Interrelationships of Staphyliniform groups inferred from 18S and 28S rDNA sequences, with special emphasis on Hydrophiloidea (Coleoptera, Staphyliniformia)

The series Staphyliniformia is one of the mega‐diverse groups of Coleoptera, but the relationships among the main families are still poorly understood. In this paper we address the interrelationships of staphyliniform groups, with special emphasis on Hydrophiloidea and Hydraenidae, based on partial sequences of the ribosomal genes 18S rDNA and 28S rDNA. Sequence data were analysed with parsimony and Bayesian posterior probabilities, in an attempt to overcome the likely effect of some branches longer than the 95% cumulative probability of the estimated normal distribution of the path lengths of the species. The inter‐family relationships in the trees obtained with both methods were in general poorly supported, although most of the results based on the sequence data are in good agreement with morphological studies. In none of our analyses a close relationship between Hydraenidae and Hydrophiloidea was supported, contrary to the traditional view but in agreement with recent morphological investigations. Hydraenidae form a clade with Ptiliidae and Scydmaenidae in the tree obtained with Bayesian probabilities, but are placed as basal group of Staphyliniformia (with Silphidae as subordinate group) in the parsimony tree. Based on the analysed data with a limited set of outgroups Scarabaeoidea are nested within Staphyliniformia. However, this needs further support. Hydrophiloidea s.str., Sphaeridiinae, Histeroidea (Histeridae + Sphaeritidae), and all staphylinoid families included are confirmed as monophyletic, with the exception of Hydraenidae in the parsimony tree. Spercheidae are not a basal group within Hydrophiloidea, as has been previously suggested, but included in a polytomy with other Hydrophilidae in the Bayesian analyses, or its sistergroup (with the inclusion of Epimetopidae) in the parsimony tree. Helophorus is placed at the base of Hydrophiloidea in the parsimony tree. The monophyly of Hydrophiloidea s.l. (including the histeroid families) and Staphylinoidea could not be confirmed by the analysed data. Some results, such as a placement of Silphidae as subordinate group of Hydraenidae (parsimony tree), or a sistergroup relationship between Ptiliidae and Scydmaenidae, appear unlikely from a morphological point of view.     

毛牙甲科在中国的首次发现及凹缘角牙甲再描述(鞘翅目,牙甲总科,毛牙甲科)

报道中国鞘翅目1新纪录科1新纪录种,即毛牙甲科Spercheidae和凹缘毛牙甲Spercheus emarginatus(Schaller).共计2头雄性和1头雌性采自黑龙江密山,对其进行了再描述.该虫已知分布于欧洲中西部和南部、俄罗斯南部和远东地区、亚洲中部和东部区,目前仅在中国东北地区发现.     

On the constitution and phylogeny of Staphyliniformia (Insecta: Coleoptera)

The Staphyliniformia is one of the most diverse lineages of Coleoptera, with representatives occupying every conceivable non-marine niche. Phylogenetic relationships among its varied families and lower taxa have defied resolution. The problem has been further complicated by the recent suggestion that another major coleopteran series, Scarabaeiformia, is derived from within it. Here we present the first phylogenetic analyses, based on 18S rDNA sequences and morphological data, to explicitly examine this possibility. Thorough evaluation of alternative alignments and tree construction methods support the contention that Scarabaeiformia is derived from within Staphyliniformia. Though the analyses yielded strong support for few family level groupings within the expanded Staphyliniformia, they conclusively support a close relationship between Hydraenidae and Ptiliidae, which has often been debated. The primary factor hindering additional resolution appears to be the inconsistent rate of divergence in 18S among these taxa.     

A long-living species of the hydrophiloid beetles: Helophorus sibiricus from the early Miocene deposits of Kartashevo (Siberia, Russia)

The recent hydrophiloid species Helophorus (Gephelophorus) sibiricus (Motschulsky, 1860) is recorded from the early Miocene deposits of Kartashevo assigned to the Ombinsk Formation. A detailed comparison with recent specimens allowed a confident identification of the fossil specimen, which is therefore the oldest record of a recent species for the Hydrophiloidea. The paleodistribution as well as recent distribution of the species is summarized, and the relevance of the fossil is discussed. In addition, the complex geological settings of the Kartashevo area are briefly summarized.     

Contributions to molecular systematics of water scavenger beetles (Hydrophilidae,Coleoptera)

Phylogenetic relationships within Hydrophilidae were examined by analyses of separate and combined nuclear and mitochondrial markers (28S rRNA, 18S rRNA, 16S rRNA, 12S rRNA, COI and COII genes). The preferred (Bayesian) tree topology suggests a sister group relationship between Spercheidae and Hydrophilidae, supporting the ‘hydrophilid lineage’; Epimetopidae are placed on the base of the ‘helophorid branch’, the monophyly of Sphaeridiinae is highly supported, nested deeply within Hydrophilidae closest to Enochrus, making Hydrophilinae and Acidocerini paraphyletic; Hydrobius appears as sister taxon to (Hydrochara + Hydrophilus) without a closer relationship to Acidocerini; the hydrophiloid–histeroid sister group relationship is confirmed. The topology of several taxa remains contradictory, and requires further investigations with a larger taxon sampling and additional molecular markers.     

Laboratory rearing of Hydrochus japonicus (Coleoptera: Hydrochidae) suggests larvae live at the water bottom

The aquatic larvae of the family Hydrochidae (Coleoptera) have been considered ‘mystery larvae’, because ecological knowledge about them is lacking. We discovered that Hydrochidae larvae (Hydrochus japonicus Sharp) are benthic via laboratory rearing. The larvae have a terminal spiracular atrium, but we did not observe them breathing at the water surface. The larvae fed on Naididae worms that were collected from the same habitat.     

中国条脊牙甲科昆虫及一新种记述

条脊牙甲科(Hydrochidae)仅两属,我国仅报道一属二种,即越南条脊牙甲Hydrochus annamita Regimbart和日本条脊牙甲Hydrochus japonicus Sharp。该文记述了一新种脊鞘条脊牙甲Hydrochus rhytipterus sp.nov. 和一新记录种瘤鞘条脊牙甲Hydrochus binodosus Motschulsky。