Flashy Neighbours: Psilocladus mantilleri Zeballos, Nunes, Silveira & Rosa, sp. nov., the First Termitariophile Firefly Larva (Coleoptera: Lampyridae)

Fireflies are semelparous beetles whose immature stages are largely unknown. The comparatively few larvae known span diverse ecological niches, such as ground‐dwellers, aquatic (freshwater or marine), semi‐aquatic and arboreal. Psilocladus costae Vaz, Silveira & Rosa, 2020—a bromeliad dweller—is the only species of its genus and subfamily in which immature stages were studied. We collected firefly larvae in the Brazilian Cerrado inside termite nests and in the underground vaults surrounding them. These larvae were raised in the lab and identified as a new Psilocladus species, described herein as Psilocladus mantilleri Zeballos, Silveira, Nunes & Rosa, sp. nov. Adult males of the new species can be diagnosed by the following combination of adult characters: antenna rami, pronotum, legs, elytra and scutellum yellowish; basal half of submentum strongly constricted; abdomen with light organ on sternum VI, as wide as 3/5 sternum width; and phallobase with apical margin notched at the central third. The larva differs from that of P. costae in its tergites pale yellow to ochre, sternites paler, abdominal tergite IX semicircular and light organs indistinct. The similarity between Psilocladus and photurine larvae is interpreted in the context of the close affinities between these two subfamilies. Given the lack of clear morphological adaptations for termitophily, we hypothesize that this species is an opportunistic commensal, probably relying on termite nests occasionally for shelter and potentially preying on their inquilines.