A new species of Petalacmis firefly from Bolivia, with a key to species (Coleoptera, Lampyridae)

Olivier, 1908 is a poorly known genus of firefly endemic to South America and is currently the only member of the subfamily Lampyrinae, tribe Lampyrini known to occur on the continent. Here, we describe a new species, from Bolivia and compare it to the two other described species in the genus. A key to species based on male traits, as well as illustrations of morphological features, are given in detail for the first time. We present unique, previously neglected traits of species and compare them to other Lampyrinae.