云南切梢小蠹对初侵害云南松挥发物的电生理和行为反应

Electrophysiological and behavioral responses of Tomicus yunnanensis to plant volatiles from primarily infected Pinus yunnanensis in Yunnan,Southwest China

云南切梢小蠹Tomicus yunnanensis(Kirkendall and Faccoli)是一种蛀害云南松Pinus yunnanensis的本土害虫。为深入了解其寄主选择机制,用顶空动态法和浸提法分别提取了初侵染云南松针叶和松脂的挥发性化合物,并用气相色谱-质谱联用技术(GC-MS)、气相色谱-昆虫触角电位测量系统(GC-EAD)、生测法鉴定和筛选了对云南切梢小蠹具有活性功能的成分。结果表明:云南松针叶和松脂中共有18种化合物,均为萜烯类物质,但两者化学成分的构成有显著差异。针叶中单萜类占99.98%,主要是α-蒎烯(80.82%)、β-蒎烯(8.78%)、D-柠檬烯(4.77%)、莰烯(2.86%)和β-月桂烯(1.42%),而松脂以单萜类和双萜类为主,前者以α-蒎烯(21.38%)、3-蒈烯(21.42%)和异松油烯(2.78%)为主要成分,后者仅有长叶松酸(51.13%)一种。云南切梢小蠹对α-蒎烯、β-蒎烯、3-蒈烯、γ-萜品烯和4-烯丙基苯甲醚有触角电位反应,其中α-蒎烯、3-蒈烯和γ-萜品烯具引诱作用,4-烯丙基苯甲醚和β-蒎烯则为驱避功能。研究可为开发植物源引诱剂或与性信息素结合进行种群监测和诱杀提供科学依据。

The Yunnan pine shoot beetle,Tomicus yunnanensis Kirkendall and Faccoli(Coleoptera:Scolytinae)is a native bark beetle pest of Yunnan Province of Southwest China that kills healthy Pinus yunnanensis.To better understand the roles of host volatiles in the host tree selection,we used dynamic headspace and solvent extraction to gain the pine volatiles from the needles and resins of P.yunnanensis infected primarily by T.yunnanensis,respectively.We used chromatography-mass spectrometry(GC-MS),coupled gas chromatography-electroantennographic detection(GC-EAD),and bioassay to detect and identify the biologically-active compounds of T.yunnanensis to host pine volatiles.The results showed that pine volatiles from the needles and resins contained 18 compounds totally,as classified into terpenes.The volatile chemical profiles of P.yunnanensis varied significantly within needles and resins by multi-response permutation procedure.Needle volatile compounds were predominant monoterpenes(99.98%),particularly likeα-pinene(90.82%),β-pinene(8.78%),D-limonene(4.77%),camphene(2.86%),and β-myrcene(1.42%).However,resin contained equally both monoterpene and diterpenes in the chemical profiles.The former mainly involved α-pinene(21.38%),3-carene(21.42%),and terpinolene(2.78%).The latter only had a highly oxidized diterpene,palustric acid,reaching 51.13%in relative amounts.In GC-EAD analyses of the headspace of needle and fresh resin,the antenna of T.yunnanensis produced strongly electroantennographic responses to α-pinene,β-pinene,3-carene,γ-terpinene,and 4-allylanisole.Behavioral choice indicated that α-pinene,γ-terpinene,and 3-carene enhanced obviously attraction of T.yunnanensis,and β-pinene and 4-allylanisole displayed repellent response for T.yunnanensis.Plant source attractants and beetle pheromones combined with active host odors may be an indispensable way to monitor and trap T.yunnanensis to achieve ecological regulation and management of pests.