Population and colony structure of the ant Cardiocondyla venustula: the consequences of male mating monopolies

The ant genus Cardiocondyla is characterized by wingless males, which in species from Southeast Asia and Wallacea engage in fatal fighting for the monopolization of female sexuals in their natal nests but are mutually tolerant in species from Central Asia and Southern Europe. Taxa of the African C. shuckardi-complex are the sister group of the clade with tolerant males and might therefore be particularly helpful for retracing the evolution of male behavior. Indeed, males of C. venustula appear to show an intermediate behavior between fighting and complete tolerance in that they defend territories inside their natal nests. This phenomenon is novel for social insects and opens new perspectives for research on sexual selection in ants. We intend to determine if territories differ in quality (e.g., probability of mating with a female sexual), if males form hierarchies based on physical properties to obtain particularly good territories, and if female sexuals choose among the co-occurring males. Furthermore, we will use genetic markers to determine the consequences of male territoriality on the genetic colony and population structure.Our studies will help to better understand the evolution of reproductive tactics in the ant genus Cardiocondyla and complement our knowledge on inter- and intrasexual selection in insects in general.