Predatory success in the water stick insect: The role of visual and mechanical stimulations after moulting

The more foreleg femur and claw movements that a water stick insect, Ranatra linearis, performs during the 4-h period following a moult, the higher will be its subsequent strike efficiency. The amount of movement is influenced by external factors such as the presence of prey or light. The experiments reported here show that the absence of visual cues during the post-moult periods impairs subsequent performance, but not as much as the absence of both visual and mechanical cues. Perception of mechanical stimuli only during that period subsequently influences the accuracy of simple type strikes elicited when prey is near the forelegs; whereas perception of visual stimuli subsequently improves the accuracy of more complex predatory movements.