Abstract: 【Aim】 Brithys crini mainly damage Lycoris plants. The aim of this study is to understand the circadian rhythm of calling behavior of B. crini and identify the sex pheromone components of its female moths, so as to provide the theoretical basis and technical guidance for the application of sex pheromones in green control of B. crini. 【Methods】 The virgin female moths of B. crini were placed individually in a plastic cup and their calling behavior was observed every 0.5 h. The start and end time of calling, and courtship duration of each female moth at different day-old were recorded. The sex pheromone gland of virgin female moth was extracted using distilled hexane extraction. The active component of sex pheromone gland extracts was screened by gas chromatography-electroantennagram detection (GC-EAD) and gas chromatography-mass spectrometry (GC-MS), and its titer (content) was further determined by GC-MS. The electrophysiological activities of sex pheromone components to the antennae of male moths were measured by electroatennogram (EAG) apparatus. 【Results】 The peak calling period of the female moths of B. crini was between the 3.5 and 9.0 h into scotophase, and the 1-day-old female moths displayed the highest calling rate. The calling rates of the 1-2-day-old female moths were significantly higher than that of the 3-day-old female adults. GC-EAD results showed that a component of the sex pheromone gland extracts could induce EAG response of male moths. The active component was identified as (Z)-11-hexadecenal (Z11-16∶Ald) by GC-EAD analysis and Kováts retention index. And the average titer of Z11-16∶Ald in the sex pheromone glands of the 1- and 2-day-old female moths was (3.11±0.01) ng by external standard method. EAG test data showed that different doses of Z11-16∶Ald could evoke different EAG responses in male moths of B. crini, and when the dose of Z11-16∶Ald was 100 ng, the EAG response was the strongest. 【Conclusion】 The 1-day-old female moths of B. crini show the most active calling behavior, and the peak calling period of female moths is between the 3.5 and 9.0 h into scotophase, and the major sex pheromone component of female moths was identified as Z11-16∶Ald.

Key words: Brithys crini, calling rhythm, sex pheromone, identification; Z-11-hexadecenal, electroantennogram (EAG)