Abstract: 【Aim】To explore the feasibility and theoretical basis of using sex pheromone and floral scent trapping as monitoring methods for Loxostege sticticalis adults. 【Methods】The developmental status of female ovaries and male testes of L. sticticalis moths trapped by sex pheromone, floral scent and net catching were investigated, dissected and analyzed in the field, and the relationships between the egg quantity, number of trapped moths and the number of field survey populations, and the migration status were analyzed. 【Results】The testes of male moths of L. sticticalis were closely related to the day-old age, and the regression equation was y=1.289-0.1288x+0.003516x2. Field experiments conducted in Kangbao, Hebei during 2020-2023, revealed that when sex pheromone traps successfully captured male moths, the mating rates of female moths were 66.7%-100%, and the proportions of level Ⅳ ovaries were 44.1%-95.4%. When the male moths could not be trapped, the mating rates of female moths were 0%-30.3%, and the level Ⅳ ovaries accounted for 0%-3.6%. From June 12 to June 22, 2024, the average mating rate of female moths trapped by floral scent (94.3%±2.3%) was significantly higher than that of female moths trapped by net catching (76.2%±5.3%) in Dashimen Town, Hexigten Banner, Inner Mongolia Autonomous Region. There was no difference in the average number of matings between female moths trapped by floral scent and by net catching. The number of egg grains remaining in the ovaries of female moths trapped by floral scent was (169.8±15.4), which was significantly lower than the that of female moths trapped by net catching (267.9±20.7). The average testicular volume of the male moths caught by sex pheromone trapping was the largest ［(0.21±0.01) mm³］, followed by that trapped by net catching ［(0.19±0.02) mm³］, and that trapped by floral scent was the smallest ［(0.15±0.01) mm³］. The number of L. sticticalis adults trapped by sex pheromone and floral scent was closely related to their physiological state. Adults attracted by sex pheromone were male moths searching for mates, while those caught by floral scent trapping were female moths which have mated and laid part of eggs, as well as male moths which have mated. Therefore, male moths of the immigrant population and local breeding population of L. sticticalis were sensitive and had strong responses to sex pheromones, while the ovarian development level of female moths of the emigrant population was low, and the corresponding male moths were immature, and had no olfactory behavioral response to sex pheromones and floral scent. This relationship was verified by multiple field experiments in different seasons in Kangbao, Hebei and Hexigten Banner, Inner Mongolia from 2020 to 2024. 【Conclusion】 The combination of sex pheromone trapping and floral scent trapping can help determine the physiological state of L. sticticalis and estimate its migratory status and population dynamics of the next generation in the field.

Key words: Loxostege sticticalis, reproductive system, sex pheromone trapping, floral scent trapping, ovary, testis, migration