Illuminating the Lampyridae: A step towards a large-scale molecular phylogeny of the fireflies

Fireflies are one of the most captivating groups of organisms due to their bioluminescence. However, this behavior although well studied behaviorally, is not well understood from an evolutionary perspective (e.g., How many origins does bioluminescence have?). A total evidence phylogenetic study (morphology and molecules combined) of the family is lacking.  Such a phylogeny has the potential to resolve competing theories of the monophyly of subfamilies and the position of several taxa that may or not be members of Lampyridae (Pterotinae and Ototretinae). Further, an accurate phylogenetic reconstruction is crucial to understanding the interactions of adult sexual signaling systems at both the morphological and the molecular level. Of interest in this study is the hypothesized ancestral sexual signal system modality.

We use multiple phylogenetic methods to recontsruct the phyolgeny of >100 lampyrid species. This data is based on six molecular markers: 12S, 16S, 18S, 28S, COI and Wingless, and ~400 morphological characters.  

We recovered all subfamilies except Lampyrinae and Ototretinae as monophyletic (Photurinae sitting within the Lampyrinae; Ototretinae rendered paraphyletic). The Ototretinae are recovered as sister to a clade comprised of Cyphonocerinae + Pterotinae + Luciolinae. We find that the ancestral communcation modality is pheromone only, with two - three gains of adult bioluminescence and 6-7 subsequent losses.