Claustral colony founding is limited by body condition: experimental feeding increases brood size of Lasius niger queens (Hymenoptera: Formicidae)

Abstract Ants can found colonies in different ways. One is by claustral colony foundation, when fertilized queens typically have enough nutrients reserved in their bodies to raise the first ‘nanitic’ worker generation without any foraging activity. This colony-foundation strategy evolved in response to selective pressures (e.g. predators), but it limits the number of nanitic workers. We, therefore, assumed that fed queens might initially rear more nanitic workers, although feeding might also be associated with risks and stress. In this study, we analysed the effects of stress and different diets during the colony-foundation period on the success of colony founding by claustral black garden ant Lasius niger (Hymenoptera: Formicidae) queens. Our findings confirm that regularly fed claustral ant queens raise more pupae and workers, reflecting that limited brood size is a cost of safety behaviour for claustral ant queens. There is another notable aspect of our findings for laboratories: in order to maximize the size of the nanitic worker generation, they can feed claustral ant queens with crickets.