Abstract: 【Aim】 Western flower thrips, Frankliniella occidentalis, is a worldwide invasive pest causing devastating damage on crops. Now it becomes a big threat to vegetable and ornamental industry in China. In order to establish the basis of using aggregation pheromone to monitor and control this pest, the mating activity, the female-male interaction and release rhythm of aggregation pheromoneofmaleadultsof F. occidentalis during photophase were investigated in this study. 【Methods】 The mating behavior of F. occidentalis adults was tested using single pair mating and group mating methods, the female-male interactions were observed under video system, and the release rhythms of aggregation pheromone in male adults were analyzed at four time (the 1st, 4th, 8th and 12th hour) of photophase using solid phase micro-extraction and gas chromatography-mass spectrometry. 【Results】 The mating percentages, mating duration, femalemale interaction repeats and male harassment repeats of F. occidentalis adults at the four time of photophase were not significantly different, suggesting that the corresponding behaviors are arrhythmic during photophase. The release rhythms of the attractive aggregation pheromone component neryl (S)-2-methylbutanoate were in accordance with the behavior pattern, without significant difference at the four time of photophase. However, the release rates of unattractive aggregation pheromone component (R)-lavandulyl acetate were significantly different at the four time of photophase. 【Conclusion】 The study confirmed that the mating activity, female-male interaction and the release of the attractive aggregation pheromone component neryl (S)-2-methylbutanoate of F. occidentalis adults are arrhythmic during photophase. These results provide a theoretical basis for understanding the behavioral function of aggregation pheromone compounds and a guide for population monitoring and pest control of thrips using aggregation pheromones in the field.
 

Key words: Frankliniella occidentalis; mating behavior, female-male interaction, aggregation pheromone, release rhythm