INVESTIGADORES
LOPEZ DE CASENAVE Javier Nestor
artículos
Título:
Polyandry in two South American harvester ants
Autor/es:
R. G. POL; J. LOPEZ DE CASENAVE; H. FELDHAAR; F. A. MILESI; J. GADAU
Revista:
INSECTES SOCIAUX
Editorial:
Birkhauser Verlag
Referencias:
Lugar: Basel; Año: 2008 vol. 55 p. 91 - 97
ISSN:
0020-1812
Resumen:
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Although monandry (single mating) is the ancestral state in
social hymenopteran insects, effective mating frequencies greater than 2 have
been confirmed for a fair amount of ant species: Cataglyphis cursor, the leaf-cutters
of the genera Atta and Acromyrmex, army ants of the genera Eciton, Dorylus,
Aenictus and Neivamyrmex, and some North American seed Harvester species of the
genus Pogonomyrmex. This last genus spreads throughout open arid habitats from
Patagonia to southwestern Canada. Whereas some North American Pogonomyrmex species
are thoroughly studied, we know much less about these ants in South America.
The objective of this study was to estimate the effective mating frequency of Pogonomyrmex
inermis and P. pronotalis, two Pogonomyrmex sensu stricto species from the
central Monte desert of Argentina. A total of 477 P. pronotalis workers from 24
colonies and 402 P. inermis workers from 20 colonies were analyzed using six and
four highly polymorphic microsatellites, respectively. The multilocus analysis
revealed that all colonies were monogynous and all queens multiply-mated. The
effective mating frequency was 8.75 and 6.52 for queens of P. pronotalis and P.
inermis, respectively; those values increased up to 15.66 and 9.78,
respectively, when corrected for sampling errors. This is the first
demonstration that queens in at least some members of the South American Pogonomyrmex
sensu stricto are strictly polyandrous, with mating numbers per queen at least
as high as those previously found for North American species. We suggest that
multiple mating probably arose early in the evolution of the genus Pogonomyrmex
and may be the basis of its ecological success and wide distribution.