The Lampyrinae are a large subfamily of fireflies (Lampyridae). The exact delimitation, and the internal systematics, are a matter of debate; for long this group was used as a "wastebin taxon" to hold any fireflies with insufficiently resolved relationships. Regardless, they are very diverse even as a good monophyletic group, containing flashing and continuous-glow fireflies from the Holarctic and some tropical forms too. The ancestral Lampyrinae probably had no or very primitive light signals; in any case several modern lineages have returned to the pheromone communication of their ancestors independently it seems.