Lifespan of groups of Cardiocondyla queens.

Groups of queens, which all mated with winged males (right, brown symbols), lived on average significantly longer than groups of queens, which all mated with a wingless male (left, yellow symbols), independent of whether queens were reared under stressed (filled dots) or unstressed conditions (open rectangles). Black dots indicate censored data, e.g., groups of queens still alive at the end of the experiment.