A novel heptacyclic alkaloid, for which we coin the name chilocorine, was isolated from a ladybird beetle, Chilocorus cacti. It has a unique structure made up of two tricyclic substructures, 2-methylperhydro-9b-azaphenalene and 3,4-dimethyloctahydro-8b-azaacenaphthylene. The proposed structure is based on mass spectrometric, ultraviolet spectroscopic, and NMR evidence. © 1994.