Department of Biological Cybernetics, Faculty of Biology, Bielefeld University, 33615, Bielefeld, Germany.
Center for Cognitive Interaction Technology, Bielefeld University, 33615, Bielefeld, Germany.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2023 Mar;209(2):265-284. doi: 10.1007/s00359-022-01564-z. Epub 2022 Aug 20.
Overall body proportions and relative limb length are highly characteristic for most insect taxa. In case of the legs, limb length has mostly been discussed with regard to parameters of locomotor performance and, in particular cases, as an adaptation to environmental factors or to the mating system. Here, we compare three species of stick and leaf insects (Phasmatodea) that differ strongly in the length ratio between antennae and walking legs, with the antennae of Medauroidea extradentata being much shorter than its legs, nearly equal length of antennae and legs in Carausius morosus, and considerably longer antennae than front legs in Aretaon asperrimus. We show that that relative limb length is directly related to the near-range exploration effort, with complementary function of the antennae and front legs irrespective of their length ratio. Assuming that these inter-species differences hold for both sexes and all developmental stages, we further explore how relative limb length differs between sexes and how it changes throughout postembryonic development. We show that the pattern of limb-to-body proportions is species-characteristic despite sexual dimorphism, and find that the change in sexual dimorphism is strongest during the last two moults. Finally, we show that antennal growth rate is consistently higher than that of front legs, but differs categorically between the species investigated. Whereas antennal growth rate is constant in Carausius, the antennae grow exponentially in Medauroidea and with a sudden boost during the last moult in Aretaon.
总体身体比例和相对肢体长度对大多数昆虫类群来说具有高度特征性。就腿部而言，肢体长度主要与运动性能参数有关，在特殊情况下，作为对环境因素或交配系统的适应。在这里，我们比较了三种竹节虫（Phasmatodea），它们在触角和步行腿之间的长度比上差异很大，Medauroidea extradentata 的触角比腿短得多，Carausius morosus 的触角和腿几乎等长，而 Aretaon asperrimus 的触角比前腿长得多。我们表明，相对肢体长度与近距离探索努力直接相关，触角和前腿具有互补功能，而与它们的长度比无关。假设这些种间差异在两性和所有发育阶段都存在，我们进一步探讨了相对肢体长度在两性之间的差异以及它在胚胎后发育过程中的变化。我们表明，尽管存在性别二态性，但肢体与身体比例的模式具有物种特征性，并且发现性别二态性的变化在最后两次蜕皮期间最强。最后，我们表明，触角的生长速度始终高于前腿，但在研究的物种之间存在明显差异。在前腿中，触角的生长速度在 Carausius 中是恒定的，在 Medauroidea 中呈指数增长，而在 Aretaon 中最后一次蜕皮时突然增加。
