World reclassification of the Cardiophorinae (Coleoptera, Elateridae), based on phylogenetic analyses of morphological characters

Matrix-based key to the click beetle genera of Canada and USA with a summary of habitat use (Coleoptera, Elateridae)

The Elateridae, or click beetles are abundant and diverse in most terrestrial ecosystems in North America, acting as plant pests and filling many other ecological roles. The 112 genera of Elateridae Leach, 1815, or click beetles, known from Canada and USA are included in a first comprehensive digital interactive key to adults. A link to an online peer-reviewed LUCID key to elaterid genera and downloadable LUCID files are provided. Diagnostic morphological summaries using information from the 61 characters and 158 character states of the matrix key are presented for all genera. A table summarizes current understanding of habitat use by all elaterid genera in Canada and USA from literature, collections, citizen science, and our own observations. Diversity of elaterid genera was high throughout warm and cool temperate regions, especially in mountainous areas and mesic woodlands. Larvae of most genera were associated with soil, litter and decaying wood.

Taxonomic revision of the genus Penia Laporte (Coleoptera, Elateridae, Dendrometrinae) from Taiwan

The genus Penia Laporte, 1838 (tribe Dimini Candze, 1863, subfamily Dendrometrinae Gistel, 1848) has three known endemic species from Taiwan. However, little is still known about these species and their important features, including genitalia. Here, the taxonomy of Taiwanese Penia is revised and eight species are confirmed: Penia alishanensis sp. nov., P. babai Kishii, 1994, P. elongata sp. nov., P. inopinata sp. nov., P. pulla sp. nov., P. smetanai Schimmel, 1996, P. takasago Kishii, 1997, and P. tsou sp. nov. The paratype of P. takasago is a different species and the species is described as P. inopinata. Three species have elongated bodies (P. alishanensis, P. elongata, and P. smetanai), whereas the other five have broad bodies. The eight species are distinguished from each other by the sizes of the eyes and apical maxillary palpomeres, the lengths of antennae and elytra, the relative length of the basal antennomeres, the degree of development of the mesosternal process between mesocoxae, and the shapes of the pronotum, hypomeron, scutellar shield and abdominal ventrite V. A key to all species in Taiwan is provided.

Click beetles (Coleoptera: Elateridae) of Khuzestan province (Iran): with three new species, Craspedostethus izehensis sp.n., Dicronychus khuzestanicus sp. n. and Gurjevelater catei sp. n

More than 730 specimens of Elateridae were collected in Khuzestan province. Thirty three species belonging to 18 genera and five subfamilies are listed. Three new species, Craspedostethus izehensis sp. n., Dicronychus khuzestanicus sp. n., Gurjevelater catei sp. n. are described, along with the female of Aeoloides iranicus Platia & Gudenzi, 2002. Dicronychus houschkai Platia, 2011 is recorded as a new species to Iran. A distributional map and climate data for each species, along with photographs of habitus and genitalia of eight species are presented.

Annotated checklist of the beetles (Coleoptera) of the California Channel Islands

The beetle fauna of the California Channel Islands is here enumerated for the first time in over 120 years. We provide an annotated checklist documenting species-by-island diversity from an exhaustive literature review and analysis of a compiled dataset of 26,609 digitized specimen records to which were added over 3,000 individual specimen determinations. We report 825 unique species from 514 genera and 71 families (including 17 new family records) comprising 1,829 species-by-island records. Species totals for each island are as follows: Anacapa (74); San Clemente (197); San Miguel (138); San Nicolas (146); Santa Barbara (64); Santa Catalina (370); Santa Cruz (503); and Santa Rosa (337). This represents the largest list of species published to date for any taxonomic group of animals on the Channel Islands; despite this, we consider the checklist to be preliminary. We present evidence that both inventory and taxonomic efforts on Channel Islands beetles are far from complete. Rarefaction estimates indicate there are at least several hundred more species of beetles yet to be recorded from the islands. Despite the incomplete nature of existing records, we found that species diversity is highly correlated with island area. We report 56 species which are putatively geographically restricted (endemic) to the Channel Islands, with two additional species of questionable endemic status. We also report 52 species from the islands which do not natively occur in the southern California region.

Systematic review of the firefly genus Emeia Fu, Ballantyne & Lambkin, 2012 (Coleoptera, Lampyridae) from China

The Luciolinae genus Emeia Fu, Ballantyne & Lambkin, 2012 is reviewed. Phylogenetic relationships based on cox1 DNA barcoding sequences from 42 fireflies and 2 outgroup species are reconstructed. The dataset included three main Lampyridae subfamilies: Luciolinae, Photurinae and Lampyrinae, and Emeia was recovered within Luciolinae. A new species, Emeiapulchra Zhu & Zhen sp. nov., is described from the wetland of Lishui, Zhejiang, China. Emeiapulchra is sister species to E.pseudosauteri from Sichuan, which is supported by morphological characters and a phylogeny based on DNA barcoding sequences. The two species are separated geographically as shown on the distribution map. A key to species of Emeia using males is provided.

Functional Morphology of the Thorax of the Click Beetle Campsosternus auratus (Coleoptera, Elateridae), with an Emphasis on Its Jumping Mechanism

Simple Summary

Click beetles are well-known for the specialized thoracic structure, which they can click to thrust themselves into the air and to right themselves. Several aspects of their jumping mechanism were still not entirely clear prior to this study. We utilized traditional dissection, 3D virtual dissection, and high-speed filming techniques to investigate the functional morphology of their thorax. Our results show several new insights into their extraordinary clicking and jumping mechanisms.

Abstract

We investigated and described the thoracic structures, jumping mechanism, and promesothoracic interlocking mechanism of the click beetle Campsosternus auratus (Drury) (Elateridae: Dendrometrinae). Two experiments were conducted to reveal the critical muscles and sclerites involved in the jumping mechanism. They showed that M2 and M4 are essential clicking-related muscles. The prosternal process, the prosternal rest of the mesoventrite, the mesoventral cavity, the base of the elytra, and the posterodorsal evagination of the pronotum are critical clicking-related sclerites. The destruction of any of these muscles and sclerites resulted in the loss of normal clicking and jumping ability. The mesonotum was identified as a highly specialized saddle-shaped biological spring that can store elastic energy and release it abruptly. During the jumping process of C. auratus, M2 contracts to establish and latch the clicking system, and M4 contracts to generate energy. The specialized thoracic biological springs (e.g., the prosternum and mesonotum) and elastic cuticles store and abruptly release the colossal energy, which explosively raises the beetle body in a few milliseconds. The specialized trigger muscle for the release of the clicking was not found; our study supports the theory that the triggering of the clicking is due to the building-up of tension (i.e., elastic energy) in the system.

Anchored Phylogenomics, Evolution and Systematics of Elateridae: Are All Bioluminescent Elateroidea Derived Click Beetles?

Simple Summary

In the era of phylogenomics, new molecular sequencing and computational techniques can aid in resolving phylogenetic relationships that were previously intractable by morphological or limited molecular data. In this study, we used anchored hybrid enrichment—designed to recover DNA sequences from hundreds of single-copy orthologous genes—to resolve the phylogeny of the Elateridae (click-beetles) and establish their placement within superfamily Elateroidea. The resulting data were compatible with published transcriptomes, allowing for integrating our dataset with previously published data. Using a wide range of analyses on these molecular data, we tested hypotheses long-debated in the morphological literature and also the robustness of our phylogenetic inferences. Our results placed the bioluminescent lampyroids (fireflies and relatives) within the click-beetles, challenging the current classification of Elateridae, Lampyridae, Phengodidae, and Rhagophthalmidae. However, despite the large amount of molecular data analyzed, a few nodes with conflicting phylogenetic signals could not be unambiguously resolved. Overall, we recovered well-resolved tree topologies that will serve as a framework for further systematic and evolutionary studies of click-beetles. This work further demonstrates that the click-beetle lineage contains not only pest wireworms, but also many species that benefit agriculture.

Abstract

Click-beetles (Coleoptera: Elateridae) are an abundant, diverse, and economically important beetle family that includes bioluminescent species. To date, molecular phylogenies have sampled relatively few taxa and genes, incompletely resolving subfamily level relationships. We present a novel probe set for anchored hybrid enrichment of 2260 single-copy orthologous genes in Elateroidea. Using these probes, we undertook the largest phylogenomic study of Elateroidea to date (99 Elateroidea, including 86 Elateridae, plus 5 non-elateroid outgroups). We sequenced specimens from 88 taxa to test the monophyly of families, subfamilies and tribes. Maximum likelihood and coalescent phylogenetic analyses produced well-resolved topologies. Notably, the included non-elaterid bioluminescent families (Lampyridae + Phengodidae + Rhagophthalmidae) form a clade within the otherwise monophyletic Elateridae, and Sinopyrophoridae may not warrant recognition as a family. All analyses recovered the elaterid subfamilies Elaterinae, Agrypninae, Cardiophorinae, Negastriinae, Pityobiinae, and Tetralobinae as monophyletic. Our results were conflicting on whether the hypnoidines are sister to Dendrometrinae or Cardiophorinae + Negastriinae. Moreover, we show that fossils with the eucnemid-type frons and elongate cylindrical shape may belong to Eucnemidae, Elateridae: Thylacosterninae, ancestral hard-bodied cantharoids or related extinct groups. Proposed taxonomic changes include recognition of Plastocerini as a tribe in Dendrometrinae and Hypnoidinae stat. nov. as a subfamily within Elateridae.

The Fossil Record of Elateridae (Coleoptera: Elateroidea): Described Species, Current Problems and Future Prospects

The Elateridae (click-beetles) are the largest family in Elateroidea; however, their relationships, systematics and classification remain unclear. Our understanding of the origin, evolution, palaeodiversity and palaeobiogeography of Elateridae, as well as reconstruction of a reliable time-calibrated phylogeny for the group, are hampered by the lack of detailed knowledge of their fossil record. In this study, we summarize the current knowledge on all described fossil species in Elateridae, including their type material, geographic origin, age, bibliography and remarks on their systematic placement. Altogether, 261 fossil species classified in 99 genera and nine subfamilies are currently listed in this family. The Mesozoic click-beetle diversity includes 143 species, with most of them described from the Jurassic Karatau, and 118 described species are known from the Cenozoic deposits, mainly from the Eocene North American Florissant Formation and European Baltic amber. Available data on the described past diversity of Elateridae suggest that almost all fossil lineages in this group are in urgent need of revision and numerous Mesozoic species might belong to different families. Our study is intended to serve as a comprehensive basis for all subsequent research focused on the click-beetle fossil record.

Revision of Chinese Phorocardius species (Coleoptera, Elateridae, Cardiophorinae)

The Chinese species of Phorocardius Fleutiaux, 1931 have been studied and six species are described as new: P. alterlineatus Ruan & Douglas, sp. nov.; P. flavistriolatus Ruan & Douglas, sp. nov.; P. minutus Ruan & Douglas, sp. nov.; P. rufiposterus Ruan & Douglas, sp. nov.; P. yunnanensis Ruan & Douglas, sp. nov.; and P. zhiweii Ruan, Douglas & Qiu, sp. nov. Lectotypes are designated for Cardiophorus comptus Candèze, 1860, Cardiophorus contemptus Candèze, 1860, Phorocardius magnus Fleutiaux, 1931, and Cardiophorus manuleatus Candèze, 1888. The holotype is identified for Cardiophorus yanagiharae Miwa, 1927. Phorocardius florentini (Fleutiaux, 1895) and P. manuleatus (Candèze, 1888) are newly reported from China; P. comptus (Candèze, 1860) is excluded from the Chinese fauna. A key to the 11 Phorocardius species known from China is given. Phorocardius is newly recorded from deep within the Palearctic Region. The procoxal cavities of P. rufiposterus Ruan & Douglas, sp. nov. are closed, which is different from all other species of Phorocardius. An annotated checklist of the 21 Phorocardius species of the world is provided. Additionally, Phorocardius contemptus (Candèze, 1860), comb. nov. is transferred from Cardiophorus to Phorocardius; four species are transferred from Phorocardius to Displatynychus: Displatynychus bombycinus (Candèze, 1895), comb. nov., Displatynychus pakistanicus (Platia & Ahmed, 2016), comb. nov., Displatynychus sobrinus (Laporte, 1840), comb. nov., and Displatynychus tibialis (Platia & Ahmed, 2016), comb. nov.

Fossil Genera in Elateridae (Insecta, Coleoptera): A Triassic Origin and Jurassic Diversification

Insect fossils bear important information about the evolutionary history of the group. The fossil record of Elateridae, a large cosmopolitan beetle family, has been greatly understudied and the available data are often replete with ambiguity and uncertainty. The research of Elateridae evolution cannot be done without solid genus-group name concepts. In this study we provide an updated comprehensive summary of the fossil genera in Elateridae, including their systematic placement and information on the type species, gender, number of species, age range, and relevant bibliography. We list seven valid fossil genera in Agrypninae, one in Cardiophorinae, two in Dendrometrinae, five in Elaterinae, two in Negastriinae, one in Omalisinae, one in Pityobiinae, and 36 in Protagrypninae. Additional 19 genera are tentatively classified as Elateridae incertae sedis, and their placements are discussed. Further, we move genera Babuskaya Martins-Neto & Gallego, 2009, Cardiosyne Martins-Neto & Gallego, 2006, Fengningia Hong, 1984 and Gemelina Martins-Neto & Gallego, 2006 from Elateridae to Coleoptera incertae sedis. We also discuss the genera previously placed in Elateridae, which are currently not included in the family. The data on the fossil generic diversity suggest that Elateridae originated in the Triassic and rapidly diversified and became comparatively abundant through the Jurassic. We call for further research on the fossil Elateridae from various deposits in order to increase our knowledge on the origin, evolution, and palaeodiversity of the group.

World catalogue of the genus-group names in Elateridae (Insecta, Coleoptera). Part I: Agrypninae, Campyloxeninae, Hemiopinae, Lissominae, Oestodinae, Parablacinae, Physodactylinae, Pityobiinae, Subprotelaterinae, Tetralobinae

In this first part of the World catalogue of genus-group names in Elateridae, a nomenclatural review of the genera belonging to ten subfamilies is provided. All names are given with author name, year, and page of publication, type species, and type fixation. We list 132 valid genera in Agrypninae, 2 in Campyloxeninae, 4 in Hemiopinae, 11 in Lissominae, 2 in Oestodinae, 8 in Parablacinae, 2 in Physodactylinae, 2 in Pityobiinae, 1 in Subprotelaterinae, and 7 in Tetralobinae. Genera Anathesis Candèze, 1865, Antitypus Candèze, 1882, Chrostus Candèze, 1878, Dorygonus Candèze, 1859 (with subgenus Rygodonus Fleutiaux, 1932), and Macromalocera Hope, 1834 are tentatively placed as Agrypninaeincertae sedis. Paradrapetesvillosus Fleutiaux, 1895 is designated as the type species for Paradrapetes Fleutiaux, 1895. Two new genera are proposed based on species previously incorrectly used as type species for Abiphis Fleutiaux, 1926 and Lycoreus Candèze, 1857. These genera are Neoabiphis Kundrata & Bouchard, gen. n. (type species: Elaternobilis Illiger, 1800) and Neolycoreus Kundrata & Bouchard, gen. n. (type species: L.regalis Candèze, 1857), respectively. The following new combinations are proposed for species hitherto included in Abiphis Fleutiaux, 1926: Neoabiphiscandezei (Alluaud, 1896), comb. n., N.fairmairei (Fleutiaux, 1903), comb. n., N.goudoti (Fleutiaux, 1942), comb. n., N.insignis (Klug, 1833), comb. n., N.nobilis (Illiger, 1800), comb. n., and N.viettei (Girard, 1966), comb. n. The following new combinations are proposed for species hitherto included in Lycoreus Candèze, 1857: Neolycoreusalluaudi (Candèze, 1900), comb. n., N.corpulentus (Candèze, 1899), comb. n., N.cyclops (Candèze, 1865), comb. n., N.decorsei (Fleutiaux, 1903), comb. n., N.dux (Candèze, 1857), comb. n., N.goudotii (Laporte, 1838), comb. n., N.madagascariensis (Gory, 1832), comb. n., N.oculipennis (Fairmaire, 1903), comb. n., N.orbiculatus (Schwarz, 1901), comb. n., N.regalis (Candèze, 1857), comb. n., N.sicardi (Fleutiaux, 1942), comb. n., N.triangularis (Fleutiaux, 1942), comb. n., N.triocellatus (Laporte, 1838), comb. n., and N.vicinus (Fleutiaux, 1942), comb. n. The following new combinations are proposed for species hitherto incorrectly included in Plectrosternus Lacordaire, 1857: Legnarufa (Lacordaire, 1857), comb. n., L.convexa (Vats, 1991), comb. n., L.coolsi (Schimmel, 1996), comb. n., and L.foveata (Patwardhan & Athalye, 2012), comb. n. This research revealed a nomenclatural problem threatening the stability of the well-established valid genus name Adelocera Latreille, 1829. An application to the International Commission on Zoological Nomenclature will be necessary in this case to maintain stability. Additionally, we act here as First Revisers (ICZN 1999, Art. 24.2) in giving precedence to Lucarius Gistel, 1848 (Staphylinidae) over Lucarius Gistel, 1848 (Elateridae).

Identification of Sex Pheromones and Sex Pheromone Mimics for Two North American Click Beetle Species (Coleoptera: Elateridae) in the Genus Cardiophorus Esch

To date, all known or suspected pheromones of click beetles (Coleoptera: Elateridae) have been identified solely from species native to Europe and Asia; reports of identifications from North American species dating from the 1970s have since proven to be incorrect. While conducting bioassays of pheromones of a longhorned beetle (Coleoptera: Cerambycidae), we serendipitously discovered that males of Cardiophorus tenebrosus L. and Cardiophorus edwardsi Horn were specifically attracted to the cerambycid pheromone fuscumol acetate, (E)-6,10-dimethylundeca-5,9-dien-2-yl acetate, suggesting that this compound might also be a sex pheromone for the two Cardiophorus species. Further field bioassays and electrophysiological assays with the enantiomers of fuscumol acetate determined that males were specifically attracted by the (R)-enantiomer. However, subsequent analyses of extracts of volatiles from female C. tenebrosus and C. edwardsi showed that the females actually produced a different compound, which was identified as (3R,6E)-3,7,11-trimethyl-6,10-dodecadienoic acid methyl ester (methyl (3R,6E)-2,3-dihydrofarnesoate). In field trials, both the racemate and the (R)-enantiomer of the pheromone attracted similar numbers of male beetles, suggesting that the (S)-enantiomer was not interfering with responses to the insect-produced (R)-enantiomer. This report constitutes the first conclusive identification of sex pheromones for any North American click beetle species. Possible reasons for the strong and specific attraction of males to fuscumol acetate, which is markedly different in structure to the actual pheromone, are discussed.