Abstract: 【Aim】To study the effects of allicin E (ALE) on the oviposition behavior of Drosophila suzukii, and to provide a reference for the biological control of D. suzukii by ALE. 【Methods】The avoidance effects of 0.01%， 0.015% and 0.02% ALE on the oviposition of D. suzukii female adults were detected with oviposition two-choice device. The effects of sensory systems of vision, gustation and olfaction on the oviposition preference of female adults of D. suzukii were investigated by means of darkness, surgically removing the forelegs and antennae, respectively. The avoidance effects of 0.015% ALE on the oviposition behavior of female adults of D. suzukii were tested by Y-maze experiment. The effects of ALE on the fitness of D. suzukii were tested by determining the survival rate and developmental duration. The reactive oxygen species (ROS) level in the intestines of D. suzukii adults treated with ALE was detected by fluorescent staining. 【Results】ALE had avoidance effects on the oviposition of female adults of D. suzukii, and the oviposition indexes to 0.01%, 0.015% and 0.02% ALE were -0.30, -0.44 and -0.51, respectively. In darkness and forelegless groups, the female adults of D. suzukii still showed significant oviposition avoidance to ALE. However, the female adults of D. suzukii with antennae removed had significantly decreased oviposition avoidance to ALE, and the oviposition indexes to 001%, 0.015% and 0.02% ALE were decreased to -0.10, -0.11 and -0.12, respectively. After the eggs laid by female adults of D. suzukii were exposed to 0.02% ALE, the offspring pupal and adult survival rates were decreased by 69.23% and 69.70%, respectively, and the time to puparium formation and time to adult eclosion of offspring were prolonged by 5.88 and 4.75 d, respectively. ALE shortened the adult life span of D. suzukii, and the LT₅₀ values of females and males under 0.02% ALE treatment decreased from 39 d to 18 and 15 d, respectively. The running and climbing speeds of D. suzukii adults were significantly decreased at 72 h after treatment with 0.02% ALE. The ROS levels in the intestine of D. suzukii adults were increased at 3 d after treatment with 0.02% and 0.05% ALE. 【Conclusion】ALE induces oviposition avoidance in female adults of D. suzukii, which is mediated mainly by olfaction. ALE prolongs the growth and development of the offspring of D. suzukii, decreases the locomotion performance and the survival rate of adults, and causes intestine damage in adults, thereby having potential biological control value against D. suzukii.

Key words: Drosophila suzukii; allicin E, oviposition avoidance, olfactory system, reactive oxygen species