominal tips of unmated females of various ages with organic solvents, 3-day-old females gave the most potent extracts. Extracts of equal potence were obtained from females at different times during the diel cycles of photoperiod. The response of males to the extract was maximal at dawn, increased with age for 5 days, and was greater in light of 1 lux intensity than of 200 lux. Both sexes showed an anticipation of the beginning of the light period in their sexual behaviour, but if the timing of the cycle of photoperiod was changed the behaviour of both sexes became synchronised to the new cycle on its second or third occurrence.