Gibson Jeremy S, Cocroft Reginald B
Division of Biological Sciences, University of Missouri, Columbia, MO 65211, USA
Division of Biological Sciences, University of Missouri, Columbia, MO 65211, USA.
J Exp Biol. 2018 Mar 22;221(Pt 6):jeb175083. doi: 10.1242/jeb.175083.
Animal movement decisions involve an action-perception cycle in which sensory flow influences motor output. Key aspects of the action-perception cycle involved in movement decisions can be identified by integrating path information with measurement of environmental cues. We studied mate searching in insects for which the primary sensory cues are mechanical vibrations traveling through the tissues of living plants. We mapped search paths of male thornbug treehoppers locating stationary females through an exchange of vibrational signals. At each of the males' sampling locations, we used two-dimensional laser vibrometry to measure stem motion produced by female vibrational signals. We related properties of the vibrational signals to the males' movement direction, inter-sample distance and accuracy. Males experienced gradients in signal amplitude and in the whirling motion of the plant stem, and these gradients were influenced to varying degrees by source distance and local stem properties. Males changed their sampling behavior during the search, making longer inter-sample movements farther from the source, where uncertainty is higher. The primary directional cue used by searching males was the direction of wave propagation, and males made more accurate decisions when signal amplitude was higher, when time delays were longer between the front and back legs, and when female responses were short in duration. The whirling motion of plant stems, including both the eccentricity and the major axes of motion, is a fundamental feature of vibrational environments on living plants, and we show for the first time that it has important influences on the decisions of vibrationally homing insects.
动物的运动决策涉及一个动作-感知循环，其中感觉信息流会影响运动输出。通过将路径信息与环境线索的测量相结合，可以确定运动决策中动作-感知循环的关键方面。我们研究了昆虫的配偶搜索行为，其主要感觉线索是通过活植物组织传播的机械振动。我们绘制了雄性棘背叶蝉通过振动信号交换定位静止雌性的搜索路径。在每个雄性的采样位置，我们使用二维激光振动测量法来测量由雌性振动信号产生的茎干运动。我们将振动信号的特性与雄性的运动方向、样本间距离和准确性联系起来。雄性在信号幅度和植物茎干的旋转运动方面经历了梯度变化，这些梯度在不同程度上受到源距离和局部茎干特性的影响。雄性在搜索过程中改变了它们的采样行为，在离源更远、不确定性更高的地方进行更长的样本间移动。搜索中的雄性使用的主要方向线索是波传播的方向，当信号幅度更高、前后腿之间的时间延迟更长以及雌性反应持续时间较短时，雄性会做出更准确的决策。植物茎干的旋转运动，包括运动的偏心率和主轴，是活植物振动环境的一个基本特征，我们首次表明它对振动归巢昆虫的决策有重要影响。
