Léa Zinck1, Riviane R. Hora2, Claudie Doums3, and Pierre Jaisson1. (1) Laboratoire d’Ethologie Expérimentale et Comparée, Université Paris Nord, ParisXIII, 99 avenue J. B. Clément, 93430, Villetaneuse, France, (2) Laboratorio de Mirmecologia, CEPEC/CEPLAC, C.P. 45600-000, Itabuna, Bahia, Brazil, (3) Laboratoire Fonctionnement et Evolution des Systèmes Ecologiques, Université Pierre et Marie Curie, ParisVI, 7 quai St Bernard, 75252, Paris, France
In most social insects, colony boundaries are well delimited and associated with behavioral boundaries to maintain fundamental colony unit. However, in some polydomous or unicolonial species defining the colony unit can be difficult. We studied nest aggregation in patch of an ectatommine ant Ectatomma tuberculatum characterized as a dominant species in the mosaic of arboreal ants in Neotropical habitats to investigate how colony unit can be linked to this nest distribution. We first examined the behavioral relationship between nests through aggression tests and territoriality experiments conducted in the field. Second, a population genetic study using microsatellite markers was conducted both between and within patches. We only found aggressive behaviors between workers from different patches and this absence of aggression between non nestmate workers (i.e. from different nests) of a same patch was associated in the field to the share of a same foraging area. Interestingly, the population genetic structure revealed a significant genetic differentiation between nests of a given patch (mean Fst = 0.13) and a significant isolation by distance within patches likely due to the mode of colony foundation by budding. Altogether, our results suggest the existence of an open recognition system in E. tuberculatum linked to a patch functional level of organization. Stability of such system appears to be due to genetic structuration of patch resulting from colony budding and limited dispersal of sexuals. This structuration of nests in patch thus corresponds to actual colony unit of E. tuberculatum and may favor in turn his ecological dominance in the mosaic of arboreal ants.
See more of Posters and Exhibits Group A. - continued
See more of Poster Presentations
See more of The IUSSI 2006 Congress