Deceptive signals in spiders

Spiders are well known as prolific and efficient predators that overwhelm their prey with potent toxins or strong silks. The deployment of cunning tactics to lure and deceive their prey is less appreciated despite a considerable history of research into deceptive spider signals. In the early twentieth century, observations already suggested the presence of a moth-luring chemical in bolas spiders. More recent technological developments have enabled researchers to uncover and quantify deceptive visual, olfactorial and vibrational signals. The evolution of these signals is intriguing as a close association between spider and prey is often required. While deceptive colour signals seem to be generic, targeting a wide range of potential prey, deception via vibrational and olfactorial signals is often more specific. The specificity of the signal in turn requires a considerable degree of plasticity in order for the spider to target more than one prey type. Our review of deceptive signals makes use of several well-studied systems with fascinating plasticity and behavioural flexibility in the deployment of the signal. The evolution of deceptive signals. Signals contain information that modulates the behaviour of the individuals that receive them (Bradbury and Vehrencamp, 1998). Some signals exploit pre-existing sensory biases in receivers. The neural responses to these signals may have evolved under different contexts but signal traits that exploit these biases are thought to be most effective (Endler and Basolo, 1998, Johnstone, 1997).