关键词:  橘小实蝇, 性二态行为, 甲基丁香酚, 2烯丙基4,5二甲氧基苯酚, 行为反应, 电生理反应

Abstract: 【Aim】The oriental fruit fly (Bactrocera dorsalis), a globally significant pest of fruits and vegetables, has been effectively managed using the male annihilation technique (MAT) based on male attractants, where methyl eugenol (ME) serves as a key lure with potent attraction to males. However, current techniques predominantly target males, leaving the behavioral responses of females to ME and their olfactory perception unclear. This gap has become a bottleneck in the comprehensive optimization of ME-based attractants for females. Therefore, this study aims to systematically reveal the behavioral responses of female adults of B. dorsalis to ME and their olfactory perception capabilities, explore the potential biological roles of ME in B. dorsalis females, and provide new insights for optimizing female-targeted pest control strategies using ME.【Methods】To clarify the responses of female adults of B. dorsalis to ME and their perception capabilities, active 12-day-old female and male adults of B. dorsalis were selected for the subsequent assays. First, olfactory trap experiments and a four-arm olfactometer were used to test the taxis responses to 1 000 and 100 μg of ME and 2-allyl-4,5-dimethoxy phenol (DMP) with similar male-attracting functions, and to evaluate the feeding behavior elicited by 1 000 μg of ME and DMP. Second, the electroantennogram (EAG) responses of B. dorsalis adults to ME and DMP at the doses of 0.1, 1, 10 and 100 μg were recorded in both sexes. Finally, single sensillum recording (SSR) was used to record the SSR responses of basiconic sensilla on the antennae of female and male adults of B. dorsalis to ME and DMP.【Results】Behavioral test results demonstrated that female adults of B. dorsalis displayed neither obvious attraction nor feeding preferences for ME or DMP, in contrast to male adults exhibiting strong behavioral responses. However, EAG experiments showed that female adults of B. dorsalis, similar to male adults, exhibited significant olfactory responses to ME and DMP. Further SSR experiments revealed that female and males adults of B. dorsalis possessed similar olfactory sensilla, responsible for detecting ME and DMP.【Conclusion】The findings suggest that female adults of B. dorsalis have comparable olfactory perception mechanisms to male adults for ME detection. However, the effects of ME on female adult behaviors differ from its strong attraction function in male adults, indicating that ME may have other potential biological roles in female adults. These results provide novel experimental evidence for understanding the perception and behavioral responses of B. dorsalis to ME, while offering theoretical insights for optimizing female-targeted behavioral manipulation technologies.

Key words: Bactrocera dorsalis, sexual dimorphism, methyl eugenol, 2-allyl-4,5-dimethoxyphenol, behavioral response, electrophysiological response