Predation of Dione juno juno (Lepidoptera: Nymphalidae) by Erythemis vesiculosa (Odonata: Libellulidae) in a Caatinga–Atlantic Forest ecotone, with a review of butterfly predation by dragonflies

Predation events linking aquatic predators to terrestrial prey can shape energy flow in ecotonal landscapes but remain poorly documented. Here we report the first record of predation on the heliconiine butterfly Dione juno juno (Lepidoptera: Nymphalidae) by Erythemis vesiculosa (Fabricius, 1775) (Odonata: Libellulidae) in a Caatinga–Atlantic Forest ecotone in Bahia, Brazil. On 6 October 2024, at the campus of the State University of Feira de Santana (northeastern Brazil), we photo-documented an adult Erythemis (∼38 mm) perched on shrubby vegetation handling an adult D. j. juno (∼32 mm). The dragonfly grasped the butterfly with its forelegs and consumed the head and anterior thorax—prey-handling behavior typical for libellulids. The event occurred within an anthropized mosaic of shrub–herb vegetation and forest fragments. This observation expands current knowledge of the opportunistic diet of Erythemis, reinforces its role as a generalist predator of flying insects, and underscores the value of ecotones as natural laboratories to study insect predator–prey interactions. Given ongoing habitat fragmentation and climate change in these transition zones, opportunistic, photo-vouchered records such as this can complement systematic surveys and help quantify cross-habitat predation pressure on Lepidoptera. In addition, we provide a brief review of published cases of butterfly predation by dragonflies across different biogeographical contexts, which places our record into a broader comparative framework and highlights the underreporting of this phenomenon.