桔小实蝇雄成虫联系性嗅觉学习

Associative olfactory conditioning in male adults of the oriental fruit fly,Bactrocera dorsalis( Diptera: Tephritidae)

【目的】为了探究桔小实蝇Bactrocera dorsalis(Hendel)雄成虫的嗅觉学习能力。【方法】本研究采用经典性嗅觉条件反射训练法(classical olfactory conditioning)在室内对固定的羽化后14-17日龄的桔小实蝇雄成虫进行气味与食物的联合学习训练,即薄荷精油和10%蔗糖溶液联合的奖赏性训练(appetitive conditioning)以及甲基丁香酚(methyl eugenol,ME)和饱和盐溶液联合的惩罚性训练(aversive conditioning),并以伸喙反射行为(proboscis extension reflex,PER)作为学习与否的判定标准。【结果】经过奖赏性训练后,桔小实蝇雄成虫对薄荷精油的伸喙反射率可从0%增加至68%;而经过惩罚性训练后,桔小实蝇对甲基丁香酚的伸喙反射率可从100%降低至36.54%,且这种伸喙反射率的变化是通过气味条件刺激(conditioned stimulus)和食物非条件刺激(unconditioned stimulus)的对称性联合而产生的。【结论】结果表明,桔小实蝇雄性成虫具有较强的联系性嗅觉学习能力,并且两种刺激的联合是形成学习记忆的必要条件。

【Aim】This study aims to explore the olfactory learning capability of the male adults of the oriental fruit fly,Bactrocera dorsalis（ Hendel）. 【Methods】A classical olfactory conditioning procedure was adopted. The 14- 17 day-old male adults of B. dorsalis were individually trained to associate odor with food in the laboratory,i. e.,exposed to peppermint odor paired with 10% sucrose solution for appetitive conditioning and methyl eugenol（ ME） paired with saturated salt solution for aversive conditioning. The change of the proboscis extension reflex was used as the criterion for conditioning.【Results】The proportion of proboscis extension reflex of male adults of B. dorsalis increased from 0% to68% after appetitive conditioning,and decreased from 100% to 36. 54% after aversive conditioning.And its variation was generated by a temporal relation between odor conditioned stimulus（ CS） and food unconditioned stimulus（ US）（ paired）. 【Conclusion 】These results indicate that male adults of B.dorsalis have a strong capacity to form an olfactory memory as a result of classical conditioning,while the contiguity of CS and US is a necessary condition of learning.