Beetle Genus Research Articles

Notes on Malagasy Discheramocephalus Johnson (Coleoptera: Ptiliidae).

Two species of the featherwing beetle genus Discheramocephalus Johnson are known to occur in Madagascar. One of them is known from females only, and some important morphological structures have never been described and illustrated, including details of male genitalia. Morphology of the male of D. bisulcatus Darby is illustrated and described for the first time, including the aedeagus and abdominal structures, and the male genitalia of D. vasilii Darby are also illustrated in detail for the first time. Diagnoses of both species are emended to include newly described structures.

A new genus of wounded-tree beetles from mid-Cretaceous northern Myanmar amber (Coleoptera: Nosodendridae)

The wounded-tree beetles (Nosodendridae) are a small and enigmatic polyphagan family with just under 100 species in two extant genera comprising minute round-oval beetles associated with fermenting tree sap. Here we describe the first extinct genus of Nosodendridae from mid-Cretaceous Burmese amber from northern Myanmar (ca. 99 Ma). Basinosa pengweii gen. et sp. nov. can be distinguished from extant genera by a combination of potentially plesiomorphic characters, namely its strongly protuberant compound eyes, long prosternum, slender tarsi, elongate tibiae not strongly widened apically, and metacoxae narrowly separated by a sharp anterior process of the basalmost abdominal ventrite. The new fossil provides further evidence of an ancient origin of Nosodendridae and a ‘missing link’ between the family and more basal polyphagan superfamilies.

Dispersal constraints on the potential distribution of cold‐adapted stag beetles (genus Platycerus) in Japan and the implications of climate change

Abstract The effects of climate change on species distribution are typically inferred based on species distribution models (SDMs) that do not account for the dispersal ability of species. Here we investigated the utility of dispersal ability measures in predicting the distribution of 10 Platycerus species in Japan, which are cold‐adapted stag beetles sharing ecological and morphological features. We generated three SDMs based on environmental variables without dispersal constraint and incorporating two alternative dispersal constraint scenarios. We compared these three models with respect to SDM performance and the predicted degree of range overlap between neighbouring species. Using the best models among three SDMs, we predicted range shifts under climate change. Additionally, we characterised environmental differences among species distributional areas. Our results revealed that models incorporating dispersal constraints had better predictive performance. Platycerus delicatulus occupied a largest suitable habitat and P. sue had a narrow range in Japan. Most of Platycerus taxa in 2070 were predicted to lose large portions of present suitable areas. Moreover, environment was confirmed to affect the distribution of the targeted species. Incorporating dispersal ability to better understand the effects of climate change on the species ranges is a crucial step towards developing policies for insect management and conservation of vulnerable species.

Revision of the <em>Calotheca nigrotessellata</em> species group from southern Africa, with description of two new species (Coleoptera: Chrysomelidae, Galerucinae, Alticini)

Calotheca Heyden is a mostly sub-Saharan flea beetle genus, comprising twenty-seven species previously included in Blepharida Chevrolat. The examination of new material is revealing a high species richness, as there is high intraspecific variability. Calotheca luteomaculata sp. nov. from Zimbabwe and the Republic of South Africa, and C. luteotessellata sp. nov. from the Republic of South Africa are here described and attributed to the C. nigrotessellata (Baly) species group, mainly based on genitalic characters. Photographs of the main diagnostic characters are supplied, including the median lobe of the aedeagus and spermatheca. A forward stepwise discriminant function analysis, using morphometric variables, has been performed. It supports the attribution of the examined specimens to the three species here considered, thus adding characters useful for their identification. Information on geographical distribution and host plants are also provided.

An update on the distribution of the poorly known flower beetle genus Cymophorus Kirby, 1827 (Coleoptera: Scarabaeidae: Cetoniinae) in Asia.

The genus Cymophorus Kirby, 1827 in Asia is represented by the single species C. pulchellus Arrow, 1910. This rare species is traditionally divided into two subspecies, the nominate subspecies from India and C. pulchellus tonkinensis Schein, 1954 from Indochina. While recently, the latter was informally treated as a synonym of C. pulchellus. By examining type material and additional specimens, the differences in the external features between the individuals from the two regions are reconsidered, and the two taxa are probably not identical. Precise localities of C. pulchellus tonkinensis in China are given, and geographic distribution of both subspecies is summarized in a map.

Elevated rates of positive selection drive the evolution of pestiferousness in the Colorado potato beetle (Leptinotarsa decemlineata, Say)

Contextualizing evolutionary history and identifying genomic features of an insect that might contribute to its pest status is important in developing early detection and control tactics. In order to understand the evolution of pestiferousness, which we define as the accumulation of traits that contribute to an insect population's success in an agroecosystem, we tested the importance of known genomic properties associated with rapid adaptation in the Colorado potato beetle (CPB), Leptinotarsa decemlineata Say. Within the leaf beetle genus Leptinotarsa, only CPB, and a few populations therein, has risen to pest status on cultivated nightshades, Solanum. Using whole genomes from ten closely related Leptinotarsa species native to the United States, we reconstructed a high-quality species tree and used this phylogenetic framework to assess evolutionary patterns in four genomic features of rapid adaptation: standing genetic variation, gene family expansion and contraction, transposable element abundance and location, and positive selection at protein-coding genes. Throughout approximately 20 million years of history, Leptinotarsa species show little evidence of gene family turnover and transposable element variation. However, there is a clear pattern of CPB experiencing higher rates of positive selection on protein-coding genes. We determine that these rates are associated with greater standing genetic variation due to larger effective population size, which supports the theory that the demographic history contributes to rates of protein evolution. Furthermore, we identify a suite of coding genes under positive selection that are putatively associated with pestiferousness in the Colorado potato beetle lineage. They are involved in the biological processes of xenobiotic detoxification, chemosensation and hormone function.

Mesapalochrus pseudorestrictus, a new genus and species of soft-winged flower beetle of the tribe Apalochrini (Coleoptera: Malachiidae) from Africa

Mesapalochrus pseudorestrictus, a new genus and species of soft-winged flower beetle of the tribe Apalochrini (Coleoptera: Malachiidae) from Africa

Influence of the Mediterranean basin history on the origin and evolution of the halophile tiger beetle genus Cephalota (Coleoptera: Cicindelidae)

Summary The distribution area of the halophile tiger beetle genus Cephalota ranges from the Mediterranean Sea to Central Asia, including some endemics restricted to reduced areas in the Iberian Peninsula and Central Asia, such as the critically endangered Cephalota (Taenidia) deserticoloides in Spain. The origin of this genus has been traditionally related to the closure of the Tethys Ocean and the formation of the Mediterranean Sea. In this work, a phylogenetic tree of nine Cephalota species is inferred. The observed phylogenetic relationships between these species challenge the hypotheses previously formulated about the evolution of this group, as the origin of Cephalota is dated back 13.5 million years, once the Mediterranean Sea was already formed. Alternative hypotheses concerning the changes on the suitable habitat for this halophile group caused by fluctuating levels of the Mediterranean Sea are proposed. Additionally, the results do not support the established classification of this genus, suggesting that a taxonomic revision is necessary.

A new species of Horniolus Weise with remarks on the systematic position of the genus (Coleoptera: Coccinellidae).

Horniolus Weise is an Asian genus of ladybird beetles up to now comprising 15 species with the greatest diversity in China. A new species, H. minutus sp. nov., is described and illustrated. The position of the genus within the modern classification of Coccinellidae is discussed, and its transfer from the tribe Scymnini to Platynaspini is proposed.

A New Fossil Genus of False Blister Beetles (Coleoptera: Oedemeridae) from mid-Cretaceous Burmese Amber

In this article, a new genus with four new species of the family Oedemeridae from mid- Cretaceous Burmese amber are described and illustrated. Ditysparedrus n. gen. differs from other genera of the subfamily in the short ventrite I and pyriform elytra. Key to new species of this genus is given.

A remarkable new species of the rove beetle genus Anthobium Leach, 1819 from Eocene Baltic amber (Coleoptera, Staphylinidae, Omaliinae).

An unusual new omaliine species, Anthobium alekseevisp. nov., is described and illustrated from Eocene Baltic amber, tentatively placed in the megadiverse genus Anthobium Leach, 1819. A new monotypic species-group is established. The new species can easily be distinguished from other species of the genus by the larger body, shape of the subrectangular pronotum, and the presence of a median carina on the prosternum and large, subtriangular tooth on the inner side of each mesotibia, likely exhibiting a peculiar sexual dimorphism in the male. Based on the study of the specimen with support of microtomographic images, a brief comparative analysis of a new species with described extant species of Anthobium is provided.

Evolutionary history and eco‐climatic diversification in southern African dung beetle Sisyphus

AbstractAimThe high diversity of species in southern Africa has been attributed to geological and palaeoclimatic factors. The timing of radiations in some groups is held to be linked to these geoclimatic trends. Using the Scarabaeinae dung beetle genus, Sisyphus, as a model system, we investigate how geological uplift and climatic changes in the late Cenozoic affected its diversification patterns in southern Africa.LocationSouthern Africa.TaxonThe dung beetle genus, Sisyphus Latreille, 1807 (Coleoptera: Scarabaeidae: Scarabaeinae).MethodsA dated molecular phylogeny of southern African Sisyphus was compared with a factor analysis of species distribution data that statistically defined groups of species according to current climatic distribution. We used these climatic clusters to estimate ancestral ranges using the “BioGeoBEARS” R package. A lineage through time plot was calculated using the R package ‘APE’. We used Bayesian diversification models (compound Poisson process on mass extinction times) to test hypotheses on how late Cenozoic uplift and climatic changes affected speciation and extinction of Sisyphus. Furthermore, we implemented ecological niche modelling in MaxEnt to predict the habitat suitability of species under present climatic conditions.ResultsFour species groups defined from factor analysis of current climatic distribution data are primarily restricted to the moist summer rainfall region in the northeast. Species diversification occurred from the mid‐Miocene until the Pleistocene, during which the central southern African plateau was uplifted in tandem with the advent of winter rainfall and arid climatic zones to the southwest. The ancestor of Sisyphus was centred in eastern low to mid‐altitude areas. Speciation rates were higher in the Miocene to Pliocene, followed by a dramatic drop during the transition to the Pleistocene.Main conclusionsThe taxonomic and eco‐climatic diversification of sisyphines is coincident with geological uplift and changes in climate in east‐central southern Africa. However, phylogenetic relationships of southern African Sisyphus species are not homogenously distributed with respect to geography and climate.

A new genus and species of the soft flower beetles tribe Apalochrini (Coleoptera: Malachiidae) from Africa

A new genus and species of the soft flower beetles tribe Apalochrini (Coleoptera: Malachiidae) from Africa

Three new species and DNA sequence data of the rare South American water beetle genus Adelphydraena Perkins, 1989 (Coleoptera: Hydraenidae).

Three new species of the very rarely collected water beetle genus Adelphydraena Perkins, 1989 are described from Brazil, Guyana, and Suriname. Illustrations of the male genitalia of the two previously known species in the genus, A. orchymonti Perkins and A. spangleri Perkins from Venezuela, are presented for the first time. High resolution digital images of the habitus of all species are given, and geographical distributions mapped. New species described are Adelphydraena amazonica n. sp. (Brazil), A. spinosa n. sp. (Guyana), and A. surinamensis n. sp. (Suriname). Mitochondrial and nuclear DNA sequence data is given for three of the five species currently known (A. orchymonti, A. spangleri, and A. amazonica). The monophyly of the genus Adelphydraena was strongly supported, but relationships between the sequenced species remain uncertain.

Notes on the Morphology and Distribution of the Himalayan Genus Pseudothilmanus, Including the First Record of the Genus from Nepal (Coleoptera: Rhagophthalmidae)

Pseudothilmanus Pic, 1918 is a genus of beetles currently placed in Rhagophthalmidae. The species P. alatus Pic, 1918 and P. marginatus Pic, 1918 were described based on single holotypes from India with little descriptive information. Later, in a revision of the genus, a new specimen of P. alatus was examined, but also without specific locality. This paper provides the description of the wing venation and new distributional records for this genus, including the first record in Nepal.

Trihelota, a new and unusual helotid beetle genus from mid-Cretaceous Burmese amber (Coleoptera: Helotidae)

A new genus belonging to the cucujoid family Helotidae, Trihelota gen. nov., is described from mid-Cretaceous (ca.99 million years old) amber from Kachin State, northern Myanmar, containing a single species T. fulvata sp. nov. The minute fossil was documented using fluorescence microscopy and X-ray microtomography to reveal fine morphological details. Trihelota is characterised by its transverse head, antennal club about 1.5 times longer than wide, pronotum almost parallel-sided, and elytra not costate. Notably, each elytron possesses three coloured spots, a character unique within Helotidae. The new genus considerably expands the known morphological disparity of Cretaceous helotids. A keyto extinct and extant genera of the family Helotidae is provided along with a checklist of fossil species.

Serotonin signaling suppresses the nutrition-responsive induction of an alternate male morph in horn polyphenic beetles.

Environment-responsive development contributes significantly to the phenotypic variation visible to selectionand as such possesses the potential to shape evolutionary trajectories. However, evaluation of the contributions of developmental plasticity to evolutionary diversification necessitates an understanding of the developmental mechanisms underpinning plastic trait expression. We investigated the role of serotonin signaling in the regulation and evolution of horn polyphenism in the beetle genus Onthophagus. Specifically, we assessed the role of serotonin in development by determining whether manipulating serotonin biosynthesis during the larval stage alters body size, developmental rate, and the formation of relative adult trait size in traits characterized by minimal (genitalia), moderate (elytra), and pronounced (horns) nutrition-responsive development in O. taurus. Second, we assessed serotonin's role in evolution by replicating a subset of our approaches across four species reflecting ancestral as well as derived conditions. Lastly, we employed immunohistochemical approaches to begin assessing whether serotonin may be acting via the endocrine or nervous system. Our results show that pharmacological manipulation of serotonin signaling affects overall size, developmental rate, and the body size threshold separating alternate male morphs. Threshold body sizes were affected across species, regardless of the severity of horn polyphenism, and independent of the precise morphological location of horns. However, histological assessments suggest it is unlikely serotonin functions as a neurotransmitter and instead may rely on other mechanisms that remain to be identified. We discuss the most important implications of our results for our understanding of the evolution of and through plasticity in horned beetles and beyond.

The unknown larva of the burrowing water beetle genus Liocanthydrus Guignot, 1957 (Coleoptera: Noteridae)

ABSTRACT The instar III larva of Liocanthydrus clayae (J. Balfour-Browne, 1969) is described and illustrated, including morphometric and chaetotaxic analyses of the cephalic capsule, head appendages, legs, last abdominal segment, and urogomphus. Larvae of Liocanthydrus Guignot, 1957, can be readily separated from other known noterid larvae by the presence of two short posterodorsal projections on the last abdominal segment. Regarding chaetotaxy, Liocanthydrus differs from Suphis Aubé, 1836, Hydrocanthus Say, 1823 and Suphisellus Crotch, 1873 in the position of seta AN7, the shape of seta CO13, the shape and length of setae FE6 and TI7, and the length of seta UR8.

New Liodessus species from the high Andes of Peru (Coleoptera: Dytiscidae, Bidessini).

We describe four new species of the diving beetle genus Liodessus Guignot from the high Andean regions of Peru: Liodessus alpinus sp. nov. from Junín, L. hauthi sp. nov. from Huánuco and Churubamba, L. rhigos sp. nov. from Junín, and L. thespesios sp. nov. from Cusco. We delineate the species using morphological structures and provide a 5' mitochondrial cytochrome c oxidase 1 database on the Barcode of Life Data System (BOLD). We also provide taxonomic notes on Liodessus acollensis Guignot, 1955 and L. andinus Guignot, 1957, described from the high Andes of Peru and Bolivia. These species occur at higher altitudes above 3,400 m and up to 4,900 m, and were collected in shallow, exposed peatland pools and puddles, mostly in steppes and high Andean Puna. The known distribution and habitat preferences of each species are outlined briefly.

Habitat use of co-occurring burying beetles (genusNicrophorus) in southeastern Ontario, Canada

The coexistence of closely related species plays an important role in shaping local diversity. However, competition for shared resources can limit the ability of species to coexist. Many species avoid the costs of coexistence by diverging in habitat use, known as habitat partitioning. We examine patterns of habitat use in seven co-occurring species of burying beetles (genus Nicrophorus Fabricius, 1775), testing the hypothesis that Nicrophorus species partition resources by occupying distinct habitats. We surveyed Nicrophorus abundance and 54 habitat characteristics at 100 random sites spanning an environmentally diverse region of southeastern Ontario, Canada. We found that three species occupied distinct habitat types consistent with habitat partitioning. Specifically, Nicrophorus pustulatus Herschel, 1807, Nicrophorus hebes Kirby, 1837, and Nicrophorus marginatus Fabricius, 1801 appear to be specialists for forest canopy, wetlands, and open fields, respectively. In contrast, Nicrophorus orbicollis Say, 1825, Nicrophorus sayi Laporte, 1840, and Nicrophorus tomentosus Weber, 1801 appear to be generalists with wide breadths of habitat use. We were unable to identify the habitat associations of Nicrophorus defodiens Mannerheim, 1846. Our findings are consistent with habitat acting as an important resource axis along which some Nicrophorus species partition; however, divergence along other resource axes (e.g., temporal partitioning) also appears important for Nicrophorus coexistence.