Revision of Nicrophorus in part: new species and inferred phylogeny of the nepalensis-group based on evidence from morphology and mitochondrial DNA (Coleoptera : Silphidae : Nicrophorinae)

摘要

Carrion beetles of the genus Nicrophorus Fabricius, 1775 (Silphidae) are well known for their biparental brood care and monopolisation of small vertebrate carcasses in subterranean crypts. Although the taxonomy of New World species has received modern attention, the fauna of Asia, primarily of the nepalensis-group of species, has not. Herein we revise this species-group and describe as new the following seven species: Nicrophorus charon Sikes & Madge (Sulawesi), Nicrophorus herscheli Sikes & Madge (Sumatra), Nicrophorus insignis Sikes & Madge (Flores Island), Nicrophorus melissae Sikes & Madge (Nepal, Bhutan), Nicrophorus reticulatus Sikes & Madge (Guadalcanal), Nicrophorus schawalleri Sikes & Madge (Gansu, Shaanxi, Sichuan Province) and Nicrophorus trumboi Sikes & Madge (Nepal, Bhutan). We obtained a preliminary phylogeny using morphology and mtDNA (COII). This was inferred using maximum likelihood and Bayesian methods with the Mkv and GTR+I+G models (parsimony was rejected by the Akaike information criterion for being excessively parameter-rich). The phylogenetic signal in the morphological dataset was not strong and results were confounded by a ‘long-branch’ species, N. reticulatus. The signal was stronger in the combined dataset and the COII-only dataset. The molecular phylogeny supported the new status of species N. trumboi and N. melissae. Support was found for a mainland origin of the group with subsequent radiations into the Malay Archipelago.