Multiply Mating Males in Gnamptogenys striatula Mayr (Hymenoptera, Formicidae) D. Allard & M. Van Hulle & J. Billen & B. Gobin Revised: 3 August 2007 / Accepted: 25 June 2008 / Published online: 22 July 2008 # Springer Science + Business Media, LLC 2008 Abstract Multiply mating ant males are rare, because in most ant species, multiple mating opportunities for males are scarce. Gnamptogenys striatula is an exception to this rule, as intranidal mating offers protection and a local female-biased sex ratio. In a behavioral experiment, we confirm the males’ ability to inseminate several receptive workers, with four females being the observed maximum. Keywords Formicidae . males . multiple mating . insemination Introduction The role of males in social Hymenoptera biology has long been neglected, as these males do not take part in the daily household tasks of a colony. However, in recent years, new fields of study have emerged in which males do play an important role, like sexual selection and sexual conflict (see the recent review by Boomsma et al. 2005). Detailed studies of male life history and mating systems are now needed to test these sexual selection hypotheses. This study shows that males of the polygynous ant Gnamptogenys striatula Mayr can inseminate several females. While multiple mating by females has been well documented (Strassmann 2001), multiple male mating is exceptional in ants (Bourke and Franks 1995), with the best documented example being Cardiocondyla J Insect Behav (2008) 21:476–480 DOI 10.1007/s10905-008-9143-2 D. Allard is a Research Assistant for the Fund of Scientific Research—Flanders. D. Allard : M. Van Hulle : J. Billen (*) : B. Gobin Zoological Institute, University of Leuven, Naamsestraat 59, 3000 Leuven, Belgium e-mail: johan.billen@bio.kuleuven.be B. Gobin Zoology Department, pcfruit Research, Fruittuinweg 1, 3000 Leuven, Belgium