Palmer Christine M, Wershoven Nicole L, Martinson Sharon J, Ter Hofstede Hannah M, Kress W John, Symes Laurel B
Natural Sciences Department, Castleton University, 233 South Street, Castleton, VT 05735, USA.
Department of Biological Sciences, Dartmouth College, 78 College Street, Hanover, NH 03755, USA.
Diversity (Basel). 2022 Feb;14(2). doi: 10.3390/d14020152. Epub 2022 Feb 21.
Many well-studied animal species use conspicuous, repetitive signals that attract both mates and predators. Orthopterans (crickets, katydids, and grasshoppers) are renowned for their acoustic signals. In Neotropical forests, however, many katydid species produce extremely short signals, totaling only a few seconds of sound per night, likely in response to predation by acoustically orienting predators. The rare signals of these katydid species raises the question of how they find conspecific mates in a structurally complex rainforest. While acoustic mechanisms, such as duetting, likely facilitate mate finding, we test the hypothesis that mate finding is further facilitated by colocalization on particular host plant species. DNA barcoding allows us to identify recently consumed plants from katydid stomach contents. We use DNA barcoding to test the prediction that katydids of the same species will have closely related plant species in their stomach. We do not find evidence for dietary specialization. Instead, katydids consumed a wide mix of plants within and across the flowering plants (27 species in 22 genera, 16 families, and 12 orders) with particular representation in the orders Fabales and Laurales. Some evidence indicates that katydids may gather on plants during a narrow window of rapid leaf out, but additional investigations are required to determine whether katydid mate finding is facilitated by gathering at transient food resources.
许多经过充分研究的动物物种会使用显眼的、重复性的信号，这些信号既能吸引配偶，也会引来捕食者。直翅目昆虫（蟋蟀、螽斯和蚱蜢）以其声学信号而闻名。然而，在新热带森林中，许多螽斯物种发出的信号极其短暂，每晚发出的声音总共只有几秒，这可能是为了应对通过声音定位捕食的捕食者。这些螽斯物种发出的罕见信号引发了一个问题：它们如何在结构复杂的雨林中找到同种配偶。虽然诸如二重唱等声学机制可能有助于寻找配偶，但我们检验了这样一种假设，即通过在特定寄主植物物种上共定位能进一步促进配偶的寻找。DNA条形码技术使我们能够从螽斯的胃内容物中识别出它们最近食用过的植物。我们使用DNA条形码技术来检验这样的预测：同一物种的螽斯胃中的植物物种会密切相关。我们没有找到饮食特化的证据。相反，螽斯食用了开花植物内部和不同开花植物之间的多种植物（22个属、16个科和12个目中的27个物种），其中豆目和樟目有特别的代表性。一些证据表明，螽斯可能会在叶片快速长出的狭窄窗口期聚集在植物上，但还需要进一步的研究来确定螽斯通过聚集在短暂的食物资源处是否有助于找到配偶。
