Institut de Recherche sur la Biologie de l'Insecte, UMR 6035 CNRS-Université François Rabelais, Av Monge, Parc Grandmont, 37200 Tours, France.
J Insect Physiol. 2011 Jul;57(7):865-71. doi: 10.1016/j.jinsphys.2011.03.020. Epub 2011 Apr 1.
The wind-sensitive cercal system of Orthopteroid insects that mediates the detection of the approach of a predator is a very sensitive sensory system. It has been intensively analysed from a behavioural and neurobiological point of view, and constitutes a classical model system in neuroethology. The escape behaviour is triggered in orthopteroids by the detection of air-currents produced by approaching objects, allowing these insects to keep away from potential dangers. Nevertheless, escape behaviour has not been studied in terms of success. Moreover, an attacking predator is more than "air movement", it is also a visible moving entity. The sensory basis of predator detection is thus probably more complex than the perception of air movement by the cerci. We have used a piston mimicking an attacking running predator for a quantitative evaluation of the escape behaviour of wood crickets Nemobius sylvestris. The movement of the piston not only generates air movement, but it can be seen by the insect and can touch it as a natural predator. This procedure allowed us to study the escape behaviour in terms of detection and also in terms of success. Our results showed that 5-52% of crickets that detected the piston thrust were indeed touched. Crickets escaped to stimulation from behind better than to a stimulation from the front, even though they detected the approaching object similarly in both cases. After cerci ablation, 48% crickets were still able to detect a piston approaching from behind (compared with 79% of detection in intact insects) and 24% crickets escaped successfully (compared with 62% in the case of intact insects). So, cerci play a major role in the detection of an approaching object but other mechanoreceptors or sensory modalities are implicated in this detection. It is not possible to assure that other sensory modalities participate (in the case of intact animals) in the behaviour; rather, than in the absence of cerci other sensory modalities can partially mediate the behaviour. Nevertheless, neither antennae nor eyes seem to be used for detecting approaching objects, as their inactivation did not reduce their detection and escape abilities in the presence of cerci.
直翅目昆虫的风敏感尾须系统介导了对捕食者接近的检测，这是一种非常敏感的感觉系统。它已经从行为和神经生物学的角度进行了深入分析，是神经行为学的经典模式系统。直翅目昆虫通过检测接近物体产生的气流来触发逃避行为，从而使这些昆虫远离潜在的危险。然而，逃避行为并没有从成功的角度进行研究。此外，攻击型捕食者不仅仅是“空气运动”，它也是一个可见的移动实体。因此，捕食者的检测感觉基础可能比尾须对气流的感知更为复杂。我们使用一个模拟攻击型奔跑捕食者的活塞来对森林蟋蟀（Nemobius sylvestris）的逃避行为进行定量评估。活塞的运动不仅产生气流，而且昆虫可以看到它并可以像自然捕食者一样触摸它。这一程序使我们能够从检测和成功的角度研究逃避行为。我们的研究结果表明，5-52%检测到活塞推力的蟋蟀确实被触碰到了。蟋蟀从后面受到刺激时比从前面受到刺激时更容易逃跑，尽管它们在两种情况下对接近物体的检测相似。在切除尾须后，48%的蟋蟀仍然能够检测到从后面接近的活塞（与完整昆虫中 79%的检测相比），并且 24%的蟋蟀成功逃脱（与完整昆虫的 62%相比）。因此，尾须在检测接近物体方面起着重要作用，但其他机械感受器或感觉方式也参与了这种检测。不能保证其他感觉方式（在完整动物的情况下）参与了行为；而不是在没有尾须的情况下，其他感觉方式可以部分介导行为。然而，触角和眼睛似乎都没有用于检测接近的物体，因为它们的失活并没有降低它们在有尾须的情况下的检测和逃避能力。
