Si-Qin Ge

On the head morphology of Tetraphalerus, the phylogeny of Archostemata and the basal branching events in Coleoptera

Internal and external features of Tetraphalerus bruchi were studied using X‐ray microtomography (µ‐CT) and other techniques, and head structures were described in detail. µ‐Ct is highly efficient for the assessment of anatomical data. A data matrix with 90 morphological characters of recent and fossil beetles was analyzed with different approaches (parsimony, Bayesian analysis). The results of the parsimony analysis resulted in the following branching pattern: (†Tshekardocoleidae + (†Permocupedidae, †Rhombocoleidae + (†Triadocupedidae + ((Adephaga + (Myxophaga + Polyphaga))) + Archostemata s.str. [including Jurodidae]))). Sikhotealinia is placed as sister group of †Jurodes (Jurodidae), and Jurodidae as sister group of the remaining Archostemata (Bayesian analysis) or of a clade comprising Micromalthidae, Crowsoniellidae, †Ademosynidae, †Schizophoridae and †Catiniidae. The monophyly of Ommatidae and Cupedidae is well supported and Priacma is placed as the sister group of all other Cupedidae. Important events in the early evolution of Coleoptera are the shortening of the elytra and the transformation of the elytral venation (Coleoptera excluding †Tshekardocoleidae), the formation of a closed subelytral space (Coleoptera excluding †Tshekardocoleidae and †Permocupedidae), the reduction of two apical antennomeres, and the loss of the broad prothoracic postcoxal bridge (Coleoptera excluding †Tshekardocoleidae, †Permocupedidae and †Rhombocoleidae). Plesiomorphic features preserved in extant Archostemata are the tuberculate cuticle, the elytral pattern with parallel longitudinal ribs and window punctures, a mesoventrite with a transverse ridge, triangular mesocoxae with a distinct meron, and the exposed metatrochantin. The fossils included in the analyses do not only contribute to the reconstruction of character evolution but also influence the branching pattern. An understanding of the major evolutionary events in Coleoptera would not be possible without considering the rich fossil record of Permian and Mesozoic beetles.

The thorax of Mantophasmatodea, the morphology of flightlessness, and the evolution of the neopteran insects

Mantophasmatodea was described as a new insect order in 2002. Since then, this small group of wingless insects has developed into one of the best investigated insect taxa. Nevertheless, many aspects of mantophasmatodean morphology as well as their evolutionary relationships remain ambiguous. To determine the phylogenetic relationships of Mantophasmatodea based on an extended character set and to elucidate possible morphological adaptions towards flightlessness, we investigated the thoracic morphology of two species, Austrophasma caledonensis and Mantophasma sp. The morphological similarity between these two species is striking and no differences in musculature were found. The mantophasmatodean thorax strongly resembles that of ice crawlers (Grylloblattodea), especially with respect to the presence of pleural processes in the meso‐ and metathorax, branched furcae in all segments, and similar muscle equipment. In a cladistic analysis containing all major lineages of Neoptera, the monophyly of Polyneoptera is supported by the presence of an anal fan and several modifications of the wing joint. Within Polyneoptera, a sister‐group relationship between stoneflies and the remaining Polyneoptera is supported. A clade comprising Mantophasmatodea and the Grylloblattodea gains strong support from thoracic morphology and can be considered assured. Potential thoracic apomorphies include prothoracic paracoxal invaginations, pterothoracic pleural arms that originate from the epimeron, and a unique metathoracic sterno‐coxal musculature. The monophyly of Orthoptera and Dictyoptera is further supported while the deeper polyneopteran nodes remain unresolved. Among the wingless taxa investigated we found few general morphological adaptations whereas, in other aspects, especially in the musculature, strong differences could be observed. However, much more research on the strongly neglected topic of flightlessness is required to make reliable statements.

On the phylogeny and evolution of Mesozoic and extant lineages of Adephaga (Coleoptera, Insecta)

The relationships of extant and extinct lineages of Adephaga were analysed formally for the first time. Emphasis is placed on the aquatic and semiaquatic groups and their evolution in the Mesozoic. †Triadogyrus and †Mesodineutus belong to Gyrinidae, the sister group of the remaining families. †Triaplidae are the sister group of the following groups (Haliplidae, Geadephaga, Dytiscoidea incl. †Liadytidae, †Parahygrobiidae and †Coptoclavidae [major part]). The lack of a ventral procoxal joint and a very short prosternal process are plesiomorphies of †Triaplidae. †Coptoclavidae and †Timarchopsinae are paraphyletic. †Timarchopsis is placed in a geadephagan clade. In contrast to other coptoclavids, its metathorax is close to the condition found in Haliplidae, with a complete transverse ridge and coxae with large plates and free mesal walls. †Coptoclavidae s.str., i.e. excl. †Timarchopsis, is a dytiscoid subgroup. The mesal metacoxal walls are fused, the coxal plates are reduced, and the transverse ridge is absent. †Stygeonectes belongs to this dytiscoid coptoclavid unit and is therefore misplaced in †Timarchopsinae. †Liadytidae belongs to a dytiscoid subgroup, which also comprises the extant families Aspidytidae, Amphizoidae, Hygrobiidae and Dytiscidae. †Parahygrobia is the sister group of Hygrobiidae. The larvae are characterized by a broad gula, the absence of the lacinia, retractile maxillary bases and very long urogomphi set with long setae. †Liadytiscinae is the sister group of extant Dytiscidae. There is no support for a clade †Eodromeinae and for Trachypachidae incl. †Eodromeinae. †Fortiseode is nested within Carabidae. The exclusion of fossil taxa has no effect on the branching pattern. The evolution of Adephaga in the Mesozoic is discussed. Possible reasons for the extinction of †Coptoclavidae are the rise of teleost fish and the competition of Gyrinidae and Dytiscidae, which possess efficient defensive glands and larval mandibular sucking channels.

Thoracic morphology of adults of Derodontidae and Nosodendridae and its phylogenetic implications (Coleoptera)

Abstract External and internal structures of the thorax of six adult representatives of the families Derodontidae and Nosodendridae were examined. A detailed description of the skeleton and musculature is presented for Derodontus maculatus and Nosodendron sp. Phylogenetically relevant characters are discussed and analysed cladistically. A basal origin of Derodontidae within Polyphaga and a sister‐group relationship between this suborder and the remaining Coleoptera are not supported. Muscular and skeletal features of Derodontidae are largely consistent with the typical polyphagan pattern and the group is characterized by many specialized features. Previous references to the family as ‘primitive’ are unjustified. The absence of a firm connection between the meso‐ and metaventrite is a secondary feature, as seen in Scirtoidea and some members of Leiodidae. The contact of the metanepisternum with the mesocoxal cavity is probably also an autapomorphic condition. Two derived muscular features are shared by Derodontidae and Nosodendridae, and several muscle losses are shared by these two families and Scirtoidea and Dascillidae. The monophyly of Derodontidae and a sister‐group relationship between Peltastica and the remaining genera are confirmed. Laricobius and Nothoderodontus are probably sister groups. Nosodendron is characterized by several autapomorphic features. Whether the flight musculature is reduced in all members of Nosodendridae is unclear.

Is Meru a specialized noterid (Coleoptera, Adephaga)?

Larval characters of Meru were extracted from the recently published description and added to an extensive data matrix from an earlier study on the phylogenetic position of the genus and family. The results confirm the earlier postulated clade Meruidae + Noteridae with strong support. The larvae share several characteristics with noterid larvae, notably the specific head shape, with the greatest width close to the foramen occipitale, the fissure‐shaped posterior tentorial grooves at the posterior margin of the head capsule and the anteriorly cleft prementum. From a formal point of view, it would be justified to treat Meru as a subgroup of Noteridae (if the larva is properly identified). We refute the placement of Meruidae as a sister group of the remaining Dytiscoidea (including Noteridae). The new larval characters are valuable and informative, but a small set of external features is not sufficient for a reliable placement of Meruidae.

Moss-inhabiting flea beetles (Coleoptera: Chrysomelidae: Galerucinae: Alticini) with description of a new genus from Cangshan, China

The world diversity of moss cushion-inhabiting and moss-feeding flea beetles is documented and discussed. A new genus (Cangshanaltica) with a single new species (Cangshanaltica nigra sp. nov.) from Yunnan Province in China is described and illustrated. It is similar to Benedictus Scherer, Ivalia Jacoby, Minota Weise, Paraminota Scherer, and Phaelota Jacoby. An identification key for all flea beetle genera known to occur in mosses in the eastern hemisphere is provided. http://www.zoobank.org/urn:lsid:zoobank.org:pub:6341724E-BA3F-4979-B226-108D0CA64B92

The first complete 3D reconstruction of a Spanish fly primary larva (Lytta vesicatoria, Meloidae, Coleoptera).

The first detailed anatomical study of a primary larva of Meloidae is presented. Thereby techniques such as three-dimensional reconstructions, microtome sections, SEM (scanning electronic microscopy) and CLSM (confocal laser scanning microscopy) are applied. The structural features are discussed in the context of phylogeny, but also possible correlations with parasitism, phoresy and miniaturisation. The triungulin first instar larva is likely an apomorphy of Meloidae excl. Eleticinae and linked with a specialisation on acridoid eggs or larvae and provisions of bees. The campodeid body shape of Lytta and Meloinae is a groundplan feature of Meloidae, whereas a navicular body is an autapomorphy of the generally phoretic larvae of Nemognathinae. Head structures of Lytta and features of the postcephalic body are largely plesiomorphic. The musculature of the head is only moderately simplified while the one of the postcephalic body is well developed. Its thorax is largely characterised by plesiomorphies. The characteristics of the legs suggest phoretic habits, even though this does not apply to larvae of Lytta. It is conceivable that a phoretic behaviour is secondarily lost, together with some but not all morphological modifications related to it. Derived features of the abdomen of Meloidae are the complete loss of the fixed urogomphi (also missing in Rhipiphoridae and other related groups) and the presence of one or two conspicuous caudal bristles. Only few features of Lytta are shared with the parasitic larvae of Rhipiphoridae and Strepsiptera. These characteristics, which are possibly linked with specialised life habits, have obviously evolved independently. Miniaturisation effects are minimal in the larvae of Lytta.

Revision of the chrysomeline genera Potaninia, Suinzona and Taipinus (Coleoptera) from eastern Asia, with a biogeographic scenario for the Hengduan mountain region in south‐western China

The eastern Asian leaf beetle genera Potaninia Weise, Taipinus Lopatin and Suinzona Chen (Entomoscelina) are revised. A cladistic analysis, a key to the species, a generic redescription, descriptions of new species and distributional records are provided. The analysis of 44 exoskeletal and genitalic characters and one character of the altitudinal distribution suggests a clade comprising all three genera, a clade including Suinzona and Taipinus, the monophyly of the latter genus and a clade comprising 20 species of Suinzona occurring in high altitudes in the Hengduan Mountain region. The three species of Suinzona occurring at lower altitudes (S. yunnana, S. laboissierei and S. monticola) are isolated from this successful lineage. The strict consensus tree of the initial analysis is not well resolved, but only one tree was obtained after applying the successive reweighting option (in paup). This analysis suggests that Taipinus may be nested within Suinzona, which would imply paraphyly of the latter genus as it is presently defined. Nevertheless, considering the results of the initial analysis and the apparent instability of the phylogenetic results based on morphological data alone, we decided to maintain the generic rank of Taipinus at this stage. Eighteen new species from China are described and illustrated: Suinzona bergealisp.n., Suinzona bienkowskii sp.n., Suinzona chenisp.n., Suinzona cuiaesp.n.,Suinzona faldermannisp.n., Suinzona geblerisp.n., Suinzona jacobsonisp.n., Suinzona konstantinovisp.n., Suinzona lopatinisp.n., Suinzona medvedevisp.n., Suinzona menetriesisp.n., Suinzona mikhailovisp.n., Suinzona motschulskyisp.n., Suinzona ogloblinisp.n., Suinzona pallasisp.n., Taipinus convexussp.n., Taipinus elatussp.n. and Taipinus globosussp.n. Six described species are transferred from Oreomela Jacobson to Suinzona Chen: Suinzona belousovi (Lopatin) comb.n., Suinzona potanini (Lopatin) comb.n., Suinzona parva (Lopatin) comb.n., Suinzona wangi (Lopatin) comb.n., Suinzona yangi (Lopatin) comb.n. and Suinzona yunnana (Lopatin) comb.n. A biogeographic scenario for the genera is discussed. Whereas S. yunnana, S. laboissierei, S. monticola and the species of Taipinus are restricted to relatively low mountains, a major radiation of a clade within Suinzona took place in the Hengduan Mountain region above 3300 m a.s.l., which is presently the centre of diversity of the genus. These species are flightless and show a preference for scree slopes and rock crevices.

Geometric morphometrics analysis of the hind wing of leaf beetles: proximal and distal parts are separate modules

Abstract The success of beetles is mainly attributed to the possibility to hide the hindwings under the sclerotised elytra. The acquisition of the transverse folding function of the hind wing is an important event in the evolutionary history of beetles. In this study, the morphological and functional variances in the hind wings of 94 leaf beetle species (Coleoptera: Chrysomelinae) is explored using geometric morphometrics based on 36 landmarks. Principal component analysis and Canonical variate analysis indicate that changes of apical area, anal area, and middle area are three useful phylogenetic features at a subtribe level of leaf beetles. Variances of the apical area are the most obvious, which strongly influence the entire venation variance. Partial least squares analysis indicates that the proximal and distal parts of hind wings are weakly associated. Modularity tests confirm that the proximal and distal compartments of hind wings are separate modules. It is deduced that for leaf beetles, or even other beetles, the hind wing possibly exhibits significant functional divergences that occurred during the evolution of transverse folding that resulted in the proximal and distal compartments of hind wings evolving into separate functional modules.

Is Crowsoniella relicta really a cucujiform beetle

Crowsoniella relicta Pace, one of the most obscure and cryptic beetle taxa, was recently transferred from Archostemata to the polyphagan series Cucujiformia. We discuss the arguments in favour of this hypothesis. The placement of the species is evaluated with a cladistic approach and two different morphological data sets: one aiming mainly to clarify the relationships of extinct and extant archostematans, and one aimed at resolving species‐level phylogeny for the suborder. The results suggest clearly that a position of Crowsoniella within a polyphagan subgroup is very unlikely, and that a placement in Archostemata is justified and should be maintained. Due to the serious lack of anatomical information, non‐destructive µ‐CT scanning of enigmatic taxa like Crowsoniella Pace and Sikhotealinia Lafer should have high priority.