Evidence for a Sex Pheromone in Bark Beetle Parasitoid Roptrocerus xylophagorum
Evidence for a Sex Pheromone in Bark Beetle Parasitoid Roptrocerus xylophagorum
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树皮甲虫寄生蜂 Roptrocerus xylophagorum 中性信息素的证据
DOI：
10.1023/a:1015270003717
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发表时间：
2002
影响因子：
2.3
通讯作者：
B. Sullivan
中科院分区：
文献类型：
--
作者：
B. Sullivan
当雄性Roptrocerus xylophagorum（Ratzeburg）（膜翅目：翼龙科）暴露于涂有雌性全身提取物的己烷、丙酮或甲醇溶液的玻璃球诱饵时，表现出求偶和交配行为，包括扇动翅膀、触角、骑乘和尝试交配。经过提取物处理的诱饵的活性在一周内逐渐下降。与未提取的尸体相比，雄性对用溶剂提取的冷冻杀死的女性尸体的反应要弱得多；用女性提取物处理提取的尸体可以恢复男性的反应。研究发现，该信息素同样存在于雌性腹部和头部/胸部的表面，并且该信息素的来源不能最终定位于任何单一身体区域。雌性的信息素活性在羽化后第 1 天和第 3-5 天之间增加；除此之外，信息素活性并未受到雌性年龄或交配的显着影响。雄性被捕获在雌性曾走过的玻璃表面区域内，这表明信息素可能是底物传播的。最近与雌性的接触降低了雄性的反应性，但在雄性与雌性隔离几个小时后，反应性完全恢复。当整个雌性的己烷提取物在硅胶上进行分级时，信息素的活性在第一个、最非极性的部分中大部分恢复。通过气相色谱-质谱联用分析女性提取物和级分。角质层烃烷被确定为提取物成分，其浓度与男性反应最相关。信息素的长期持久性、低挥发性、低极性以及存在于昆虫整个身体表面的证据进一步支持了信息素由一种或多种表皮碳氢化合物组成的假设。
MaleRoptrocerus xylophagorum(Ratzeburg) (Hymenoptera: Pteromalidae) exhibited courtship and mating behaviors including wing fanning, antennation, mounting, and copulation attempts when exposed to glass bulb decoys coated with a whole-body extract of females in hexane, acetone, or methanol. Activity of extract-treated decoys declined gradually over one week. Males responded much less strongly to freeze-killed female cadavers extracted with solvents than to unextracted cadavers; treatment of extracted cadavers with female extract restored male responses. The pheromone was found to be equally present over the surface of both the abdomen and head/thorax of females, and the origin of the pheromone could not be conclusively localized to any single body region. The activity of pheromone on females increased between day 1 and days 3–5 following eclosion; otherwise, pheromone activity was not significantly affected by either female age or mating. Males were arrested within the zone of a glass surface on which females had walked, suggesting that the pheromone might be substrate-borne. Recent exposure to females reduced male responsiveness, but responsiveness was fully restored after a few hours of male isolation from females. When hexane extracts of whole females were fractionated on silica gel, the pheromone's activity was largely recovered with the first, most nonpolar fraction. Female extracts and fractions were analyzed by coupled gas chromatography–mass spectrometry. Cuticular hydrocarbon alkanes were identified as the extract components whose concentrations correlated best with male responses. Evidence of the pheromone's long persistence, low volatility, low polarity, and presence over the insect's entire body surface further supported the hypothesis that the pheromone was composed of one or more cuticular hydrocarbons.