Department of Plant Protection Biology, Swedish University of Agricultural Sciences, PO Box 102, 230 53, Alnarp, Sweden.
J Chem Ecol. 2010 Jul;36(7):768-77. doi: 10.1007/s10886-010-9814-2. Epub 2010 Jun 15.
Adults of the sorghum chafer, Pachnoda interrupta Olivier (Coleoptera: Scarabaeidae: Cetoniinae), form aggregations during the mating period in July, but also in October. The beetles aggregate on food sources, e.g., Acacia spp. trees or sorghum with ripe seeds, to feed and mate. During the mating season, field trapping experiments with live beetles as bait demonstrated attraction of males to unmated females, but not to mated females or males, indicating the presence of a female-emitted sex pheromone. Unmated females combined with banana (food source) attracted significantly more males and females than did unmated females alone. Other combinations of beetles with banana were not more attractive than banana alone. Thus, aggregation behavior appears to be guided by a combination of pheromone and host volatiles. Females and males were extracted with hexane during the mating period, and the extracts were compared by using GC-MS. In a field trapping experiment, 19 compounds found only in females were tested, both singly and in a mixture. Traps baited with one of the female-associated compounds, phenylacetaldehyde, caught significantly more beetles than any other treatment. However, the sex ratio of beetles caught in these traps did not differ from that of control traps, and it is possible that other components may be involved in the sex pheromone signal. Furthermore, traps baited with a mixture of all 19 compounds attracted significantly fewer beetles than did phenylacetaldehyde alone.
高粱犀金龟成虫（鞘翅目：金龟科：犀金龟亚科）在 7 月的交配期形成聚集，但也在 10 月形成聚集。这些甲虫聚集在食物源上，例如金合欢树或有成熟种子的高粱，以觅食和交配。在交配季节，用活甲虫作为诱饵的野外诱捕实验表明，雄性对未交配的雌性有吸引力，但对已交配的雌性或雄性没有吸引力，表明存在雌性释放的性信息素。与香蕉（食物源）结合的未交配雌性比单独的未交配雌性吸引了更多的雄性和雌性。其他与香蕉结合的甲虫组合并不比单独的香蕉更具吸引力。因此，聚集行为似乎是由信息素和寄主挥发物共同引导的。在交配期间，用己烷提取雌性和雄性，并用 GC-MS 进行比较。在野外诱捕实验中，测试了在交配期间仅在雌性中发现的 19 种化合物，单独测试和混合测试。用一种与雌性相关的化合物苯乙醛作为诱饵的诱捕器捕获的甲虫明显多于任何其他处理。然而，这些诱捕器捕获的甲虫的性别比例与对照诱捕器没有差异，可能还有其他成分参与性信息素信号。此外，用 19 种化合物的混合物作为诱饵的诱捕器吸引的甲虫明显少于单独用苯乙醛作为诱饵的诱捕器。
