Apharitis lilacinus life cycle showing larval and pupal associations with Crematogaster hodgsoni ants. Structures of the specialized larval organs that mediate caterpillar–ant interactions are depicted on the right based on our MicroCT data (Figs. 2, 3, 4). Blue arrow in the nectar gland shows the external opening of the gland. The life stages, interactions, and MicroCT-derived 3D volumes of caterpillar and pupa of A. lilacinus are animated in Supplementary Movie 1. Image courtesy for egg: Nitin Ravikanthachari; pupa and ant-caterpillar/pupa interaction: Ashok Sengupta and G. S. Girish Kumar.