A Deadly Ride: The Interaction Between the Tortoise Beetle <scp> <i>Botanochara impressa</i> </scp> and the Parasitoid Wasp <i>Emersonella niveipes</i>

ABSTRACT Parasitoid insects can significantly influence the dynamics of terrestrial ecosystems due to their interactions with phytophagous insects. Tortoise beetles (Cassidinae s. str. , Coleoptera, Chrysomelidae) are one of the most parasitized groups of Coleoptera. Emersonella Girault (Hymenoptera, Eulophidae), which are egg parasitoid wasps, are among the main natural enemies of Neotropical tortoise beetles. Some species of this genus use phoresy strategies to facilitate their encounter with tortoise beetle eggs; however, few studies have been conducted on this behaviour. In this study, we found a female wasp of Emersonella niveipes (Eulophidae) on the elytra of a female Botanochara impressa (Cassidinae s. str. , Chrysomelidae). During our observations, the wasp was transported on the beetle's elytra for most of the time, leaving only for a few seconds to land on the B. impressa eggs, and then returning to the beetle's back. This behaviour continued for 12 consecutive hours until the wasp died. Seven eggs laid by the female beetle had E. niveipes wasps coming out of them, confirming the host‐parasitoid interaction. This is the first record of an egg parasitoid for B. impressa and expands the list of known hosts used by E. niveipes . It is also the third record of phoretic behaviour in this species of Emersonella with a different species of Cassidinae.