Ant-kissing leaf beetles: Behavior and adult morphology of the myrmecophilous leaf beetle Hockingia curiosa (Coleoptera: Chrysomelidae: Camptosomata)

Leaf beetles (Chrysomelidae) are predominantly phytophagous but some species are associated with ant colonies during specific life stages. The leaf beetle species Hockingia curiosa was documented within domatia of myrmecophytic plants (Vachellia drepanolobium) inhabited by aggressive ant colonies (Crematogaster mimosae) over 60 years ago in Tanzania. Hockingia curiosa has been considered the most morphologically specialized leaf beetle species based on its peculiar and specific morphology, although behavioral observations of living individuals have been lacking. The rediscovery of H. curiosa in Kenya (new country record) allowed for the first in-depth observations of living individuals. Laboratory-based studies revealed intricate interactions with host ants, including grooming behaviors and trophallaxis, similar to those observed in other highly specialized myrmecophilous arthropods. Additionally, we provide a redescription of its morphological characteristics and discuss their potential functions in the context of myrmecophily.