Queen-queen competition and reproductive skew in a Cardiocondyla ant

Abstract

Queens and female sexuals of the Southeast Asian ant Cardiocondyla sp. engage in aggressive interactions. By biting and violently antennating female sexuals, queens appear to prevent them from shedding their wings and presumably also from starting to lay haploid eggs. Aggression among dealate queens apparently results in the establishment of reproductive rank orders with considerable differences in offspring production among individual nestmate queens, as visualized by the pronounced color polymorphism of this taxon. Reproductive skew ranged from complete monopolization of both worker and female sexual production to more or less equal partitioning of reproduction. Division of reproduction was associated with variation in the location of queens close to or away from the center of the brood pile, which again appeared to be caused by queen-queen antagonism.

Between-Year Variation in Population Sex Ratio Increases with Complexity of the Breeding System in Hymenoptera

“…First, reproductive skew among cobreeding queens occurs in many multiple-queen ant species (Ross 1988;Rüppell et al 2002;Hannonen and Sundström 2003;Fournier et al 2004;Hammond et al 2006;Keller 2007a, 2007b;Yamauchi et al 2007). Between-year variation in reproductive skew could alter colony kin structure and thus sex ratio decisions (Bourke 2001).…”

Life-history evolution in ants: the case ofCardiocondyla

“…By contrast, genetic data show that queens of monogynous species produce offspring sired by multiple fathers [46][47][48]. Polyandry might retain genetic variability despite of predominant inbreeding [79].…”

Lethal sibling rivalry for nest inheritance among virgin ant queens

“…This has led to a peculiar reversal of the usual sequence of reproduction in insect societies, in that males are among the first individuals to emerge in freshly founded multi-queen societies (Yamauchi et al 2006). In addition, in medium-sized colonies, adult nestmate queens establish social and reproductive hierarchies by biting and antennal boxing (Yamauchi et al 2007). …”

“…The small colonies of the southeast Asian ant Cardiocondyla ''latifrons'' (provisional name; species to be described by B. Seifert) usually consist of a few dozen workers (Yamauchi et al 2007;S. Frohschammer, personal communication) and one or several queens.…”

“…We hypothesized that virgin queens compete for the inheritance of the nest after the death of their mother(s) and that this competition is particularly strong in small colonies with a low ''queen carrying capacity.'' As preliminary observations suggested some aggression among virgin queens (Yamauchi et al 2007), we conducted a more thorough analysis of their behavior in queenless colonies.…”