Host-plant phenology mediates facultative ant mutualism in the rare butterfly, Celastrina humulus (Lepidoptera: Lycaenidae).

Host-plant phenology can directly and indirectly mediate the abundance of insect herbivores. Our objective was to determine how host-plant flowering phenology shapes a facultative ant-lycaenid mutualism. The focus of our research was the hops azure, Celastrina humulus Scott & D.