Learning and memory, defined as the acquisition and retention of neuronal representations of new information, are ubiquitous among insects. Recent research indicates that a variety of insects rely extensively on learning for all major life activities including feeding, predator avoidance, aggression, social interactions, and sexual behavior. There is good evidence that individuals within an insect species exhibit genetically based variation in learning abilities and indirect evidence linking insect learning to fitness. Although insects rely on innate behavior to successfully manage many types of variation and unpredictability, learning may be superior to innate behavior when dealing with features unique to time, place, or individuals. Among insects, social learning , which can promote the rapid spread of novel behaviors, is currently known only from a few well-studied examples in social Hymenoptera. The prevalence and importance of social learning in insects are still unknown. Similarly, we know little about ecological factors that may have promoted enhanced learning abilities in insects, and whether learning has significantly contributed to speciation in insects.

This review focuses on five key evolutionary issues pertaining to animal cognition, defined as the neuronal processes concerned with the acquisition, retention, and use of information. Whereas the use of information, or decision making, has been relatively well examined by students of behavior, evolutionary aspects of other cognitive traits that affect behavior, including perception, learning, memory, and attention, are less well understood. First, there is ample evidence for genetically based individual variation in cognitive traits, although much of the information for some traits comes from humans. Second, several studies documented positive association between cognitive abilities and performance measures linked to fitness. Third, information on the evolution of cognitive traits is available primarily for color vision and decision making. Fourth, much of the data on plasticity of cognitive traits appears to reflect nonadaptive phenotypic plasticity, perhaps because few evolutionary analyses of cognitive plasticity have been carried out. Nonetheless, several studies suggest that cognitive traits show adaptive plasticity, and at least one study documented genetically based individual variation in plasticity. Fifth, whereas assertions that cognition has played a central role in animal evolution are not supported by currently available data, theoretical considerations indicate that cognition may either increase or decrease the rate of evolutionary change.

Ecological research in the past few decades has shown that most animals acquire and respond adaptively to information that affects survival and reproduction. At the same time, neurobiological studies have established that the rate of information processing by the brain is much lower than the rate at which information is encountered in the environment, and that attentional mechanisms enable the brain to focus only on the most essential information at any given time. Recent integration of the ecological and neurobiological approaches helps us to understand key behaviours with broad ecological and evolutionary implications. Specifically, current data indicate that limited attention affects diet choice and constrains animals' ability simultaneously to feed and attend to predators. Recent experiments also suggest that limited attention influences social interactions, courtship and mating behaviour.

2003. Crab spiders affect flower visitation by bees. -Oikos 101: 157-163.In a field experiment, the bumblebee, B. ternarius, visited milkweed patches harboring crab spiders, Misumena 6atia, at a lower frequency than patches free of crab spiders, and honeybees showed a similar but non-significant trend. Two other bumblebee species, B. terricola and B. 6agans, did not avoid the spider patches. The latter two species are larger than B. ternarius and honeybees and suffer lower crab-spider predation. As far as we know, this is the first field study documenting negative effects of predators on flower visitation rate by pollinator populations. Our study suggests that pollinator response to predation may influence pollinator-plant interactions.

Studies on the ecology of animal memory have focused on the benefits of memory while implicitly assuming that there are costs as well. Here I discuss probable costs of memory by relying on knowledge from molecular biology and physiology, which indicates that the maintenance of accurate information in animals is an active and costly process of maintenance and repair. Redundancy probably plays a key role in ensuring a high level of accuracy; its cost is in terms of additional tissue, which increases body mass and energetic expenditure. Examining the magnitude and cost of redundancy at the neurobiological and behavioral levels can help us understand the cost of memory in particular and cognitive abilities in general.