Abstract: 【Aim】 This study aims to illustrate the effects of light intensity on the sexual behavior of the cotton bollworm, Helicoverpa armigera (Hübner). 【Methods】 The calling behavior of H. armigera female adults under four light intensity (0, 0.5, 5.0 and 50.0 lx) was observed. The sex pheromone titer and the incidence of mating of female adults under different light intensity were assayed by pheromone extraction from individual adult and dissection of the bursa copulatrix of female adults, respectively. 【Results】 Under high-intensity light (50.0 lx), the onset time of calling was the latest, the mean duration of calling was the shortest, the mean number of calling bouts was the smallest, the sex pheromone titer remained low during the entire scotophase, and the mating rate was the least. Under low-intensity light (0.5 lx), the onset time of calling was the earliest, the mean duration of calling was the longest, and the mean number of calling bouts was the highest. There were over 40% females calling during the 2nd half of scotophase although the amount of Z9-16:Ald was low under the light of 5.0 lx. 【Conclusion】 High-intensity light (50.0 lx) can suppress the calling behavior, sex pheromone production, and mating of H. armigera adults. Low-intensity light (0.5 lx) can significantly promote female moth calling and mating in a short time (1 h) compared to the dark condition (0 lx). Low-intensity light (0.5 lx) is of significance for sexual behavior of adult H. armigera. Sex pheromone production and calling behavior are not related. This research provides some theoretical basis for the effects of light on the sexual behavior of noctuid moths, and also offer new ideas on taking advantage of physical and chemical communication for control of pest noctuid moths.

Key words: Helicoverpa armigera, light intensity, calling behavior, mating behavior, sex pheromone