Figure 1. Different modes of colony foundation of C. obscurior queens.

Under favourable conditions (left), wingless males (yellow male symbol) develop and mate with virgin queens (black female symbol), which start egg laying within the colony, assisted by workers (grey circles) and other queens (black female symbol). New colonies are founded by several individuals, which leave the mother colony and colonize new nest sites close by. Under stressful conditions (right), winged disperser males develop (brown male symbol) and mate with the virgin queens in and away from the maternal nest. Under such conditions, young queens leave the colony to colonize new nest sites in better environmental conditions and found either alone or together with other queens.