Unrelated helpers in a social insect

• Published in: Nature (London) Vol. 405; no. 6788; pp. 784 - 787
• Main Authors: Queller, David C, Zacchi, Francesca, Cervo, Rita, Turillazzi, Stefano, Henshaw, Michael T, Santorelli, Lorenzo A, Strassmann, Joan E
• Format: Journal Article
• Language: English
• Published: London Nature Publishing 15.06.2000; Nature Publishing Group
• Subjects: Animal behavior; Animal ethology; Animals; Biological and medical sciences; Female; Fundamental and applied biological sciences. Psychology; Genes; Genetic markers; Genetics; Helping Behavior; Hymenoptera; Insects; Male; Polistes dominulus; Protozoa. Invertebrata; Psychology. Psychoanalysis. Psychiatry; Vertebrates; Vespidae; Wasps - physiology; Insecta; Biological marker; Social insect; Reproduction; Social behavior; Queen insect; Helping behavior; Kinship coefficient; Arthropoda; Microsatellite DNA; Vespidae; Hymenoptera; Invertebrata; Aculeata
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/35015552

High-resolution genetic markers have revolutionized our understanding of vertebrate mating systems, but have so far yielded few comparable surprises about kinship in social insects. Here we use microsatellite markers to reveal an unexpected and unique social system in what is probably the best-studied social wasp, Polistes dominulus. Social insect colonies are nearly always composed of close relatives; therefore, non-reproductive helping behaviour can be favoured by kin selection, because the helpers aid reproductives who share their genes. In P. dominulus, however, 35% of foundress nestmates are unrelated and gain no such advantage. The P. dominulus system is unlike all other cases of unrelated social insects, because one individual has nearly complete reproductive dominance over subordinates who could have chosen other reproductive options. The only significant advantage that subordinates obtain is a chance at later reproduction, particularly if the queen dies. Thus, P. dominulus societies are functionally unlike other social insects, but similar to certain vertebrate societies, in which the unrelated helpers gain through inheritance of a territory or a mate.