Ecological and evolutionary aspects of learning in phytophagous insects

In phytophagous insects, emphasis has been on learning in relation to the acquisition of food, but there is also an array of work on mate acquisition, recognition of competitors and establishment of home range. Host stimuli involved in learning are noted. Types of learning include habituation, associative learning, aversion learning and induction of preference. Ecological implications of each type are examined, and the possible integration of learning mechanisms is indicated. There are a number of programmed elements of learning, eg imprinting, where restriction to a limited set of stimuli and motor patterns in highly specific contexts probably has an adaptive function. The adaptive functions of learning and memory are embraced by the non-mutually exclusive neural economy and environmental unpredictability hypotheses. There is little evidence that learning has undergone adaptive evolutionary change in phytophagous insects, though the potential for such change probably exists. -P.J.Jarvis