异种化感物对落叶松八齿小蠹聚集行为的影响

Allelochemical Effects on Aggregation Behaviors of Ips subelongatus(Coleoptera: Scolytidae)

【目的】研究寄主、非寄主及近缘种的异种化感物对落叶松八齿小蠹聚集行为的影响,探讨不同信息素成分间的交互作用机制,为落叶松八齿小蠹大面积生物防治提供技术支持。【方法】从行为学的角度研究落叶松八齿小蠹对聚集信息素异构体、寄主挥发物、非寄主挥发物和近缘种云杉八齿小蠹主要聚集信息素成分的行为响应差异。【结果】通过野外试验确认落叶松八齿小蠹聚集信息素成分是S-（-）-小蠹烯醇和S-（＋）-小蠹二烯醇,这2种成分复合体在林间生物测试时表现出非常高的引诱活性;电生理测试确认落叶松八齿小蠹雌雄虫触角对这2种成分的检测阈值都是0.1μg,饱和水平是100μg。进一步对具有触角电位活性的寄主、非寄主及近缘种成分进行行为测试研究。寄主单萜烯成分S-β-蒎烯和3-蒈烯对落叶松八齿小蠹聚集信息素的引诱能力增效达1.45~1.65倍,而S-α-蒎烯和萜品油烯没有显著的增效作用。非寄主成分顺-3-己烯-1-醇表现出显著的行为抑制活性,能降低聚集信息素引诱力71%,里哪醇具有与顺-3-己烯-1-醇相似的抑制效果。其他非寄主成分如桃金娘烯醇、反-3-己烯-1-醇、反-2-己烯-1-醇、正己醇、3-辛醇和1-辛烯-3-醇对落叶松八齿小蠹聚集信息素引诱效果没有显著影响。近缘种云杉八齿小蠹主要聚集信息素成分顺式马鞭草烯醇能完全抑制落叶松八齿小蠹聚集信息素的引诱活性,反式马鞭草烯醇也具有相同的作用效果,而马鞭草烯酮成分对落叶松八齿小蠹聚集信息素活性没有抑制或增效作用。【结论】具有触角电位活性的寄主和非寄主成分对落叶松八齿小蠹聚集信息素行为活性表现出增效、抑制或无显著影响;对近缘种化学信号响应表现出强烈的行为抑制效果。

【Objective】The Asian larch bark beetle Ips subelongatus（Coleoptera： Scolytidae） is the main larch pest insect in northeastern China. Its continuous outbreaks in these regions pose a serious threat to the larch forests. In order to explore the mutual action mechanism of different allelochemicals from host,non-host,and sibling species as well as to provide a strong technical support in the biological control of I. subelongatus in large area,we investigated the effects of allelochemicals on aggregation behaviors of I. subelongatus. 【Method 】The behavioral bioassay methods were used to investigate the behavioral differences of I. subelongatus in responses to different enantiomers of its aggregation pheromone components,host volatiles,non-host volatiles,and pheromone components from sibling species.【Result】The aggregation pheromone components were determined to be S-（-）-ipsenol and S-（＋）-ipsdienol enantiomeric compositions in field trapping bioassays,which presented very high aggregation activity. Electroantennogram dose-responses studies indicated that antennal response threshold to S-（-）-ipsenol and S-（＋）-ipsdienol were all 0. 1 μg and the saturation level were100 μg. Furthermore, the behavioral effects of I. subelongatus to electroantennographic detection（EAD） active semiochemicals from hosts,non-hosts,and closely related bark beetle species were tested in the field trapping bioassays.The attraction of I. subelongatus to a synthetic pheromone source was significantly increased（1. 45- 1. 65 times） when the EAD-active monoterpenes,S-（-）-β-pinene or 3-carene was added to the source. But,addition of EAD-active components S-α-pinene or Terpinolene to trap with synthetic pheromone did not significantly increase trap catches. In field trapping experiments,the non-host volatile（Z）-3-hexen-1-ol reduced I. subelongatus trap catches by 71%,showing a strong inhibitory effects on the pheromone source. Linalool demonstrated the same inhibitory effects as（Z）-3-hexen-1-ol.The other non-host volatiles,for example,Myrtenol,（E）-3-hexen-1-ol,（E）-2-hexen-1-ol,1-hexanol,3-octanol,and 1-octen-3-ol had no synergistic or antagonistic effects on I. subelongatus attraction when added to the pheromone trap,whereas cis-verbenol（the major constituent of the aggregaton pheromone of Ips typographus） and trans-verbenol inhibited its attraction to the S-（-）-ipsenol and S-（＋）-ipsdienol-containing attractive blend. However,adding the verbenone to pheromone-baited traps did not reduce I. subelongatus attraction,which had an inhibitory effect on I. typographus pheormone baited traps.【Conclusion】EAD-active host and non-host volatiles either had synergized or antagonized,or no effect on I. subelongatus response to its aggregation pheromone; the strong inhibitory effects of semiochemicals from sibling species on I. subelongatus response to its aggregaton pheormone were observed. These results laid the foundation for the development of efficient lures and biological control of I. subelongatus in large area.