Favaris Arodí P, Túler Amanda C, Silva Weliton D, Pec Marvin, Rodrigues Sérgio R, Maia Artur C D, Bento José Maurício S
Department of Entomology and Acarology, University of São Paulo, Piracicaba, São Paulo, Brazil.
Mato Grosso Do Sul State University, Cassilândia, Mato Grosso Do Sul, Brazil.
Naturwissenschaften. 2023 Jan 26;110(1):3. doi: 10.1007/s00114-023-01831-2.
Cyclocephaline beetles are flower visitors attracted primarily by major floral volatiles. Addressing the identity of these volatile compounds is pivotal for understanding the evolution of plant-beetle interactions. We report the identification and field testing of the attractant volatiles from trumpet flowers, Brugmansia suaveolens (Willd.) Sweet (Solanaceae), for the beetle Cyclocephala paraguayensis Arrow (Melolonthidae: Dynastinae). Analysis of headspace floral volatiles revealed 19 compounds, from which eucalyptol (57%), methyl benzoate (16%), and β-myrcene (6%) were present in the largest amounts, whereas E-nerolidol in much lesser amounts (1.8%). During a first-field assay, traps baited with Mebe alone or blended with the other two major compounds attracted more beetles than myrcene and eucalyptol alone, which did not differ from the negative controls. In a second assay, Mebe and nerolidol attracted more beetles as a blend than individually. Nerolidol was more attractive than Mebe, and all treatments attracted more beetles than negative controls. The number of attracted beetles in the Mebe-nerolidol blend was greater than the combined sum of beetles attracted to these compounds alone, suggesting a synergistic interaction. The attraction of C. paraguayensis by trumpet-flower volatiles supports the beetle's extended preference for sphingophilous plants, especially when cantharophilous (beetle-pollinated) flowers are lacking. This phenomenon, thus, might have contributed to the widespread occurrence of this beetle throughout the Brazilian biomes.
金龟子科甲虫是主要被主要花卉挥发物吸引的访花者。确定这些挥发性化合物的身份对于理解植物与甲虫相互作用的进化至关重要。我们报告了对来自喇叭花（Brugmansia suaveolens (Willd.) Sweet，茄科）的吸引性挥发物进行的鉴定和田间测试，该挥发物针对巴拉圭金龟子（Cyclocephala paraguayensis Arrow，鳃金龟科：犀金龟亚科）。对顶空花卉挥发物的分析揭示了19种化合物，其中桉叶油素（57%）、苯甲酸甲酯（16%）和β-月桂烯（6%）含量最高，而反式橙花叔醇含量较少（1.8%）。在首次田间试验中，单独用苯甲酸甲酯或与其他两种主要化合物混合诱捕的陷阱比单独用月桂烯和桉叶油素诱捕到更多的甲虫，后两者与阴性对照没有差异。在第二次试验中，苯甲酸甲酯和橙花叔醇混合诱捕比单独诱捕吸引到更多的甲虫。橙花叔醇比苯甲酸甲酯更具吸引力，所有处理都比阴性对照吸引到更多的甲虫。苯甲酸甲酯 - 橙花叔醇混合物吸引的甲虫数量大于单独被这些化合物吸引的甲虫数量之和，表明存在协同相互作用。喇叭花挥发物对巴拉圭金龟子的吸引支持了该甲虫对喜天蛾科植物的广泛偏好，特别是在缺乏喜甲虫科（甲虫授粉）花朵的情况下。因此，这种现象可能促成了这种甲虫在巴西各生物群落中的广泛分布。
