Antennal sensilla of the ground beetle Bembidion lampros Hbst (Coleoptera, Carabidae)

Antennal sensilla typology, number and distribution pattern were studied in the ground beetle Bembidion lampros Hbst (Coleoptera, Carabidae) using scanning electron microscopy. The 1.6–1.8 mm long filiform antennae of both sexes consist of the scape, pedicel and of the flagellum composed of nine flagellomeres. In both sexes, three types of sensilla chaetica, two types of sensilla trichodea, five types of sensilla basiconica, one type of sensilla coeloconica, one type of sensilla campaniformia and Böhm sensilla were distinguished. The possible function of the sensilla was discussed and three types of sensilla were considered as olfactory, sensilla trichodea type 2 and sensilla basiconica types 1 and 2. Olfactory sensilla occupy dorsal and/or ventral areas of the flagellomeres and occur sparsely (sensilla basiconica type 1) or not at all (sensilla basiconica type 2 and sensilla trichodea type 2) outside these areas. No remarkable sexual differences in the types, numbers and distribution of antennal sensilla were found.     

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.     

Wild flower seed predation by Pterostichus madidus (Carabidae: Coleoptera)

The objective of the study was to investigate the ability of Pterostichus madidus, one of the most abundant carabid beetles in the United Kingdom, to consume wildflower seeds. The plant species chosen are commonly included in wildflower seed mixes sown to enhance the biodiversity of arable field margins, and hence any seed predation could potentially reduce successful seedling establishment. The study combined cafeteria style laboratory feeding experiments with predation studies in an established field margin. In laboratory studies the Pterostichus madidus consumed both unimbibed and imbibed seeds of Centaurea scabiosa, Galium verum, Leucanthemum vulgare and Primula veris. Seed consumption was still evident when Drosophila pupae were also supplied, although there was significant preference for the pupae. Placement of seeds in the field showed high levels of seed consumption, although part of this was attributed to slugs. Carabid beetles may have a significant role as wild flower seed predators and thus may affect establishment of re‐seeded flower‐rich meadows.     

Larval and adult seed consumption affected by the degree of food specialization in Amara (Coleoptera: Carabidae)

Many carabid beetles (Coleoptera: Carabidae) are known to feed on plant seeds, but the level of specialization on this food differs. This is the first study in which seed consumption is assessed for all larval instars and adults of ground beetles. Three species of Amara with syntopic occurrence, Amara aenea (DeGeer), Amara familiaris (Duftschmid) and Amara similata (Gyllenhal), were examined. Larvae of all three instars and adults were fed seeds of Stellaria media (L.) Vill., Capsella bursa‐pastoris (L.) Med. and Taraxacum officinale Wick. ex Wigg. in a laboratory no‐choice experiment. In general, larvae, particularly the first instar, showed greater differences in seed consumption than the adults, although the latter showed similar but less marked pattern. Amara aenea consumed all offered seed diets in all life stages. All three larval instars of granivorous A. familiaris almost exclusively fed on seeds of S. media and the adults also ate significantly more of this than other seeds. Amara similata consumed mostly seeds of C. bursa‐pastoris in the first instar and adult stages, whereas the larvae of the later instars seemed to be unspecialized on particular seed diet. Differences in seed‐specific consumption between larval instars in granivorous carabids are reported for the first time. The results provide further support for the parallel evolution of various degrees of granivory in the genus Amara, which may ultimately facilitate species coexistence. The daily seed consumption by the larvae was comparable or (in case of the third instar) even higher than that by the adults. Hence, we suggest that larvae may be the important consumers of seed in the field and should not be forgotten when seed predation is assessed.     

The evolution and age of populations of Scaphinotus petersi Roeschke on Arizona Sky Islands (Coleoptera, Carabidae, Cychrini)

Populations of the ground beetle Scaphinotus petersi are isolated in subalpine conifer forest habitats on mountain ranges or Sky Islands in southeastern Arizona. Previous work on this species has suggested these populations have been isolated since the last post-glacial maximum times as warming caused this cool adapted species to retreat to high elevations. To test this hypothesis, we inferred the phylogeny from mitochondrial DNA sequence data from several Arizona Sky Island populations of Scaphinotus petersi and estimated the divergence time of the currently isolated populations. We found two major clades of Scaphinotus petersi, an eastern clade and a western group. Our results indicated most mountain ranges form clades except the Huachucas, which are polyphyletic and the Santa Catalinas, which are paraphyletic. We estimated the Pinaleño population is much older than the last glacial maximum, but the Huachuca and Pinal populations may have been fragmented from the Santa Catalina population since the post-glacial maximum times.     

Sensilla on maxillary and labial palps in a helicophagous ground beetle larva (Coleoptera,Carabidae)

Sensilla on the labial and maxillary palp of Carabus lefebvrei Dejean, 1826 larvae were investigated using scanning and transmission electron microscopy. Two identical sets of sensilla were present on the tips of both palp pairs, and four morphological types of sensilla were identified: sensilla basiconica types 1 and 2, sensilla coeloconica and sensilla digitiformia. Ultrastructure indicates that the sensilla basiconica type 1 and coeloconica have a chemical role as gustatory and olfactory receptors, respectively, while sensilla basiconica type 2 are mechanoreceptors and the sensilla digitiformia are probably thermo‐ and hygroreceptors. Their function is discussed in relation to specialized prey detection and habitat adaptations.     

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.     

Absence asymmetry: the evolution of monorchid beetles (Insecta: Coleoptera: Carabidae)

Asymmetrical monorchy, or the complete absence of one testis coupled with the presence of its bilateral counterpart, is reported for 174 species of the carabid beetle tribes Abacetini, Harpalini, and Platynini (Insecta: Coleoptera: Carabidae) based on a survey of over 820 species from throughout the family. This condition was not found in examined individuals of any other carabid beetle tribes, or of other adephagan beetle families. One monorchid taxon within Platynini exhibits symmetrical vasa deferentia at the beginning of the pupal stadium, suggesting that developmental arrest of the underdeveloped vas deferens takes place in pupation. The point at which development of the testis is interrupted is unknown. Complete absence of one organ of a bilateral pair--absence asymmetry--is rarely found in any animal clade and among insects is otherwise only known for testes in the minute-sized beetles of the family Ptiliidae, ovaries in Scarabaeinae dung beetles, and ovaries of some aphids. Based on current phylogenetic hypotheses for Carabidae, testis loss has occurred independently at least three times, and up to five origins are possible, given the variation within Abacetini. Clear phylogenetic evidence for multiple independent origins suggests an adaptive or functional cause for this asymmetry. A previously posited taxon-specific hypothesis wherein herbivory in the tribe Harpalini led to testis loss is rejected. Optimal visceral packing of the beetle abdomen is suggested as a general explanation. Specifically, based on the function of various organ systems, we hypothesize that interaction of internal organs and pressure to optimize organ size and space usage in each system led to the multiple origins and maintenance of the monorchid condition. Testes are the only redundant and symmetrically paired structures not thought to be developmentally linked to other symmetrical structures in the abdomen. Among all possible organs, they are the most likely--although the observed frequency is very small--to bypass constraints that maintain bilateral symmetry, resulting in absence asymmetry. However, based solely on our observations of gross morphology of internal organs, no function conclusively explains the ontogenetic loss of one testis in these taxa. Unlike the analogous absence asymmetry of organs in other animal groups, no dramatic body-form constraint--e.g., snakes and lung loss, ptiliid beetles' small body-size and relatively giant sperm--or adaptive scenario of improved locomotory performance--e.g., birds and ovary loss due to flight constraints-applies to these carabid beetles. We tentatively suggest that testis loss is driven wholly by an interaction among the internal organs of these beetles, possibly due to selective pressure to maximize the comparatively large accessory glands found in these taxa. However, as the ordering of these evolutionary events of testis loss and accessory gland size increase is not known, large accessory glands might have secondarily evolved to compensate for a decreased testicular output.     

The importance of streamside sandbars to ground beetle (Coleoptera, Carabidae) communities in a deciduous forest

We used pitfall traps to sample ground beetles on sandbars along a small woodland stream and in the adjacent floodplain forest (Oglethorpe Co., GA, USA). We captured a total of 1,477 ground beetles representing 41 species. Twenty-two species were exclusive to sandbars, while eight were found only in the forested habitat. Ground beetles were captured in significantly greater numbers from sandbars, especially Brachinus janthinipennis and Omophron americanum. The B. janthinipennis record represents a new state record for the species. This study demonstrates that many unique species can be found in specialized microhabitats and emphasizes the need for biodiversity assessment surveys to include a wide range of these microhabitats within a survey area. In addition, it appears that many generalist forest species might use sandbars seasonally to exploit available resources. The U.S. Government's right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged.     

Carabid beetle (Coleoptera: Carabidae) richness and functional traits in relation to differently managed grasslands in the Alps

Species richness, composition, and functional traits of carabid beetle assemblages (Coleoptera: Carabidae) were studied in relation to different grassland management. Carabid beetles were sampled during the summers 2008 and 2009 by 165 traps located in 11 sites in the central-eastern Italian Alps. Using mixed effect models to account for potential spatial bias, we found that mown grasslands had significantly more species, a lower proportion of wingless species and a lower proportion of species with long larval development than grazed and natural grasslands. Within grazed and mown grasslands, neither cattle density nor number of cuts had any significant effect neither on species richness nor on any of the traits. The influence of grassland management can be summarised as follows: (1) grazing does not change community structure and functional traits compared to natural grasslands; (2) mowing negatively affects the carabid beetle assemblages; (3) the intensity of grazing and of cutting may not affect the structure of species assemblages of ground beetles. Our results support the hypothesis that agroecosystem practices in alpine grasslands influence carabid beetle communities. Specifically, the species with traits typical of undisturbed habitats (low dispersal abilities and long larval development) are more sensitive to perturbations (e.g. cutting). Our suggestion for agricultural and environmental planning and for conservation schemes is that the preservation of natural grasslands (e.g. forest gaps) and the implementation of grazing should be promoted during the planning of agroecosystem mosaics.     

Rediscovery of Bembidion (Lymnaeum) nigropiceum (Marsham) (= puritanum Hayward) in Massachusetts, with remarks on biology and habitat (Coleoptera, Carabidae, Bembidiini)

Bembidion (Lymnaeum) nigropiceum (Marsham) (=puritanum Hayward), a European species introduced into Massachusetts but presumed not to have become established, has been rediscovered during the Boston Harbor Islands All Taxa Biodiversity Inventory undertaken by the Museum of Comparative Zoology and the National Park Service. A summary is presented of treatment of this species in North America. Data on specimens collected are presented, along with observations on habitat and biology. Some speculations are presented about its highly specialized habitat in the gravel pushed up by high tide, which may act as a food-trapping sieve. A few words are included about future actions needed to resolve questions of distribution and behavior.     

Taxonomic review of the Pterostichini and Loxandrini fauna of New Caledonia (Coleoptera, Carabidae)

The generic-level taxa included in Pterostichini and Loxandrini from New Caledonia are reviewed and a key to genera and species provided. Two new genera are described, Paniestichus and Abacophrastus, with the following new species: Paniestichus subsolianus, Abacophrastus millei, Abacophrastus chapes, Abacophrastus carnifex, Abacophrastus hobbit, Abacophrastus megalops, Abacophrastus reflexus and Abacophrastus bellorum. Abacoleptus curtus new species, is described. Notonomus irideus and Notonomus savesi are moved to Prosopogmus. Four new species of Prosopogmus are described: Prosopogmus koghisensis, Prosopogmus lescheni, Prosopogmus fortis and Prosopogmus aoupiniensis. Homalosoma griseolum is moved to Sphodrosomus. Cerabilia is newly recorded from New Caledonia and the genus is moved from Platynini to Loxandrini and therefore is the first report of Loxandrini from New Caledonia. An apparent adventive from Australia, Darodilia, is newly reported from New Caledonia.     

Phylogeny of minute carabid beetles and their relatives based upon DNA sequence data (Coleoptera, Carabidae, Trechitae)

The phylogeny of ground beetles of supertribe Trechitae is inferred using DNA sequences of genes that code for 28S ribosomal RNA, 18S ribosomal RNA, and wingless. Within the outgroups, austral psydrines are inferred to be monophyletic, and separate from the three genera of true Psydrina (Psydrus, Nomius, Laccocenus); the austral psydrines are formally removed from Psydrini and are treated herein as their own tribe, Moriomorphini Sloane. All three genes place Gehringia with Psydrina. Trechitae is inferred to be monophyletic, and sister to Patrobini.Within trechites, evidence is presented that Tasmanitachoides is not a tachyine, but is instead a member of Trechini. Perileptus is a member of subtribe Trechodina. Against Erwin's hypothesis of anillines as a polyphyletic lineage derived from the tachyine genus Paratachys, the anillines sampled are monophyletic, and not related to Paratachys. Zolini, Pogonini, Tachyina, and Xystosomina are all monophyletic, with the latter two being sister groups. The relationships of the subtribe Bembidiina were studied in greater detail. Phrypeus is only distantly related to Bembidion, and there is no evidence from sequence data that it belongs within Bembidiina. Three groups that have been recently considered to be outside of the large genus Bembidion are shown to be derived members of Bembidion, related to subgroups: Cillenus is related to the Ocydromus complex of Bembidion, Zecillenus is related to the New Zealand subgenus Zeplataphus, and Hydrium is close to subgenus Metallina. The relationships among major lineages of Trechitae are not, however, resolved with these data.     

Juvenile Survival and Development in Euseius Finlandicus, Typhlodromus Pyri and Kampimodromus Aberrans (Acari: Phytoseiidae) Feeding on Con- and Heterospecific Immatures

Juvenile survival and development in Euseius finlandicus (Oudemans), Typhlodromus pyri Scheuten and Kampimodromus aberrans (Oudemans) feeding on con- and heterospecific phytoseiid immatures were investigated in the laboratory at 25 ± 1 °C and 65 ± 5% RH. More than 50% of T. pyri protonymphs preying on larvae of K. aberrans or E. finlandicus reached the adult stage. The mean developmental time of T. pyri from the protonymphal stage to adulthood was 6.3 days when feeding on K. aberrans and 7.5 days when feeding on E. finlandicus. The majority (approximately 90%) of K. aberrans protonymphs feeding on larvae of T. pyri or E. finlandicus died before reaching the deutonymphal stage; in both cases only one individual completed juvenile development. Euseius finlandicus larvae require food to reach the subsequent life stage, in contrast to larvae of T. pyri and K. aberrans, which usually do not feed at all: 10% of E. finlandicus immatures feeding on larvae of K. aberrans or T. pyri completed juvenile development (mean developmental time from larva to adult 7.0 and 6.7 days, respectively). Cannibalizing immatures of T. pyri and K. aberrans were able to reach adulthood, whereas those of E. finlandicus were not. Unfed immatures of T. pyri lived longer than the corresponding stages of E. finlandicus and K. aberrans. The present study indicates that phytoseiid immatures are suitable prey for developing stages of polyphagous phytoseiids. Since E. finlandicus, T. pyri and K. aberrans partly inhabit the same plant species, their immatures can be regarded as potential prey for competitive phytoseiids in times of food scarcity.     

The relationship between British ground beetles (Coleoptera, Carabidae) and land cover

Aims and methods Ground beetle and satellite‐derived land cover data from 1687 United Kingdom 10 km national grid squares were used to assess the relationship between species pool and cover data in Great Britain using fuzzy classification and constrained ordination. Results Ground beetle species pools classified into nine groups which were related to land cover variables using constrained ordination. There was a strong relationship between upland land cover and three ground beetle groups. Deciduous woodland, coastal and tilled land were associated with three other groups. Three further groups did not appear to be strongly associated with any particular cover, but differed in geographical position. Conclusion The distribution of species pools derived from the British national recording scheme at the 10 km scale was strongly related to satellite‐derived land cover data. There appears to be considerable potential for the use of a synthesis of land cover and ground beetle data in the monitoring of environmental change over a large, countrywide, area.     

Laboratory and field tests of predation on the cereal leaf beetle,Oulema melanopus (Coleoptera: Chrysomelidae)

The cereal leaf beetle (CLB), Oulema melanopus (L.) (Coleoptera: Chrysomelidae), is an invasive pest in North America recently reported in the Canadian Prairies. We performed a series of laboratory assays to identify potential predators and a field study to quantify predation of CLB eggs. In no-choice Petri dish assays, ground beetles (Carabidae), rove beetles (Staphylinidae), and several common lady beetle species (Coccinellidae) were the most consistent predators of eggs and larvae. Nabis spp. (Hemiptera: Nabidae) and wolf spiders (Araneae: Lycosidae) consumed many larvae, but did not consume eggs. Hippodamia spp., Coccinella septempunctata (L.) (Coleoptera: Coccinellidae), and Pterostichus melanarius (Illiger) (Coleoptera: Carabidae) also fed on CLB eggs on potted plants when an alternative food source was available, Sitobion avenae (Fabricius) (Hemiptera: Aphididae). In our field study, we found an average of 24.5% of sentinel eggs disappeared over a 24?h period, likely due to predation. Our results suggest that generalist predators can play an important role in the biological control of CLB, and warrant further study.     

Karyotypes of Bembidion quadrimaculatum (L.) and Clivina fossor (L.) (Coleoptera: Carabidae)

Bembidion quadrimaculatum possesses 24 chromosomes: 2n male = 22 + XY, 2n female = 22 + XX; their structure is meta- and submetacentric and differences in length between them are slight. Achiasmatic meiosis has been identified in spermatogenesis. The diploid chromosome number in Clivina fossor is 44; 2n male = 42 + XY, 2n female = 42 + XX. The chromosome structure is meta-, submeta-, and subtelocentric and X is the longest element in the set. 1 to 2 chiasmata per bivalent occur in meiosis.     

The effects of body size on mating and reproduction in Brachinus lateralis (Coleoptera: Carabidae)

Abstract. 1. The causes and reproductive consequences of body size variation of Brachinus lateralis Dejean, a parasitic carabid beetle, were investigated.
2. Body size variation occurs within and between sites. Host size has a major influence on body size of the adult.
3. Fecundity is positively correlated with body size. Egg size is not correlated with body size.
4. Mating males tend to be larger than non-mating males. There is a positive correlation of body sizes in mating pairs.
5. Limited opportunity for host choice may maintain size variation despite the advantages of large size.
6. The non-random patterns of mating for a species without obvious intrasexual aggression suggest that subtle means of male-male competition or female choice may be important.     

Three new species of the aphaenopsian trechine genus Pilosaphaenops Deuve & Tian, 2008 from South China Karst (Coleoptera: Carabidae: Trechinae)

Summary

Three new trechine species of the genus Pilosaphaenops Deuve & Tian, 2008, P. qianzhii n. sp. from cave Lubian Dong in Pingtang County, southern Guizhou Province, P. mengzhenae n. sp. and P. weiguofui n. sp. from cave Xia Dong in Nandan County, and cave Shenlong Gong in Huanjiang County respectively, northern Guangxi Zhuang Autonomous Region, are described and illustrated. A key to all known species of this genus is also provided.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:170C467F-5421-49AD-B1B1-091D8BD58B88     

三种捕食性瓢虫成虫对卵的种内自残及其集团内捕食作用

捕食性瓢虫是农田生态系中一类重要的天敌昆虫,种内自残和集团内捕食现象在捕食性瓢虫中普遍存在。本研究在室内通过选择性和非选择性试验比较分析了异色瓢虫、七星瓢虫及龟纹瓢虫成虫对卵的种内自残和集团内捕食作用以及卵表面的化学物质对集团内捕食作用的影响。结果表明:在非选择性试验中,3种捕食性瓢虫成虫对卵表现出相似的取食现象,即对龟纹瓢虫卵取食最多,其次为七星瓢虫卵,对异色瓢虫卵取食相对较少;在选择性试验中,七星瓢虫和龟纹瓢虫较偏好取食同种卵,对异色瓢虫卵取食均较少;而异色瓢虫喜欢取食异种卵,对同种卵取食相对较少。3种瓢虫卵经正己烷漂洗后,异色瓢虫、七星瓢虫和龟纹瓢虫成虫却未对卵表现出取食偏好性。本研究可为捕食性瓢虫组合释放与协调利用、田间集团内捕食作用评定及其在生物防治中的应用提供理论依据。