Calonecrinae represent a unique but small subfamily of Nitidulidae that is endemic to South Asia. Their habitats, the South Asian lowland forests, are under the imminent threat of degradation, posing a risk of rapid extinction for these species in their specific locales. Despite the looming threat to their existence, our understanding of this enigmatic group remains limited. We conducted an examination of museum and newly collected specimens, alongside a review of the literature, leading to the discovery of a new species, Calonecrus mindanaoensis, from Mindanao, Philippines. For the first time, the morphology of all immature stages of the Calonecrinae was described, with detailed photographs including SEM images. Additionally, their natural history was uncovered for the first time, revealing that all life stages are uniquely adapted to spending their entire life cycle within sticky resin. We re-evaluated the phylogenetic placement of the Calonecrinae by constructing a phylogenetic tree based on the mitochondrial genome. Calonecrinae are positioned within the Epuraeinae clade and show significant affinity with the genus Trimenus. Consequently, this study proposes reclassifying Calonecrinae as Calonecrini stat nov, an extremely modified tribe within the Epuraeinae.

The Nitidulidae includes 10 subfamilies and over 350 genera and 4500 species and is the largest family in Cucujoidea. We place the enigmatic subfamily Calonecrinae into the internal relationship of Nitidulidae, a comprehensive molecular phylogenetic analysis was performed using five gene regions (COI, 28s, CAD, H3, Wingless) for 80 taxa. We included 73 ingroup taxa representing nine of the ten currently recognized subfamilies of Nitidulidae and 7 outgroups. The phylogenetic results are consistent with prior molecular studies, that include a polyphyletic Nitidulinae with the inclusion of Meligethinae and Cillaeinae and that the Calonecrinae is sister taxon to Epuraeinae. Ancestral state reconstruction of feeding behavior indicates that stem group nitiduilds were most probably sap-feeding with transitions to other feeding types independently derived multiple times.