While hoeneybees represent model organisms with complex social structures within populations, a comprehensive understanding of developmental regulation in relation to sexual development as well as cast determination still remains. Despite decades of research explanations on mechanistics underlying complementary sex determination remain an unresolved pussle and the link between dietary differences and female phenopypic plasticity has yet to be indentified. In the present PhD projekt different aspects of both types of development was explored using a combination of high throughourt sequencing and functional molecular biological techniques to advance current interpretations of heneybee development