【作者】 宋丽文；

【导师】 任炳忠； 高长启；

【作者基本信息】 东北师范大学 ， 动物学， 2010， 博士

【摘要】 小蠹虫是林木害虫的一个重要类群,暴发时可造成严重的经济和生态损失。先锋性的小蠹虫可直接侵害健康树,对森林构成直接威胁；而次期性小蠹虽然主要侵害衰弱木,但当种群密度达到猖獗发生的水平时同样可直接危害健康木。本论文主要以两种针叶树小蠹为研究对象,一种为攻击性较强的的落叶松八齿小蠹(Ips subelongatus Motsch) (Coleoptera:Curculionidae:Scolytinae),作为北方落叶松林蛀干害虫的先锋种,落叶松八齿小蠹经常猖獗成灾,侵害健康或半健康活立木,对落叶松人工林经营构成了巨大威胁；另一种是次期性害虫柏肤小蠹(Phloeosinus aubei Perris) (Coleoptera:Curculionidae:Scolytinae),可危害柏木属(Cupressus)和刺柏属(Juniperus)的一些树种,在我国主要寄主为侧柏(Platycladus orientalis(L.)Franco)和桧柏(Juniperus chinensis L.),一般侵害长势衰弱或新移植后生长势未恢复的柏树,是柏树的一种毁灭性害虫。小蠹虫具有复杂的化学信息系统,植物挥发性气味在寄主选择中起主导作用的同时,小蠹虫又产生聚集信息素以召集同种个体共同危害,而且,非寄主植物挥发物在小蠹虫的寄主选择中发挥重要作用。本文在提取分析信息素、寄主与非寄主植物挥发物的基础上,通过室内及田间实验分别系统研究了聚集信息素、寄主植物挥发物及非寄主植物挥发物对两种针叶树小蠹聚集行为的影响,进而探讨它们不同的寄主选择机制。落叶松八齿小蠹成虫可以在聚集信息素的作用下产生大量的聚集行为,但野外行为生测研究发现内蒙古自治区和吉林省的两个落叶松八齿小蠹种群对聚集信息素的反应有很强的地理差异。这两个地理种群对潜在聚集信息素成分小蠹烯醇(ipsenol)[消旋或(-)-异构体]、小蠹二烯醇(ipsdienol)[消旋或(+)-异构体]及3-甲基-3-丁烯-1-醇(3-methyl-3-buten-1-ol)的行为反应实验表明,在内蒙古[华北落叶松(Larix principis-rupprechtii Mayr.)人工林],小蠹烯醇[消旋或97%-(-)-]是唯一对落叶松八齿小蠢有引诱活性的信息素成分；而在吉林省[兴安落叶松(L. gmelini (Rupr.) Rupr.)人工林],小蠹烯醇和小蠹二烯醇是两种主要的信息素成分,且具有强烈的交互作用,任何一种成分兽独使用都没有引诱活性。野外观察发现落叶松饵木可以大量诱集落叶松八齿小蠹,气相色谱-质谱(GC-MS)分析结果表明,落叶松挥发物以a-pinene、β-pinene、β-phellandrene等单蒈烯类成分为主,虽然在触角电位(EAG)测试中落叶松八齿小蠹成虫对a-pinene等寄主挥发物有一定的电生理反应,但田间实验未发现该虫对寄主原物质或寄主挥发物的单蒈类混合物有显著行为趋性。在非寄主(或非适宜寄主)植物挥发物对落叶松八齿小蠹的驱避行为实验中,以聚集信息素的诱集量为正对照,trans-conophthorin +verbenone、1-hexanol+trans-conophthorin +verbene、1-hexanol+ trans-conophthorin+ geranylacetone+ verbenone的组合处理对落叶松八齿小蠹有强烈的驱避作用,完全抵销了聚集信息素的引诱作用。在单组分的非寄主挥发物中,verbenone对落叶松八齿小蠹的驱避活性最强,其次geranylacetone、trans-conophthorin单组分也有一定的驱避作用。说明落叶松八齿小蠹可以在生境、种类及个体多个水平上识别非寄主植物或非适宜寄主,通过避开非寄主或非适宜寄主个体以尽快定位适宜的寄主。柏肤小蠹后肠产物分析及行为生测未发现该虫产生聚集信息素的迹象,但柏肤小蠹成虫对侧柏饵木有强烈的趋性。GC-MS分析到侧柏挥发物中大约15种成分,以a-pinene、△-3-carene、sabinene、widdrene等为主。通过气相色谱-触角电位联用(GC-EAD)测试主要发现柏肤小蠹对a-pinene、a-felendre、△-3-carene、a-terpene、DL-limonene等5种侧柏单萜类挥发物的电生理反应,野外行为生测中,turpentine + ethanol和Hostowit两种组合处理对柏肤小蠹有显著的行为引诱活性,而与其同域分布的另一种同样寄生于侧柏的微肤小蠹对高释放速率的(95%-)-a-pinene产生强烈的趋性反应。此外,我们还对落叶松八齿小蠹和柏肤小蠹进行了触角扫描电镜观察,这两种小蠹成虫触角均呈膝状,分为柄节、梗节、鞭节3部分,触角上的感器种类、分布与已知鳞翅目、膜翅目中昆虫触角的感器种类和分布有很大的差别。初步确定柏肤小蠹触角上存在5种类型的感受器,包括毛型感受器、栉型感受器、锯齿型感受器、刺型感受器、腔型感受器；落叶松八齿小蠹触角上主要发现4种感受器：锯齿状感器、毛型感器、腔型感器、芽型感器。未发现雌雄成虫触角感器类型有显著差别。更多还原

【Abstract】 Bark beetles are a group of the most important forest insect pests which cause significant economic and ecological losses when the population reaches epidemic level. The pioneer bark beetles can kill the healthy trees as the direct threats to the forest. Although the secondary bark beetles mainly attack weaken or dying trees, they can also attack healthy trees at high population densities.The objects of the dissertation mainly focus on two conifer bark beetles, one is the Asian larch bark beetle, Ips subelongatus Motsch (Coleoptera:Curculionidae:Scolytinae), which is more aggressive species. As one of the pioneer insect pests in larch plantation, the Asian larch bark beetle often outbreaks and attacks healthy larch trees thereby causing significant tree mortality in this region; The other object is a secondary beetle, Phloeosinus aubei Perris (Coleoptera:Curculionidae:Scolytinae), which may infest Cupressus and Juniperus species. Its major host in China is Oriental Arborvitae, Platycladus orientalis (L.) Franco and Chinese Juniper, Juniperus chinensis L. As a destructive insect pest of juniper, it usually attacks weaken or newly planted trees.Bark beetles have complicated semiochemical communication system. With the plant volatiles as dominants for host selection, bark beetles also produce aggregation pheromones to call conspecies to have mass attack. Meanwhile, non-host volatiles (NHV) play an important role for host selection as well. In this dissertation, on the basis of extraction and analysis on pheromones, host volatiles (HV) and NHV, the efficacy of pheromones, HVs and NHVs on the two bark beetles were studied for manipulating their aggregation behavior by the methods of the electro-physiological or field test. And their host selection mechanism were furtherly discussed. The adult Asian larch bark beetles may aggregate in large amounts with aggregation pheromones. However, the field bioassay results in two provinces (Inner Mongolia and Jilin) of northeastern China suggest that there is a strong geographical variation in aggregation pheromone response of I. subelongatus in northeastern China. Behavioral responses of I. subelongatus Motsch. to three potential aggregation pheromone components, ipsenol [racemic or (-)-enantiomer], ipsdienol [racemic or (+)-enantiomer] and 3-methyl-3-buten-l-ol, were tested in Inner Mongolia and Jilin Province. Our field bioassays in Inner Mongolia (Larix principis-rupprechtii Mayr. plantation) clearly showed that ipsenol, either racemic or 97%-(-)-enantiomer, was the only compound that significantly attracted both sexes of I. subelongatus, while all other compounds (singly or in combinations) were unattractive. There were no two or three-way synergistic interactions. In Jilin Province [L. gmelini (Rupr.) Rupr. plantation], however, all the individual compounds tested were inactive, while a combination of ipsenol and ipsdienol [racemates or enantiomerically pure natural enantiomers] showed a significant attraction to both sexes of I. subelongatus, indicating a two-way synergistic interaction between these two major components. Addition of 3-methyl-3-buten-l-ol to these active binary blend(s) did not have any effects on trap catches, suggesting that ipsenol and ipsdienol are the synergistic aggregation pheromone components of I.subelongatus in Jilin province.Both sexes of adult I. subelongatus are strongly attracted by Larix logs. Analysis on aeration of larch logs by Gas Chromatography-Mass Spectrometry (GC-MS) showed that the major volatiles of larch logs were monoterpenes such as a-pinene,β-pinene andβ-phellandrene. Although bioassay with Electro-Antenna-Graphy Recording (EAG) detected the electrophysiological response of I. subelongatus to a-pinene, no behavioral responses were observed in the field bioassay for attraction of I. subelongatus to the host materials or host monoterpene mixture.In the field bioassay of I. subelongatus to non-host volatiles (NHV) with aggregation pheromones as positive control, the combinations of trans-conophthorin +verbenone, 1-hexanol+ trans-conophthorin +verbenone and 1-hexanol+ trans-conophthorin+ geranylacetone+ verbenone showed strong repellent to both sexes of I. subelongatus. As to the single component NHV, verbenone has the strongest repellent bioactivity to I. subelongatus, then geranylacetone and trans-conophthorin were also active repellent. The results suggest that I. subelongatus may select the suitable host trees by rejecting non-host trees.As to Phloeosinus aubei, both analysis on hindguts extraction and behavorial test didn’t indicate any signals of aggregation pheromone production by the beetles. However, both sexes of adult P. aubei showed strong attractive response to cypress logs. Volatiles of Platycladus orientalis logs aeration analyzed by GC-MS mainly detected 15 chemicals with a-pinene,△-3-carene, sabinene, widdrene as the major components. GC—EAD detected the electrophysiological responses of P. aubei to the host monoterpene including a-pinene, a-felendre, A-3-carene, a-terpene, DL-limonene. In the field bioassay, the two treatments of turpentine+ethanol and Hostowit showed significant attraction to P. aubei. Whereas another sympatric bark beetle, P. hopehi, was strongly attracted by (95%-)-alpha-pinene.Meanwhile, antenna of I. Subelongatus and P. aubei were observed by scanning electron microscope (SEM). It showed that antenna of the two species of beetles both present the shape of geniculation and was separated as three parts of scape, pedicel and flagellum. The type and distribution of the sensilla of the two beetles were greatly different from that of the known Coleoptera and Hymenoptera. Five types of sensilla were observed on P. aubei antenna which includes sensilla trichoid, sensilla ctenoid, sensilla hackle, sensilla chaetica, sensilla cavity. The main sensilla on I. Subelongatus observed were sensilla hackle, sensilla trichoid, sensilla cavity and sensilla gemmiformium. There was no obvious difference on structure and morphology between the male and female antenna.更多还原