柑橘大实蝇直肠粗提物的信息素功能

【目的】确定柑橘大实蝇（Bactrocera minax）成虫的性成熟时间；获得柑橘大实蝇成虫的直肠粗提物并分析其信息素活性。【方法】在显微镜下解剖观察成虫直肠的形态及其在消化道内的位置；用正己烷分别对5、10和15 日龄的雌、雄柑橘大实蝇成虫直肠（含直肠腺）和躯体（除去直肠）进行提取，利用触角电位技术和田间诱集试验对粗提物的信息素活性进行测定。【结果】消化道解剖发现，柑橘大实蝇直肠位于消化道末端，前部连接后肠，后部连接肛门，形态上与同属的其它实蝇类似。触角电位试验表明，雌、雄成虫触角分别对15日龄异性直肠粗提物产生显著的EAG反应，同时，雌、雄触角对同性的直肠粗提物也有一定的反应。田间诱集试验结果表明，在诱虫数方面，15日龄雌性直肠粗提物的平均诱虫数最高，显著高于水解蛋白诱饵、糖醋酒液以及雄性直肠粗提物。另外，雄性直肠粗提物也诱集到少量成虫。在诱集虫口的雌雄性比方面，15日龄雌性直肠粗提物诱集虫口的雌雄性比为0.82﹕1，而水解蛋白诱饵、糖醋酒液以及雄性直肠粗提物所诱集到的则主要是雌虫。【结论】柑橘大实蝇成虫在羽化后15 d左右达到性成熟，其直肠的形态和位置均与同属的其它实蝇类似，同时，柑橘大实蝇成虫的直肠（含直肠腺）具有分泌和储存信息素的功能。其中，柑橘大实蝇雌性直肠粗提物中含有能够吸引雌性和雄性个体的信息素活性物质。

Pheromonal Activity of Rectum Extracts from Chinese Citrus Fly (Bactrocera minax)

【Objective】The objective of this study is to make clear days that emerged adults of Chinese citrus fly (Bactrocera minax) need to reach sexual maturity, to obtain rectum extracts from adults fly and assay their pheromonal activity.【Method】Under a microscope, morphology and relative location of rectum in digestion system of adult flies were observed. Rectums from both males and females of 5-, 10- and 15-day-old adult flies were extracted with n-hexane. Male and female bodies with rectum excised were also extracted. EAG responses of male and female adults to rectum extracts and body extracts were recorded. Field attractiveness of rectum extracts from 15-day-old male and female adults were also investigated. 【Result】The rectum of B. minax was located at the distal part of digestion system, between hind gut and anus. The rectum was morphologically similar as that of other species in Bactrocera. EAG responses of male and female adults to heterosexual rectum extracts were the highest among all extracts. Meanwhile, male and female adults also showed relatively high EAG responses to homosexual rectum extracts. In field tests, 15-day-old female rectum extracts attracted significantly more adults than any one attractant of hydrolyzed protein lure, sugar solution with wine and vinegar mixture, and 15-day-old male rectum extracts. Meanwhile, even attractiveness of 15-day-old male rectum extracts was much lower than that of 15-day-old female rectum extracts, male rectum extracts still attracted a small number of adults. Sex ratio of adults attracted by 15-day-old female rectum extracts was 0.82﹕1, while any of other attractants attracted more females than males. 【Conclusion】About 15 days after emergency, Chinese citrus flies reaches sexual maturity. With similar morphology and location in digestion system as other species in Bactrocera, the rectum of B. minax also probably secrets and stores pheromonal substances in its rectal gland. Moreover, pheromones in female rectum are attractive to male and female adults in the field.