Diel activity patterns of Carabidae,Staphylinidae and Perimylopidae (Coleoptera) at South Georgia,Sub-Antarctic

Summary Six of the eight species of beetles at South Georgia, the southernmost beetles of the world, were investigated in outdoor arenas with pitfall traps for their diel patterns of locomotory activity. All of them were clearly nocturnal, the only exception being a small staphylinid which appeared to be active throughout the day and night. Activity of the other species was restricted to the dark period of the night, with little activity during twilight. Peak activity occurred before or at midnight. Activity was clearly correlated with temperature. Diurnal activity may involve a risk of overheating and desiccation, but could also have evolved in the past due to bird predation, which today is very low in the study area.     

Winter quarters of wetland ground beetles (Coleoptera,Carabidae) in South Scandinavia

Sites at various distances from eutrophic and mesotrophic lakes and fens on the island Öland in southern Sweden were systematically surveyed in summer (May–August) and autumn (late September–October) to elucidate the hibernation sites of wetland carabid beetles. Thirty-five of 47 wetland species were found in their winter quarters. In areas ≤50 m from the lakes and fens, the observed as well as the estimated number of hibernating wetland species was higher in mesic to dry sites than in wet or moist open sites. Very few overwintering beetles were detected far (≥120 m) from the water. There was no significant difference in the frequencies of macropterous and dimorphic (brachypterous) species and individuals hibernating close to, and more distantly from, water. Individuals of small species hibernated closer to water than larger ones. At least in Scandinavia, there is no convincing evidence that wetland species hibernate far away from water, migrating by flight. A considerable number of the species that were collected in their winter quarters are rare and red- listed in at least one of the Scandinavian countries. Winter quarters situated in mesic and dry meadows and woodland close to lakes and fens had the highest number of red-listed species. Therefore, it is of fundamental importance to protect such sites. Threats to the integrity of the current habitats are logging and various transformations of meadows, e.g. digging and removal of large objects such as stones. Cessation of grazing by cattle may also have a negative effect.     

An unexpected clade of South American ground beetles (Coleoptera,Carabidae, Bembidion)

Phylogenetic relationships of the Antiperyphanes Complex of the genus Bembidion are inferred using DNA sequences from seven genes (two nuclear ribosomal, four nuclear protein coding, and one mitochondrial protein coding). Redefined subgenera within the complex are each well-supported as monophyletic. Most striking was the discovery that a small set of morphologically and ecologically heterogeneous species formed a clade, here called subgenus Nothonepha. This unexpected result was corroborated by the discovery of deep pits in the lateral body wall (in the mesepisternum) of all Nothonepha, a trait unique within Bembidion. These pits are filled with a waxy substance in ethanol-preserved specimens. In one newly discovered species (Bembidion tetrapholeon sp. n., described here), these pits are so deep that their projections into the body cavity from the two sides touch each other internally. These structures in Bembidion (Nothonepha) are compared to very similar mesepisternal pits which have convergently evolved in two other groups of carabid beetles. The function of these thoracic pits is unknown. Most members of subgenus Nothonepha have in addition similar but smaller pits in the abdomen. A revised classification is proposed for the Antiperyphanes Complex.     

Phylogenetic diversification patterns and divergence times in ground beetles (Coleoptera: Carabidae: Harpalinae)

Background  

Harpalinae is a species rich clade of carabid beetles with many unusual morphological forms and ecological interactions. How this diversity evolved has been difficult to reconstruct, perhaps because harpalines underwent a rapid burst of diversification early in their evolutionary history. Here we investigate the tempo of evolution in harpalines using molecular divergence dating techniques and explore the rates of lineage accumulation in harpalines and their sister group.     

大步甲的分子系统与进化模式

大步甲主要分布于北半球,全世界大约有1000余种。因大步甲后翅退化,不能飞行,其移动能力和扩散范围都受到很大程度的限制,因此,容易产生地理隔离和遗传分化,从而成为研究物种分化和生物多样化的好材料。近年来,通过对大步甲分子系统的详细研究,不仅很大程度上解明了大步甲各分类群间的系统发育关系,而且对大步甲的系统演化过程和形态进化模式也有了较深的理解,获得了很多重要的见解。在此做一个简单的综述。     

Typology of life cycles of ground beetles (Coleoptera,Carabidae) in Western Palaearctic

An original classification of the life cycles of ground beetles from Western Palaearctic is proposed. The classification is based on a combination of five criteria: duration, number of generations per season, phenology of reproduction, stability, and repeatability of reproduction. According to the individual lifespan, the cycles are subdivided into annual and biennial ones. The annual life cycles may be uni-and bivoltine, whereas biennial ones are always univoltine. By the time of reproduction, winter-spring, spring, spring-summer, early summer, summer, late summer, summer-autumnal, autumnal, autumn-winter, winter, and aseasonal species are distinguished. The biennial and bivoltine cycles may be of both facultative and obligate nature. Species living only one season and having a continuous reproductive period are designated as semelparous, while those breeding during two or more years or having several distinct periods of reproduction in one season, as iteroparous. By now, 30 variants of life cycles in Carabidae from western Palaearctic have been established. Repeated similarly directed modifications of the life cycle may produce essentially different seasonal rhythms in some individuals. In this case, two subpopulation groups usually appear within the population. Under the most unfavorable conditions, these groups become practically isolated and hibernate at different ontogenetic stages. The individual development in each of these groups takes two years with the same seasonal rhythm. Among the types considered, only obligate-bivoltine life cycles are always polyvariant, but annual univoltine and obligate-biennial ones are always univariant. The facultative-bivoltine and biennial life cycles may be realized as uni-and polyvariant ones, depending on the environmental conditions.     

Ground beetles of the Ukraine (Coleoptera, Carabidae)

A review of the ground beetles of the Ukrainian fauna is given. Almost 750 species from 117 genera of Carabidae are known to occur in the Ukraine. Approximately 450 species of ground beetles are registered in the Carpathian region. No less than 300 species of ground beetles are found in the forest zone. Approximately 400 species of Carabidae present in the forest-steppe zone are relatively similar in species composition to those in the forest territories. Some 450 species of Carabidae are inhabitants of the steppe zone. Representatives of many other regions of heterogeneous biotopes such as forest, semi desert, intrazonal, etc. can be found in the steppe areas. The fauna of Carabidae (ca. 100 species) of the lowlands of southern Ukraine (sandy biotopes), situated mostly in the Kherson region, is very peculiar. The fauna of the Crimean mountains contains about 300 species. Conservation measures for the Carabidae are discussed.     

Diel activity patterns of some field Carabidae

Abstract. 1. A 24 h time-sorting pitfall trap was used to collect Carabidae in a field in north-east England in 1974, 1976 and 1977.
2. Harpalus rufipes comprised 62% of the 5288 adult Carabidae caught. It was nocturnal, with an activity peak after midnight. The male activity pattern lagged behind that of females by about 1 h. The activity peak shifted to earlier in the night during September.
3. Activity curves are given for eighteen other common species. Large species were all nocturnal, but a third of the smaller species were active in the day. The numbers caught of twenty-eight less common species are tabulated and show the same trend. Overall, nearly 60% of all species caught were nocturnal and 20% diurnal; the remainder did not show a distinct pattern of day or night activity.
4. A total of eighty-two larvae of H.rufipes, Nebria brevicollis and Notiophilus biguttatus were caught, and showed similar activity patterns to those of the respective adult beetles.     

Histological structure of tripartite mushroom bodies in ground beetles (Insecta, Coleoptera: Carabidae)

Contrary to members of the suborder Polyphaga, ground beetles have been found to possess tripartite mushroom bodies, which are poorly developed in members of basal taxa and maximally elaborated in evolutionarily advanced groups. Nevertheless, they do not reach the developmental stage, which has been previously found in particular families of beetles. It has been pointed out that a new formation of the Kenyon cells occurs during at least the first months of adult life, and inactive neuroblasts are found even in one-year-old beetles. It has been suggested that there is a relation between the Kenyon cell number and development of the centers of Kenyon cell new-formation.     

The thoracic morphology of cave-dwelling and free-living ground beetles from China (Coleoptera,Carabidae, Trechinae)

External and internal thoracic structures of two carabid species (Trechini) were examined and documented with different techniques. The study has a main focus on the eyeless cave-dwelling specialist Sinaphaenops wangorum, but detailed information is also provided for a species occurring in cave entrances. The phylogenetic background of the structural features of the thoracic skeletomuscular system was addressed. The thoracic morphology of the examined species was compared to conditions observed in previously studied carabids and non-related subterranean leiodids (Staphylinoidea) in order to identify cave adaptations. Main thoracic character complexes linked with cavernicolous habits in Trechini are elongation of the pro- and mesothorax and the legs, and a complete and irreversible reduction of the flight apparatus. The lost flight capacity is linked with a far reaching modification of skeletal elements of the metathorax including a strongly shortened and simplified metanotum, a shortened metaventrite, and completely reduced wings and sclerites of the wing base. The elongate prothorax together with the long and slender head and elongated legs distinctly increases the activity range in the subterranean lightless environment, which likely facilitates foraging of the carnivorous beetles. Some of the observed features like wing loss and elongation of the anterior thorax and legs are also found in some cave-dwelling Leiodidae (Leptodirini), whereas some other subterranean members of the staphylinoid family have a compact body and legs of normal length. In contrast to the predaceous Trechini, Leptodirini are scavengers.     

Restoration ecology meets carabidology: effects of floodplain restitution on ground beetles (Coleoptera,Carabidae)

The effects of different restoration activities on floodplain-inhabiting ground beetles were studied at a lowland river in northwestern Germany. In the 6-km² project area the bank reinforcement was stopped, the dikes that bordered the river on both sides were removed and two oxbows (disconnected parts of the main stream course) were reconnected to the river. We investigated the banks at two sites at the main river, at the two reconnected oxbows and at two unconnected oxbows as reference sites. To analyse the effects of the removal of the dikes we chose three floodplain sites in front and two reference sites behind the new dike. As a consequence of the lack of bank reinforcement and the reconnection of the oxbows, the area of open river banks, a rare bank structure at rivers in northwestern Germany, increased by a factor of 4.6 during the 4 years of investigation. Numerous stenotopic ground beetle species colonized the newly developed habitats at the main river and at the reconnected oxbows quickly, during several weeks or months, and established new populations as indicated by newly hatched individuals. The removal of the dikes should lead to a rewetting of the floodplain area that is incorporated in the flood dynamics, an important aspect of the development of typical floodplain habitats such as wet meadows, reeds and alluvial forests, while reference sites on the other side of the removed dike remained uninfluenced. Four years after the removal of the dikes no species turnover at the sites with a potentially changed water regime was recorded that indicated a shift of the carabid assemblages towards hygrophilous species. One reason could be the low frequency of inundations and their short duration during the investigation period. The flood dynamics could be sustained by the elevation and enlargement of the river bed, and periodic floods are the key factor for a development of floodplain habitats.     

The cephalic morphology of free-living and cave-dwelling species of trechine ground beetles from China (Coleoptera,Carabidae)

Morphological adaptations of cave-dwelling organisms including different groups of Coleoptera have fascinated researchers since a long time. Nevertheless, very few detailed documentations of the anatomy of cave beetles using modern techniques are available. In this study, we describe and illustrate external and internal cephalic features of free-living and cave-dwelling trechine carabid beetles using digital microscopy, SEM, micro-CT, and computer-based 3D reconstruction. Morphological characteristics found in three selected species with different habitat preferences are compared. The following derived features distinguish a troglobite species (Sinaphaenops wangorum Ueno et Ran 1998) from a species living in the entrance of caves (Trechiotes perroti Jeannel 1954) and from a fully epigean species (Bembidion sp.): (1) the optic lobes are completely missing; (2) the head capsule, mouth parts, and antennae are distinctly elongated; (3) some muscle attachment areas are shifted; and (4) an additional dilator of the pharynx is present. Despite of conspicuous differences likely related with subterranean habits, the link of some cephalic features to this specific habitat preference remains uncertain.     

Phylogeny and evolution of Digitulati ground beetles (Coleoptera, Carabidae) inferred from mitochondrial ND5 gene sequences

Genealogical trees have been constructed using mitochondrial ND5 gene sequences of 87 specimens consisting of 32 species which have been believed to belong to the division Digitulati (one of the lineages of the subtribe Carabina) of the world. There have been recognized six lineages, which are well separated from each other. Each lineage contains the following genus: (1) the lineage A: Ohomopterus from Japan; (2) the lineage B: Isiocarabus from eastern Eurasian Continent; (3) the lineage C: Carabus from China which are further subdivided into three sublineages; (4) the lineage D: Carabus from USA; (5) the lineage E: Carabus from the Eurasian Continent, Japan and North America; and (6) the lineage F: Eucarabus from the Eurasian Continent. Additionally, the genus Acrocarabus which had been treated as a constituent of the division Archicarabomorphi has been recognized to be the 7th lineage of the division Digitulati from the ND5 genealogical analysis as well as morphology. These lineages are assumed to have radiated within a short period and are largely linked to their geographic distribution.     

Dynamics of abundance of ground beetles (Coleoptera,Carabidae) in fenced areas in the Cis-Altai plain (Western Siberia)

The density of ground beetle populations was estimated by means of fenced pitfall traps in 2004–2008, in the environs of Biisk (Altai Territory) and Karasuk (Novosibirsk Province). In all, 64 species of ground beetles were revealed. The capture rates were usually higher in open than in fenced plots. No correlation was observed between the time of trap exposure and the captures. By the end of the 3rd–6th week of exposure, the fraction of juvenile and immature adults increased. The beetles captured within a fenced area 1 m² usually fell into the traps in 2–3 days. The maximal density of carabids in the fenced areas was estimated at 55–60 ind./m².     

The ground beetles (Coleoptera: Carabidae) of exposed riverine sediments in Scotland and northern England

A survey of invertebrates on exposed riverine sediments (ERS) in four catchments of rivers in Scotland and northern England was carried out in 1996 and 1997 using pitfall traps. The resulting 179 lists of ground beetle species were used in ordination and classification analyses to determine the different types of habitats and the environmental factors influencing species assemblage distribution. Types of ERS habitat differed between highland and lowland catchments; there were also different numbers of habitat types in each catchment. The distribution of ERS within catchments was related to geology, position in catchment, sediment composition and the amount of vegetation. Evidence of the positive nature of river engineering was identified and the role of river management is discussed. The numbers of nationally rare and scarce ground beetle species recorded from the ERS habitats in each catchment are reported and the factors affecting their distribution discussed.     

The Mecyclothorax beetles (Coleoptera,Carabidae, Moriomorphini) of Tahiti,Society Islands

The 101 species of Mecyclothorax Sharp known to inhabit Tahiti Island, French Polynesia are taxonomically revised, including 28 species that are newly described: Mecyclothorax claridgeiae sp. n., Mecyclothorax jeanyvesi sp. n., Mecyclothorax poria sp. n., Mecyclothorax aano sp. n., Mecyclothorax papau sp. n., Mecyclothorax manina sp. n., Mecyclothorax everardi sp. n., Mecyclothorax ramagei sp. n., Mecyclothorax pitohitiensis sp. n., Mecyclothorax curtisi sp. n., Mecyclothorax hoeahiti sp. n., Mecyclothorax ninamu sp. n., Mecyclothorax kokone sp. n., Mecyclothorax paahonu sp. n., Mecyclothorax kayballae sp. n., Mecyclothorax ehu sp. n., Mecyclothorax papuhiti sp. n., Mecyclothorax tuea sp. n., Mecyclothorax taatitore sp. n., Mecyclothorax konemata sp. n., Mecyclothorax arboricola sp. n., Mecyclothorax rahimata sp. n., M. oaoa sp. n., Mecyclothorax maninapopoti sp. n., Mecyclothorax hunapopoti sp. n., Mecyclothorax fefemata sp. n., Mecyclothorax maninamata sp. n., and Mecyclothorax niho sp. n. Mecyclothorax muriauxioides Perrault, 1984 is newly synonymized with Mecyclothorax muriauxi Perrault, 1978. Lectotypes are designated for: Thriscothorax altiusculus Britton, 1938; Thriscothorax bryobius Britton, 1938; Mecyclothorax globosus Britton, 1948: and Mecyclothorax sabulicola Britton, 1948. Dichotomous identification keys augmented by dorsal habitus and male aedeagal photographs are provided to the various species-groups and all included species. The spermatophore of Mecyclothorax papau sp. n. is described, with the ampulla and collar found to correspond dimensionally to the length of the internal sac flagellar plate. Variation among characters of the female reproductive tract is presented for all newly described plus other representative species comprising the radiation. Taxa are assigned to species groups, modified from the classification of G.G. Perrault, based on derived character states polarized using the Australian outgroup taxon Mecyclothorax punctipennis (MacLeay). Much of the species-level diversity on this small Pacific island is partitioned allopatrically over very small distributional ranges. No species is shared between Tahiti Nui and Tahiti Iti, and nearly all species in Tahiti Nui are geographically restricted to one ridgelike massif of that volcano. Cladistically similar species are often distributed on different massifs suggesting that vicariance associated with erosional valley formation has facilitated speciation, however several instances in which sister species occupy sympatric distributions on the same ridge system demonstrate that speciation may also occur across extremely localized landscapes. Such localized differentiation is facilitated by the low vagility of these small-bodied, flightless predators whose fragmented populations can persist and diverge within spatially limited habitat patches. The intense philopatry of Tahitian Mecyclothorax spp. coupled with the highly dissected landscape has produced the geographically densest adaptive radiation on Earth. This radiation has occurred very rapidly, with species durations averaging 300,000 yr; a speciation rate similar to that observed in Hawaiian Oliarus planthoppers and Laupala crickets, and East African Rift lake cichlid fishes.     

Testing abundance-range size relationships in European carabid beetles (Coleoptera, Carabidae)

Four of the eight hypotheses proposed in the literature for explaining the relationship between abundance and range size (the sampling artifact, phylogenetic non-independence, range position and resource breadth hypotheses) were tested by using atlas data for carabid beetles (Coleoptera, Carabidae) from Belgium, Denmark and the Netherlands. A positive relationship between abundance and partial range size was found in all three countries, and the variation in abundance was lower for widespread species. Analysis of the data did not support three of the proposed hypotheses, but did support the resource breadth hypothesis (species having broader environmental tolerances and being able to use a wider range or resources will have higher local densities and be more widely distributed than more specialised species). Examination of species' characteristics revealed that widespread species are generally large bodied, generalists (species with wide niche breadths occurring in a variety of habitat types) and are little influenced by human-altered landscapes, while species with restricted distributions are smaller bodied, specialists (species with small niche breadths occurring in only one or two habitat types), and favour natural habitat. Landscape alteration may be an important factor influencing carabid abundance and range size in these three countries with a long history of human-induced environmental changes.     

Chromosome evolution in ground beetles: localization of the rDNA loci in the tribe Harpalini (Coleoptera,Carabidae)

The pattern of localization of the ribosomal genes was studied by means of fluorescence in situ hybridization in 39 species of the tribe Harpalini. Most of them show one pair of autosomes carrying the ribosomal genes in a distal position of a single chromosome arm. This pattern is hypothesized to be ancestral for the whole tribe. Both, chromosome number and the number and localization of rDNA loci, show little variation and are therefore of little phylogenetic value. Only in the subtribe Ditomina is there enough variation to characterize phyletic relationships. The stability of rDNA loci is even higher than the constancy of chromosome number, as most species of Ditomina (genera Dixus, Eocarterus, Carterus, Odontocarus and Ditomus) have the usual pair of autosomes with rDNA loci, in spite of remarkable differences in the diploid number. Only Dixus sphaerocephalus and Dixus clypeatus have two autosomal pairs with a fluorescent signal. These results do not support the hypothesis that the high chromosome numbers found within Ditomina are the result of polyploid change from the ancestral 2n = 37 karyotype of the tribe Harpalini. Chromosomal translocations or the presence of mobile genetic elements are plausible sources of the few cases of intraspecific polymorphism in the rDNA loci found in species of Harpalus.