Zhang Qing-He, Ma Jian-Hai, Zhao Feng-Yu, Song Li-Wen, Sun Jiang-Hua
Sterling International, Inc., 3808 N. Sullivan Rd, Bldg 16p, Spokane, WA 99216-1630, USA.
J Chem Ecol. 2009 May;35(5):610-7. doi: 10.1007/s10886-009-9634-4. Epub 2009 May 1.
Volatiles from hindgut extracts of males of the Qinghai spruce bark beetle, Ips nitidus, from different attack phases (phase 1: unpaired males and phases 2-4: males joined with one to three females) and hindgut extracts of mated females were analyzed by gas chromatography-mass spectrometry (GC-MS)/flame ionization detection (FID) with both polar and enantioselective columns. The GC-MS/FID analyses demonstrated that unpaired males from attack phase 1 (nuptial chamber constructed) produced 2-methyl-3-buten-2-ol, approx. 74%-(-)-ipsdienol, and (-)-cis-verbenol as major hindgut components, and (-)-trans-verbenol, (-)-ipsenol, (-)-verbenone, myrtenol, and 2-phenylethanol as minor or trace components. The quantities of 2-methyl-3-buten-2-ol and especially ipsdienol decreased after mating during phases 2-4, whereas the quantities of (-)-cis- and (-)-trans-verbenol did not change. In contrast, the quantity of (-)-ipsenol seemed to increase as mating activity progressed. After mating with three females (harem size = 3; phase 4), only trace to small amounts of male-specific compounds were detected from I. nitidus male hindguts. Chemical analysis of the hindgut extracts of mated females showed only trace amounts of semiochemicals. A field-trapping bioassay in Qinghai, China showed that the four-component "full blend" containing the three major components, 2-methyl-3-buten-2-ol, (+/-)-ipsdienol, and (-)-cis-verbenol, plus a minor component, (-)-trans-verbenol, caught significantly more I. nitidus (male/female = 1:2.2) than did the unbaited control and two binary blends. The replacement of (+/-)-ipsdienol with nearly enantiomerically pure (-)-ipsdienol in the "full blend" significantly reduced trap catches, which suggests that both enantiomers are needed for attraction. On the other hand, removal of (-)-trans-verbenol from the active "full blend" had no significant effect on trap catches. Our results suggest that the three major components, 2-methyl-3-buten-2-ol, 74%-(-)-ipsdienol, and (-)-cis-verbenol (at 7:2:1), produced by unpaired fed males, are likely the aggregation pheromone components of I. nitidus, thus representing the first characterization of an aggregation pheromone system of a bark beetle native solely to China.
利用气相色谱 - 质谱联用仪（GC - MS）/火焰离子化检测器（FID），通过极性柱和对映体选择性柱，对青海云杉八齿小蠹（Ips nitidus）不同攻击阶段（阶段1：未配对雄虫；阶段2 - 4：与一至三只雌虫配对的雄虫）雄虫后肠提取物以及已交配雌虫的后肠提取物中的挥发性物质进行了分析。GC - MS/FID分析表明，处于攻击阶段1（已构建婚室）的未配对雄虫产生的主要后肠成分有2 - 甲基 - 3 - 丁烯 - 2 - 醇、约74%的（ - ）- Ipsdienol和（ - ）- 顺式马鞭草烯醇，次要或痕量成分有（ - ）- 反式马鞭草烯醇、（ - ）- Ipsenol、（ - ）- 马鞭草烯酮、桃金娘烯醇和2 - 苯乙醇。在阶段2 - 4交配后，2 - 甲基 - 3 - 丁烯 - 2 - 醇尤其是Ipsdienol的含量下降，而（ - ）- 顺式和（ - ）- 反式马鞭草烯醇的含量没有变化。相反，（ - ）- Ipsenol的含量似乎随着交配活动的进行而增加。在与三只雌虫交配后（后宫规模 = 3；阶段4），从青海云杉八齿小蠹雄虫后肠中仅检测到痕量至少量的雄性特异性化合物。已交配雌虫后肠提取物的化学分析仅显示出痕量的信息素。在中国青海进行的田间诱捕生物测定表明，包含三种主要成分2 - 甲基 - 3 - 丁烯 - 2 - 醇、（±）- Ipsdienol和（ - ）- 顺式马鞭草烯醇以及一种次要成分（ - ）- 反式马鞭草烯醇的四组分“全混合物”诱捕到的青海云杉八齿小蠹（雄/雌 = 1:2.2）显著多于未设诱饵的对照和两种二元混合物。在“全混合物”中用几乎对映体纯的（ - ）- Ipsdienol替代（±）- Ipsdienol会显著减少诱捕量，这表明两种对映体对于吸引都是必需的。另一方面，从活性“全混合物”中去除（ - ）- 反式马鞭草烯醇对诱捕量没有显著影响。我们的结果表明，未配对取食雄虫产生的三种主要成分2 - 甲基 - 3 - 丁烯 - 2 - 醇、74%的（ - ）- Ipsdienol和（ - ）- 顺式马鞭草烯醇（比例为7:2:1）可能是青海云杉八齿小蠹的聚集信息素成分，因此这是对仅原产于中国的一种树皮甲虫聚集信息素系统的首次表征。
