Arraztio Diego, Huerta Amanda, Quiroz Andrés, Aniñir Washington, Rebolledo Ramón, Curkovic Tomislav
Doctorado en Ciencias Silvoagropecuarias y Veterinarias, Facultad de Cs. Agronómicas, Universidad de Chile, Santiago P.O. Box 1004, Chile.
Facultad de Ciencias Forestales y de la Conservación de la Naturaleza, Universidad de Chile, Santiago P.O. Box 9206, Chile.
Insects. 2024 Sep 26;15(10):741. doi: 10.3390/insects15100741.
During the spring-summer seasons between 2019 and 2023, in the localities of Maquehue (La Araucanía Region) and Llifén (Los Ríos Region), we collected 262 virgin (1 female/2.3 males) specimens emerging from the live trunks of trees, an atypical sex ratio in Cerambycidae, suggesting high male competition for females. Virgin specimens of both sexes were individually placed in panel traps in the field, capturing only males (n = 184) over the field study seasons and only in traps baited with females. This fact preliminarily suggests the females emit possible "volatile or airborne" pheromones (eventually being a long-range sex pheromone), something unusual in Cerambycinae, the subfamily to which it currently belongs, although the taxonomic status of the species is under debate. In Llifén and Santiago (Metropolitan Region), behavioral observations were conducted, which allowed us to define the conditions necessary for male-female encounters that were replicated when carrying out volatile captures (Head Space Dynamic = HSD) and collections of compounds from terminalias excised from females. In field trials, virgin females less than ten days old were more attractive than older ones and attracted males during the night, i.e., between 23:00 and 5:00 AM, when the ambient temperature exceeded 11.6 °C. The aeration of females under the conditions described above and subsequent analysis of extracts by GC-MS allowed the identification of compounds absent in males and the control, including two oxygenated sesquiterpenes, a nitrogenous compound (C), and a long-chain hydrocarbon (C). From the terminalia extracts, hentriacontane, heptacosane, and heneicosyl, heptacosyl and docosyl acetates were identified by GC-MS, and their roles are unknown in the development of short-distance sexual behaviors, but they could serve to mark a trail leading the male towards the female in the final stage of approach for courtship/mating. Thus, we proposed the hypothesis that females emit both a long-range and a trail-pheromone, which, if confirmed, would be a rare case in this family. The specific identity of the compounds obtained by HSD, as well as the activities of these chemicals and those obtained from the terminalias, should be evaluated in future behavioral studies, as well as regarding their potential to attract males under field conditions. The current document is the first report on volatiles obtained from aerations and compounds extracted from female terminalia in .
在2019年至2023年的春夏季，我们在马奎韦（阿劳卡尼亚大区）和利芬（洛斯里奥斯大区）两地，从活树干中采集了262只未交配的标本（雌性与雄性比例为1:2.3），这在天牛科中是一个非典型的性别比例，表明雄性对雌性的竞争激烈。两性的未交配标本被单独放置在野外的平板诱捕器中，在整个野外研究季节，仅在以雌性为诱饵的诱捕器中捕获到了雄性（n = 184）。这一事实初步表明，雌性会释放可能的“挥发性或空气传播的”信息素（最终可能是一种远距离性信息素），这在它目前所属的天牛亚科中是不寻常的，尽管该物种的分类地位仍存在争议。在利芬和圣地亚哥（首都大区）进行了行为观察，这使我们能够确定雌雄相遇所需的条件，这些条件在进行挥发性捕获（顶空动态 = HSD）和从雌性切除的末端采集化合物时得到了重现。在野外试验中，不到十天大的未交配雌性比年龄较大的更具吸引力，并且在夜间（即23:00至凌晨5:00）吸引雄性，此时环境温度超过11.6°C。在上述条件下对雌性进行通气处理，随后通过气相色谱 - 质谱联用仪（GC - MS）对提取物进行分析，从而鉴定出雄性和对照中不存在的化合物，包括两种氧化倍半萜、一种含氮化合物（C）和一种长链烃（C）。通过GC - MS从末端提取物中鉴定出三十一烷、二十七烷以及二十一烷基、二十七烷基和二十二烷基乙酸酯，它们在近距离性行为发展中的作用尚不清楚，但它们可能在求偶/交配接近的最后阶段用于标记引导雄性走向雌性的踪迹。因此，我们提出了一个假设，即雌性会释放一种远距离信息素和一种踪迹信息素，如果这一假设得到证实，在这个科中将是一个罕见的案例。通过HSD获得的化合物的具体身份，以及这些化学物质和从末端获得的化学物质的活性，应在未来的行为研究中进行评估，以及它们在野外条件下吸引雄性的潜力。本文件是关于从通气处理中获得的挥发性物质以及从雌性末端提取的化合物的第一份报告。
