Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: August 20, 1996
Publication Date: N/A
Interpretive Summary: Ants have developed a formidable array of defenses against microbes, parasites and predators. Many of these defensive behaviors are initiated when an intruder is recognized as non-nestmate by resident workers. Nestmate recognition represents the first line of colony defense. This review focuses on the basic elements of ant nestmate recognition. The recognition process is separated into cues, template, and behavioral response. The cues are the chemicals sensed by individuals that initiate a recognition response, usually aggression. The template is the neural imprint of the cues. Recognition as nestmate occurs if the cues of the "intruder" match the template of the "resident". If they do not match, then aggression occurs. Models of the recognition process are presented that explain why, for example, the single queen fire ant colonies are highly aggressive toward fire ants from other colonies, whereas workers from colonies with multiple queens are not aggressive toward fire ants from other colonies. This review clearly points out that correlative data has been used erroneously to state that cuticular hydrocarbons are nestmate recognition cues for several ant species. Some microbes, parasites and predators are able to overcome the recognition process.
Technical Abstract: All ant species are highly eusocial. The altruistic (or nepotistic) behavior associated with ants and other eusocial insects characterizes kin selection. To achieve kin selection there must be kin recognition. This connection has provided the driving force for much of the large volume of research over the past decade concerned with kin and nestmate recognition. From a practical point of view ants have developed a formidable array of semiochemical and nonchemical defenses that can be active or passive. The many active defensive behaviors are initiated when an intruder is recognized as non-nestmate by resident workers. Thus, nestmate recognition represents the first line of defense for a colony. Knowledge of nestmate recognition is essential for a comprehensive understanding of both ant defenses and the organisms (symphiles) that have broken the recognition code and are able to infiltrate ant colonies and exploit colony resources. These areas of research may provide the basis of innovative control strategies for pest ant species. This review critically evaluates ant nestmate recognition. The source of cues, neural templates, and behavioral responses are explored. Working models are developed to explain differences in monogyne and polygyne recognition processes. The nature of the recognition cues is probably very complex; however, dogma has developed that has focused erroneously on cuticular hydrocarbons as the cues. This has been based only on correlative evidence rather than direct evidence.