Trypodendron retusum (LeConte) (Coleoptera: Curculionidae: Scolytinae) females excised from newly attacked trembling aspen, Populus tremuloides Michaux (Salicaceae), were shown for the first time to produce the aggregation pheromone (+)-lineatin. Coupled gas chromatographic-electroantennographic detection analysis (GC-EAD) disclosed that the antennae of T. retusum, as well as the antennae of three sympatric species, native T. lineatum (Olivier) and T. rufitarsus (Kirby) and exotic T. domesticum (L.), respond to synthetic (+)-lineatin, but not the (-) enantiomer. In contrast, the antennae of T. betulae Swaine responded to SR- and RR-linalool oxide pyranoid and did not detect lineatin. GC-EAD analysis of volatiles from host and nonhost tree species revealed that conifer-produced α-pinene and angiosperm-produced conophthorin and salicylaldehyde were perceived by the antennae of all three native lineatin-perceiving species, suggesting behavioral activity. Field trapping experiments showed that salicylaldehyde synergized the response of coastal, but not interior, T. retusum to lineatin and inhibited the response of T. lineatum and T. rufitarsus. In the absence of salicylaldehyde, α-pinene appeared to inhibit the response of interior T. retusum to lineatin, while for T. lineatum and T. rufitarsus it had an apparent positive additive or synergistic effect. No behavioral response occurred to conophthorin. The results provide evidence for semiochemical-based reproductive isolation between T. retusum and T. betulae, and between these two angiosperm-infesting species and the two conifer-infesting species. They do not explain how isolation could be maintained between T. lineatum and T. rufitarsus.

中文翻译：

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基于信息化学的锥虫同域物种的生殖隔离（鞘翅目：Curculionidae：Scolytinae）

Trypodendron retusum (LeConte) (Coleoptera: Curculionidae: Scolytinae) 雌性从新攻击的颤抖白杨、Populus tremuloides Michaux (Salicaceae) 中切除，首次显示出产生聚集信息素 (+)-lineatin。气相色谱-触角电图检测分析 (GC-EAD) 揭示了 T. retusum 的触角，以及三种同域物种的触角，即本地 T. lineatum (Olivier) 和 T. rufitarsus (Kirby) 以及外来 T. domesticum (L.)，对合成的 (+)-lineatin 有反应，但对 (-) 对映异构体没有反应。相反，T. betulae Swaine 的触角对 SR-和 RR-芳樟醇氧化物吡喃有反应，但没有检测到 lineatin。对寄主和非寄主树种挥发物的 GC-EAD 分析表明，针叶树产生的 α-蒎烯和被子植物产生的茄碱和水杨醛都被所有三种原生 lineatin 感知物种的触角感知，表明行为活动。田间诱捕实验表明，水杨醛协同了沿海而不是内部的 T. retusum 对 lineatin 的反应，并抑制了 T. lineatum 和 T. rufitarsus 的反应。在没有水杨醛的情况下，α-蒎烯似乎抑制了内部 T. retusum 对 lineatin 的反应，而对于 T. lineatum 和 T. rufitarsus，它具有明显的正相加或协同作用。对茄素没有发生行为反应。该结果为 T. retusum 和 T. betulae 之间基于信息化学的生殖隔离提供了证据，在这两种侵染被子植物的物种和两种侵染针叶植物的物种之间。他们没有解释如何在 T. lineatum 和 T. rufitarsus 之间保持隔离。