The systematic position of Meruidae (Coleoptera, Adephaga) and the phylogeny of the smaller aquatic adephagan beetle families

A phylogenetic analysis of Adephaga is presented. It is based on 148 morphological characters of adults and larvae and focussed on a placement of the recently described Meruidae, and the genus‐level phylogeny of the smaller aquatic families Gyrinidae, Haliplidae and Noteridae. We found a sister group relationship between Gyrinidae and the remaining adephagan families, as was found in previous studies using morphology. Haliplidae are either the sister group of Dytiscoidea or the sister group of a clade comprising Geadephaga and the dytiscoid families. Trachypachidae was placed as the sister group of the rhysodid‐carabid clade or of Dytiscoidea. The monophyly of Dytiscoidea including Meru is well supported. Autapomorphies are the extensive metathoracic intercoxal septum, the origin of the metafurca from this structure, the loss of Mm. furcacoxalis anterior and posterior, and possibly the presence of an elongated subcubital setal binding patch. Meruidae was placed as sister group of the Noteridae. Synapomorphies are the absence of the transverse ridge of the metaventrite, the fusion of abdominal segments III and IV, the shape of the strongly asymmetric parameres, and the enlargement of antennomeres 5, 7 and 9. The Meru‐noterid clade is the sister group of the remaining Dytiscoidea. The exact position of Aspidytes within this clade remains ambiguous: it is either the sister group of Amphizoidae or the sister group of a clade comprising this family and Hygrobiidae + Dytiscidae. The sister group relationship between Spanglerogyrinae and Gyrininae was strongly supported. The two included genera of Gyrinini form a clade, and Enhydrini are the sister group of a monophylum comprising the remaining Enhydrini and Orectochilini. A branching pattern (Peltodytes + (Brychius + Haliplus)) within Haliplidae was confirmed. Algophilus, Apteraliplus and the Haliplus‐subgenus Liaphlus form a clade. The generic status of the two former taxa is unjustified. The Phreatodytinae are the sister group of Noterinae, and Notomicrus (+ Speonoterus), Hydrocoptus, and Pronoterus branch off successively within this subfamily. The search for the larvae of Meru and a combined analysis of morphological and molecular data should have high priority. © The Willi Hennig Society 2006.     

Systematic placement of the recently discovered beetle family Meruidae (Coleoptera: Dytiscoidea) based on molecular data

The family Meruidae has been established recently for the newly discovered species Meru phyllisae Spangler & Steiner, 2005 from Southern Venezuela. These beetles are morphologically highly distinct and at a body length of 0.8 mm represent the perhaps smallest individuals of Adephaga. Here, we use DNA sequence data to place this enigmatic taxon relative to other aquatic groups in this suborder. Meruidae was most closely associated with Noteridae, supporting a previous analysis of morphological structures which had suggested this sister relationship, albeit with weak support. While different alignment strategies did not affect the topology, the precise placement of Meruidae was affected by the choice of tree reconstruction method. Bayesian inference suggests a sister relationship of Meruidae + Noteridae, while parsimony analyses retrieve Meruidae + Notomicrus (a basal noterid genus), which combined are the sister group of all remaining Noteridae. Considering morphological evidence, the former placement appears more plausible.     

First record of the family Hygrobiidae (Coleoptera: Adephaga) from Turkey

With the discovery of Hygrobia hermanni, the family Hygrobiidae is reported for the first time from Turkey. An illustration of the habitus and line drawings of diagnostic characters are provided.     

A genus-level supertree of Adephaga (Coleoptera)

A supertree for Adephaga was reconstructed based on 43 independent source trees – including cladograms based on Hennigian and numerical cladistic analyses of morphological and molecular data – and on a backbone taxonomy. To overcome problems associated with both the size of the group and the comparative paucity of available information, our analysis was made at the genus level (requiring synonymizing taxa at different levels across the trees) and used Safe Taxonomic Reduction to remove especially poorly known species. The final supertree contained 401 genera, making it the most comprehensive phylogenetic estimate yet published for the group. Interrelationships among the families are well resolved. Gyrinidae constitute the basal sister group, Haliplidae appear as the sister taxon of Geadephaga+Dytiscoidea, Noteridae are the sister group of the remaining Dytiscoidea, Amphizoidae and Aspidytidae are sister groups, and Hygrobiidae forms a clade with Dytiscidae. Resolution within the species-rich Dytiscidae is generally high, but some relations remain unclear. Trachypachidae are the sister group of Carabidae (including Rhysodidae), in contrast to a proposed sister-group relationship between Trachypachidae and Dytiscoidea. Carabidae are only monophyletic with the inclusion of a non-monophyletic Rhysodidae, but resolution within this megadiverse group is generally low. Non-monophyly of Rhysodidae is extremely unlikely from a morphological point of view, and this group remains the greatest enigma in adephagan systematics. Despite the insights gained, our findings highlight that a combined and coordinated effort of morphologists and molecular systematists is still required to expand the phylogenetic database to enable a solid and comprehensive reconstruction of adephagan phylogeny. See also Supplementary material in the online edition at doi:10.1016/j.ode.2006.05.003     

On the systematic position of the family Gyrinidae (Coleoptera: Adephaga)

Various characters of adult and larval members of Adephaga and Cupedidae were analyzed, and suggest that Gyrinidae are the sister-group of the remaining Adephaga, and are not closely related to the remaining aquatic Adephaga. The aquatic families Noteridae, Amphizoidae, Hygrobiidae and Dytiscidae seem to form a well founded monophyletic unit. The following characters are considered as synapomorphies of Adephaga excluding Gyrinidae: bifurcate condition of the muscle (= M.) tentoriopraementalis inferior, reduction of hypopharynx, strongly developed prosternal process, reduction in size and specialized modification of the ventral sclerite of the mesothorax, strongly developed mesofurcal arms, a high mesopleural ridge, globular mesocoxae restricted to rotatory movements, invaginated sternum VIII (coxostemum), the strongly curved base of the median lobe of the aedeagus, which articulates with the parameres, the rotated position of the aedeagus in repose, fusion of the larval clypeolabrum with the frons and reduction of the larval lacinia. Mesal shifting of M. episterno-coxalis prothoracis, and the fusion of the apical portions of the malpighian tubules of either side are considered as synapomorphies of Adephaga excluding Rhysodidae and Gyrinidae. Lateral reduction of the meta “sternal” transverse ridge and the presence of the subcubital setal binding patch of the hind wing are considered as synapomorphic characters of Trachypachidae, Noteridae, Amphizoidae, Hygrobiidae and Dytiscidae. We postulate that the metacoxal fusion occurred independently in gyrmids and the common ancestor of Trachypachidae, Noteridae, Amphizoidae, Hygrobiidae and Dytiscidae. Consequently we consider this character state as another synapomorphy of Trachypachidae and Hydradephaga excluding Haliplidae and Gyrinidae. The following characters are considered as synapomorphies of Noteridae, Amphizoidae, Hygrobiidae and Dytiscidae: Loss of tactile setae on the head capsule, metafurcal origin on the intercoxal wall, expansion of the intercoxal wall, elongation of the subcubital setal binding patch, loss of Mm. furca-coxale anterior and posterior, reduction of the larval abdominal segments IX and X, and the shifting of the uropmphi onto the ventral side of segment VIII. Presence of M. tentorio-mandibularis and M. stipitopalpalis intemus are certainly primitive features of adult gyrinids but the distribution of these character states among most members of Adephaga is yet unclear. Chemical defence gland constituents point towards a very isolated position of Gyrinidae. The old age of the group, documented by a larva found in upper Permian deposits, may support the hypothesis of a sister-group relation-ship between Gyrinidae and the remainder of Adephaga.     

Male achiasmatic meiosis in Caraboidea (Coleoptera,Adephaga)

The meiotic process was studied in fifty-three species belonging to the caraboid families Bembidiidae (48). Trechidae (3), Pogonidae (1), and Harpalidae (1). Males show achiasmatic meiosis patterns of the Callimantis type. In females only early prophase stages were observed, that are similar to those of the males. The characteristics of this abnormal meiosis and its evolutionary and cytotaxonomic significance are discussed.     

A new intertidal beetle (Coleoptera: Limnichidae) from the Great Barrier Reef

A new genus is erected for a minute beetle found in the intertidal zone on Heron Island, the adult and larva of which are described. The relationships of the genus are discussed, and it is placed in the family Limnichidae as the sole representative of a new subfamily.     

细花萤科分类概述与中国种类名录（鞘翅目：郭公总科）

介绍了细花萤科的识别特征,总结了该科分类历史,提供了属级检索表,编制了中国已知种类名录。基于标本检视信息,对一些物种地理分布地进行了补充,包括 Lobonyx guerryi (Pic, 1920)、Prionocerus bicolor Redtenbacher, 1868、P. coeruleipennis Perty,1831、Idgia deusta Fairmaire,1878和I. flavirostris Pascoe,1860。     

A new coptoclavid larva (Coleoptera: Adephaga: Dytiscoidea) from the Middle Jurassic of China,and its phylogenetic implication

Daohugounectes primitivus, a new genus and species of coptoclavid beetles, is described from 67 fossil larvae from the Jurassic locality of Daohugou, northeastern China. It differs from other coptoclavids in the combination of the following characters: lateral lobes of nasale present; legs relatively short, with tarsi flat and slightly dilated; abdominal tergite VIII almost circular; derivative of abdominal segment IX present; urogomphi short; and helical thickening of tracheae weak. Most of these features are plesiomorphic for the family Coptoclavidae and the superfamily Dytiscoidea. Among dytiscoids, a derivative of abdominal segment IX is present only in the larvae of the recently discovered relic family Aspidytidae.     

Discovery of Aspidytidae,a new family of aquatic Coleoptera

The six extant aquatic families of Hydradephaga (Coleoptera) known so far represent a diverse group of beetles morphologically highly modified for life in the water. We report the discovery of a new genus with two species from South Africa and China, which differ greatly from all extant families, but resemble the Jurassic-Cretaceous dagger Liadytidae (the dagger symbol indicates that the taxa are known only as fossils). Based on a combined phylogenetic analysis of molecular and morphological data we erect a new family, Aspidytidae, which is the sister group of Dytiscidae plus Hygrobiidae. We propose a new scenario for the evolution of swimming behaviour in adephagan beetles, in which the transition into the aquatic environment is followed by complex and repeated changes in lifestyles, including the secondary complete loss of swimming ability in Aspidytidae.     

A new insect cell line from the longicorn beetle Plagionotus christophi (Coleoptera: Cerambycidae)

We have established a continuous cell line from the fat body tissue of the longicorn beetle Plagionotus christophi. The cells have been serially subcultured in MGM450 medium, and the line has been designated as PC-1. The cells were grown in suspension and comprise largely flattened spindle- or oval-shaped cells morphologically related to blood cells of longicorn beetles. The chromosome number ranged from 19 to 36, with a mode of 20 (diploid). The growth curve was determined at the 100th passage, and the population doubling time was calculated to be 3.79 d. Isozyme analysis of malic enzyme, phosphoglucose isomerase, and phosphoglucomutase revealed that PC-1 cells were enzymatically distinct from coleopteran XP-1, AnCu-35, dipteran AeAl-2, and lepidopteran GaMe-LF1 cell lines.     

A new Ophiostoma species isolated from the ambrosia beetle Xyleborus dryographus (Coleoptera: Scolytidae)

An undescribed ophiostomatoid fungus was isolated from the scolytid beetle Xyleborus dryographus in south-west Germany. The fungus is described as Ophiostoma verrucosum sp. nov. with a Hyalorhinocladiella anamorph. The teleomorph is characterized by thick-sheathed ascospores, numerous divergent ostiolar hyphae and an ornamented perithecial base.     

Eucamaragnathus desenderi, a new ground beetle species from Africa (Coleoptera, Carabidae)

Eucamaragnathus desenderisp. n., a new ground beetle species of the tribe Hiletini, is described from eastern and southern Africa and dedicated to the recently deceased Belgian carabidologist Konjev Desender. The new taxon is known so far from localities in Zambia (Mukuku, southeast of Mansa) and in South Africa (Bothaville, south of Klerksdorp). The new species belongs to the Eucamaragnathus castelnaui group and is characterized by shape of pronotum, smooth or sparsely punctate pronotal transverse impression, characters of male genitalia and elytral striae continued to the apex. Illustrations of the habitus, the median lobe and its internal sac and several other morphological features are presented. An updated identification key to the African Eucamaragnathus species is given.     

The morphological evolution of the Adephaga (Coleoptera)

The evolution of the coleopteran suborder Adephaga is discussed based on a robust phylogenetic background. Analyses of morphological characters yield results nearly identical to recent molecular phylogenies, with the highly specialized Gyrinidae placed as sister to the remaining families, which form two large, reciprocally monophyletic subunits, the aquatic Haliplidae + Dytiscoidea (Meruidae, Noteridae, Aspidytidae, Amphizoidae, Hygrobiidae, Dytiscidae) on one hand, and the terrestrial Geadephaga (Trachypachidae + Carabidae) on the other. The ancestral habitat of Adephaga, either terrestrial or aquatic, remains ambiguous. The former option would imply two or three independent invasions of aquatic habitats, with very different structural adaptations in larvae of Gyrinidae, Haliplidae and Dytiscoidea.     

A new species of tiger beetle from southeastern Arizona and Mexico (Coleoptera,Carabidae, Cicindelini)

A new tiger beetle species, Cicindelidia melissa Duran & Roman, sp. n., of the tribe Cicindelini, is described from high elevation montane forests of southeastern Arizona and Mexico. It appears to be most closely related to Cicindelidia nebuligera (Bates) but is distinguished on the basis of multiple morphological characters and geographic range. The new species is also superficially similar to the widespread Cicindelidia sedecimpunctata (Klug), but distinguished on the basis of multiple morphological characters and habitat. Habitus, male and female reproductive structures, and known distribution map are presented.     

A chromosome study of Spanish Bembidiidae and other Caraboidea (Coleoptera,Adephaga)

The karyotypes were studied of fifty-three Spanish Caraboidea species belonging to the following families: Trechidae (3 species), Bembidiidae (48), Pogonidae (1) and Harpalidae (1). Differences in the shape of the largest pair of autosomes (A pair) and the Y-chromosome are frequent among closely related species. The chromosomes of these species have a peculiar centromeric region weakly constricted and surrounded by conspicuous heterochromatic blocks. Eight species have a heteromorphic A pair, probably due to differences in the length of the nucleolar organizer. Species of the first three families either have a male karyotype of 24 chromosomes, or one derived from it, while the only species of the fourth family has a male karyotype of 39 chromosomes derived from the basic karyotype of the Harpalidae, 2n=37.     

A new genus and species of timber beetle (Coleoptera: Lymexylidae) from the Baltic amber

Ponomarenkylon alexandri gen. et sp. nov. (Melittommatinae) from the Late Eocene Baltic amber is described. The long filiform antennae and the apparent absence of sensillary organs, which are frequently present on modified maxillary palps in other lymexylids, are evidence of the primitive state of the new genus.