Phylogeny, systematics and rarity assessment of New Zealand endemic Saphydrus beetles and related enigmatic larvae (Coleoptera : Hydrophilidae : Cylominae)

摘要: The New Zealand endemic beetle genus Saphydrus Sharp, 1884 (Coleoptera : Hydrophilidae : Cylominae) is studied in order to understand its phylogenetic position, species-level systematics, biology and distribution, reveal reasons for rarity. first complete genus-level phylogeny of Cylominae based on two mitochondrial (cox1, 16S) nuclear genes (18S, 28S) covering 18 19 genera the subfamily reveals as an isolated lineage situated a clade with Cylorygmus (South America), Relictorygmus Africa) Eurygmus (Australia). DNA used associate larval morphotypes Saphydrus: one them represents larvae S. suffusus 1884; other, characterised by unique characters head prothorax morphology, revealed sister but not closely related Saphydrus. It described here Enigmahydrus, gen. nov. single species, E. larvalis, sp. nov., whose adult stage remains unknown. includes five which (S. moeldnerae, tanemahuta, nov.) are new. Larvae Enigmahydrus larvalis illustrated detail DNA-identified specimens. Candidate obesus tanemahuta diagnosed. Specimen data evaluate range, altitudinal seasonality population dynamics over time all species. Strongly seasonal occurrence adults combined other factors (winter obesus, at high altitudes tanemahuta) hypothesised primary reason rarity By contrast, underwent strong decline number size since 1970s currently known from single, locally limited population; we propose ‘nationally threatened’ status this http://zoobank.org/urn:lsid:zoobank.org:pub:28D87163-29E8-418C-9380-262D3038023A