Abstract: 【Aim】To make better use of sex pheromones in the monitoring and control of the tomato leafminer, Tuta absoluta, and to further study the circadian rhythms of its movement, calling and mating behavior. 【Methods】For T. absoluta adults, video recording and two-dimensional trajectories were used to analyze their movements. Solid-phase microextraction (SPME) adsorption extraction and gas chromatography-mass spectrometry (GC-MS) were used to analyze the sex pheromone titer in female adults. In tomato greenhouses in Xichang City, Sichuan Province from August to September 2022, field trapping experiments were carried out to analyze the relationship between the sex pheromone titers of T. absoluta adults and their day-old age and circadian rhythm based on the trapping results. The mating behavior was observed in indoor insect cages, and the reproductive system of the male adult was observed by dissection, and the relationship between development and day-old age was analyzed. 【Results】The results showed that in the indoor natural environment, the movement of female and male adults occurred from the 5th hour of the scotophase to the 2nd hour of the photophase, with the peak at the 5th to 7th hour of the scotophase, and there was no significant difference in the time and distance of movement between females and males, and between the 1-7-day-old assayed. The sex pheromones of T. absoluta can be detected in adults at the 1-11-day-old, but there was no significant difference in the sex pheromone titer between day-old ages. The sex pheromones released by female adults were detected during the entire 24 h period, and the difference in the sex pheromone titer between different periods was not significant. Mating did not significantly affect the sex pheromone titer in female adults. However, the male adults in the field were trapped from the 7th hour of the scotophase to the 2nd hour of the photophase. T. absoluta adults were able to mate on the same day of emergence, and the mating rate was the highest when the male adults were at the 3-day-old, and then decreased, but there was no significant difference in the mating duration between day-old ages. The peak time of mating occurred at the 7th and 10th hour of the scotophase, and there was no new mating after the photophase. The testicular volume of male adults decreased as the day-old age increased, and based on the testicular volume of male adults caught by sex pheromone trapping, it was calculated that the age of those trapped males was 3-7-day-old. 【Conclusion】The calling and mating time of T. absoluta adults occurred at the end period of the scotophase. The sex pheromone titer of female adults remained at a consistently high level at different day-old ages and circadian rhythms, and mating did not significantly affect sex pheromone titer, resulting in older male adults being caught by pheromone trapping, and their testes were the same size as those of the 7-day-old male adults, and most of them may have already mated. The data here give a more clear description of the calling and mating behavior of T. absoluta adults, thus, they can provide technical bases and parameters for the development and application of mass trapping and mating disruption by sex pheromones.

Key words:  Tuta absoluta, movement, calling behavior, mating, age, dircadian rhythm