Spectral sensitivity of click beetles (Coleoptera: Elateridae) and their responses to light stimuli in laboratory and field experiments.

With increasingly fewer insecticides registered to control the larvae of pest click beetles (Coleoptera: Elateridae), integrative beetle management, including pheromone- and light-based trapping of adult beetles, must be explored as an alternative strategy. Here, we analyzed the spectral sensitivity and color preference of 9 elaterids across 6 genera in electrophysiological recordings and in behavioral bioassays. In electroretinogram recordings (ERGs), dark-adapted beetles were exposed to narrow wavebands of light in 10-nm increments from 330 to 650 nm. All beetles proved most sensitive to green (515-538 nm) and ultraviolet (UV) light (~360 nm). In 4-choice bioassay arenas with 3 light emitting diodes (LEDs; green [525 nm], blue [470 nm], red [655 nm]) and a dark control as test stimuli, beetles discriminated between test stimuli, being preferentially attracted to green and blue LEDs. In field experiments, Vernon pitfall traps fitted with a green, blue or white LED captured significantly more male and female Agriotes lineatus and A. obscurus than dark control traps. When traps were baited with green or blue LEDs at light intensities that differed by 10-fold, the traps baited with higher light intensity lures captured numerically more beetles but trap catch data in accordance with light intensity did not differ statistically. Light-based trapping may be a viable tool for monitoring elaterid species known not to have pheromones.

Identification of the Major Sex Pheromone Component of the Click Beetle Agriotes ferrugineipennis.

Synthetic sex pheromone lures are useful tools to monitor and control populations of adult click beetles (Coleoptera: Elateridae). However, sex pheromones for Agriotes click beetle species native to North America have yet to be identified. Here we report the identification and field testing of the sex pheromone of Agriotes ferrugineipennis. Headspace volatiles from female beetles were collected on Porapak Q, and aliquots of Porapak extract were analyzed by gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometry. 7-Methyloctyl 7-methyloctanoate (7Me7Me) emitted by females was more abundant and elicited much stronger responses from male antennae than the aldehydes octanal and nonanal and the ketone 6,10,14-trimethyl-2-pentadecanone. In a field experiment, captures of A. ferrugineipennis males in traps baited with candidate pheromone components exceeded those of unbaited control traps, on average by nearly 1,200 times. Neither the ketone nor the aldehydes as lure constituents appeared to alter captures of males in 7Me7Me-baited traps. We conclude that 7Me7Me is the major, and possibly the only, sex attractant pheromone component of female A. ferrugineipennis.

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

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.

Field Evaluation of Selected Plant Volatiles and Conspecific Pheromones as Attractants for Agriotes obscurus and A. lineatus (Coleoptera: Elateridae).

Sex pheromones are commonly used in traps to monitor populations and movements of male click beetles, but to date few attractants have been identified for females. Notable exceptions are plant-derived kairomones for female Agriotes brevis and A. ustulatus, allowing the monitoring of both males and females of these species with lures containing both pheromones and plant volatiles. The attractiveness of these plant volatiles for two congeners, A. obscurus and A. lineatus, which are agricultural pests in Europe and North America, was evaluated in the current study. Both the four-component MINIM plant-derived lure for A. brevis, and the blend of (E)-anethol and (E)-cinnamaldehyde for A. ustulatus, were not attractive to A. obscurus and A. lineatus, and instead appeared to reduce captures-both when compared to blank controls, and when blended with and compared to the sex pheromones of these species. This was most pronounced in A. obscurus, where (E)-anethol and (E)-cinnamaldehyde reduced male captures by 43 and 37%, respectively. Combining the pheromones of A. obscurus and A. lineatus reduced captures of these species by 77 and 19%, respectively, compared to these pheromones singly. This suggests that attractants for female click beetles can be highly species-specific, and that the blending of pheromones of congeneric species with each other, or with plant volatiles, can reduce captures. Further research into developing such attractants for economic species is urgently needed.

Comparative Evaluation of Pitfall Traps for Click Beetles (Coleoptera: Elateridae).

We evaluated the relative efficacy of six pheromone-baited traps used in trapping Agriotes obscurus (L.) click beetles (Coleoptera: Elateridae): original Yatlor Traps, Yatlor Funnel Traps, Vernon Beetle Traps, Unitraps, Baited Pitfall Traps, and Vernon Pitfall Traps. Traps were rated according to quantitative and qualitative criteria of importance for each of four trap uses: general surveys, scientific studies, IPM monitoring, and mass trapping. Measurable quantitative categories included: total catch of A. obscurus; time for assembly, installation, and inspection; exclusion of nontarget invertebrates; and cost. Qualitative criteria were small mammal exclusion, flooding, design and handling variability, and convenience for various field uses. The most desirable characteristics were determined for the above four uses, and the cumulative ranking based on quantitative criteria and all four uses was Vernon Pitfall Trap, Baited Pitfall Trap, Original Yatlor Trap, Vernon Beetle Trap, Yatlor Funnel Trap, and Unitrap.

Species Identification of Wireworms (Agriotes spp.; Coleoptera: Elateridae) of Agricultural Importance in Europe: A New "Horizontal Identification Table".

Wireworms are yellowish soil-dwelling larvae that damage a wide range of arable crops. The most common wireworms found in European cultivated fields (except for the Caucasus) belong to the genus Agriotes (Coleoptera: Elateridae). In several European countries, environment-impacting insecticides are applied on a prophylactic basis to control them. However, before any treatment can be applied, European legislation requires that an assessment is done when pest population levels exceed a damage threshold. The threshold substantially depends on wireworm species, thus quick reliable larval identification is needed to implement the appropriate integrated pest management practices. Furthermore, research into non-chemical strategies involves carrying out tests with live and identified wireworms. Thus, thousands of wireworms were observed in a bid to identify live larvae so that larval density could be assessed and compared with species-specific thresholds before sowing, and laboratory experiments were carried out. This work led to a horizontal identification table that allows for quick and accurate identification of live larvae. This key, unlike traditional dichotomous keys, simultaneously considers a set of multiple discriminating morphological characters in order of stability. The key can be reliably used by less experienced users and, once minimum familiarity is acquired, most larvae can be identified rapidly, with high precision.

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.

The genus Selasia Laporte, 1838 (Coleoptera: Elateridae: Agrypninae) in Sri Lanka.

The neotenic click-beetle genus Selasia Laporte, 1838 has a centre of diversity in the tropical Africa but also includes several species known from the Palearctic and Oriental regions. In this study, we review the Selasia fauna of Sri Lanka. We describe S. ivanae sp. nov., redescribe S. apicalis Pic, 1914, and discuss the systematic placement of S. isabellae Bourgeois, 1909, which is probably a firefly and is considered incertae sedis.

Nonlinear elasticity and damping govern ultrafast dynamics in click beetles.

Many small animals use springs and latches to overcome the mechanical power output limitations of their muscles. Click beetles use springs and latches to bend their bodies at the thoracic hinge and then unbend extremely quickly, resulting in a clicking motion. When unconstrained, this quick clicking motion results in a jump. While the jumping motion has been studied in depth, the physical mechanisms enabling fast unbending have not. Here, we first identify and quantify the phases of the clicking motion: latching, loading, and energy release. We detail the motion kinematics and investigate the governing dynamics (forces) of the energy release. We use high-speed synchrotron X-ray imaging to observe and analyze the motion of the hinge's internal structures of four Elater abruptus specimens. We show evidence that soft cuticle in the hinge contributes to the spring mechanism through rapid recoil. Using spectral analysis and nonlinear system identification, we determine the equation of motion and model the beetle as a nonlinear single-degree-of-freedom oscillator. Quadratic damping and snap-through buckling are identified to be the dominant damping and elastic forces, respectively, driving the angular position during the energy release phase. The methods used in this study provide experimental and analytical guidelines for the analysis of extreme motion, starting from motion observation to identifying the forces causing the movement. The tools demonstrated here can be applied to other organisms to enhance our understanding of the energy storage and release strategies small animals use to achieve extreme accelerations repeatedly.

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.

Description of a new species of Platyparadonus Etzler and Ivie, 2019 (Coleoptera: Elateridae), with an updated key to species.

A new species of the genus Platyparadonus Etzler Ivie, 2019, is described from St. John (United States Virgin Islands). Taxonomic and diagnostic remarks are provided along with a map of distribution and a key to the species. The misinterpretation of female paratypes belonging to P. marleyi Etzler Ivie, 2019 from St. John is also clarified.

First record and new species of the genus Calambus Thomson (Coleoptera, Elateridae, Dendrometrinae) from Taiwan.

Calambus taiwanensis sp. n. is described from Taiwan, as the first record of the genus Calambus. This species is distinguished from its congeners by the male antennae extending beyond the apex of the pronotal hind angles by two apical antennomeres, antennomere III obconical and slightly longer than II, male aedeagus not expanded apically and without lateral subapical barbs, female genitalia with robust baculum and bursa copulatrix without sclerotized piece. The species is not included in any group suggested in past studies. A key to the five genera of the tribe Prosternini from Taiwan is provided.

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.

Review of the genus Paradonus Stibick, 1971 (Elateridae: Negastriinae), with three new North American species.

Three new North American species of Paradonus Stibick are described: Paradonus gallatinensis new species, Paradonus gustafsoni new species and Paradonus stibicki new species is described for specimens formerly called Paradonus pectoralis sensu Stibick, 1991. The type species of the genus, Paradonus pectoralis Say, 1839 is redefined, and the Holotype of Paradonus olivereae Stibick, 1991 is designated as the Neotype of P. pectoralis, a common, widespread species. The genus is redescribed, a checklist of species is included, and notes on the described species north of Mexico are given. Hypnoidus guatemalensis Champion, 1895 is removed from the genus and placed in Zorochros Thompson, 1858 as Zorochros guatemalensis (Champion, 1895) new combination. A key to all described species north of Mexico is provided, along with illustrations of characters used in identifying species.

Comparative Antennal Morphology of Agriotes (Coleoptera: Elateridae), with Special Reference to the Typology and Possible Functions of Sensilla.

Species of the click-beetle genus Agriotes Eschscholtz are economically important crop pests distributed mainly in the Northern Hemisphere. They can inflict considerable damage on various field crops. Therefore, the detection, monitoring, and control of Agriotes include the adult trapping using species-specific sex pheromones, which is a critical component of pest research. To obtain a better understanding of the detailed antennal morphology as background information for subsequent chemical ecology research, we conducted a scanning electron microscopy study of the antennal sensilla of both sexes in 10 European Agriotes species. We identified 16 different sensilla in Agriotes, belonging to six main types: sensilla chaetica (subtypes C1 and C2), sensilla trichodea, sensilla basiconica (subtypes B1-B9), dome-shaped sensilla (subtypes D1 and D2), sensilla campaniformia, and Böhm sensilla. We discuss their possible functions and compare the sensilla of Agriotes with those of other Elateridae in order to consolidate the sensillum nomenclature in this family. Additionally, our study reveals the remarkable interspecific variability in sensillar equipment of Agriotes and identifies several characters of potential importance for future use in systematic studies. The present study provides a strong preliminary framework for subsequent research on the antennal morphology of this crop pest on a wider scale.

Generic Reclassification of Limonius Eschscholtz, 1829 (Elateridae: Dendrometrinae) sensu Candèze 1860 of the World.

The genus Limonius Eschscholtz, 1829 was last treated as a whole by Candèze (1860). Since then, members have been placed in eight other genera: Cidnopus Thomson, 1859; Gambrinus LeConte, 1853; Elathous Reitter, 1890; Kibunea Kishii, 1966; Limoniscus Reitter, 1905; Nothodes LeConte, 1861; Pheletes Kiesenwetter, 1858; and Solskyana Dolin, 1978. Based on the examination of adult and larval characters, five genera are recognized: Elathous Reitter, 1890; Gambrinus LeConte, 1853; Limonius Eschscholtz, 1829; Pheletes Kiesenwetter, 1858; and Tetralimonius new genus. Limoniscus Reitter, 1905 and Sichuanelater Platia and Gudenzi, 2006 are new synonymies of Gambrinus LeConte, 1853; Micrathous Lane, 1971, Neoathousius Schimmel and Platia, 1991 and Solskyana Dolin, 1978 are all new synonymies of Limonius. A total of 84 new combinations are proposed: Nearctic: Elathous huguenini (Van Dyke, 1932) new combination; Gambrinus angulatus (Motschulsky, 1859) new combination; Gambrinus bicolor (Van Dyke, 1932) new combination; Gambrinus clypeatus (Motschulsky, 1859) new combination; Gambrinus confusus (LeConte, 1853) new combination; Gambrinus cribriceps (Van Dyke, 1943) new combination; Gambrinus crotchii (Horn, 1872) new combination; Gambrinus flavomarginatus (Knull, 1938) new combination; Gambrinus fulvipilis (Candèze, 1860) new combination; Gambrinus griseus (Beauvois, 1805) new combination; Gambrinus humidus (Lane, 1941) new combination; Gambrinus interstitialis (Melsheimer, 1846) new combination; Gambrinus lanchesteri (Lane, 1941) new combination; Gambrinus meridianus (Knull, 1947) new combination; Gambrinus mirus (LeConte, 1853) new combination; Gambrinus norahae (Al Dhafer, 2009) new combination; Gambrinus olentangyi (Knull, 1947) new combination; Gambrinus plebejus (Say, 1825) new combination; Gambrinus propexus (Candèze, 1860) new combination; Gambrinus rudis (Brown, 1933) new combination; Gambrinus rufihumeralis (Lane, 1941) new combination; Gambrinus seminudus (Van Dyke, 1932) new combination; Gambrinus shircki (Lane, 1965) new combination; Gambrinus sinuifrons (Fall, 1907) new combination; Gambrinus snakensis (Lane, 1965) new combination; Gambrinus stigma (Herbst, 1806) new combination; Gambrinus pictus (Van Dyke, 1932) new combination; Gambrinus ulkei (Horn, 1871) new combination; Gambrinus ursinus (Van Dyke, 1932) new combination; Gambrinus venablesi (Wickham, 1913) new combination; Limonius brevis (Van Dyke, 1932) new combination; Limonius sordidus (Van Dyke, 1932) new combination; Pheletes lecontei (Lane, 1971) new combination; Tetralimonius definitus (Ziegler, 1845) new combination; Tetralimonius humeralis (Candèze, 1860) new combination; Tetralimonius maculicollis (Motschulsky, 1860) new combination; Tetralimonius nimbatus (Say, 1825) new combination; Tetralimonius ornatulus (LeConte, 1857) new combination. Palearctic: Gambrinus elegans (Buysson, 1891) new combination; Gambrinus gibbosus (Platia and Gudenzi, 2006) new combination. Gambrinus henanensis (Schimmel, 2006) new combination; Gambrinus hinakurai (Kishii, 1998) new combination; Gambrinus katoi (Kishii, 2002) new combination; Gambrinus kawaharai (Kishii, 2002) new combination; Gambrinus kucerai (Schimmel, 2006) new combination; Gambrinus nanshanensis (Arimoto and Hiramatsu, 2013) new combination; Gambrinus naomii (Kishii, 1997) new combination; Gambrinus shaanxiensis (Schimmel, 2006) new combination; Gambrinus suturalis (Gebler, 1844) new combination; Gambrinus takabai (Kishii, 1997) new combination; Gambrinus violaceus (Müller, 1821) new combination; Gambrinus wittmeri (Chassain, 1998) new combination; Gambrinus yamato (Kishii, 1998) new combination; Gambrinus yujii (Arimoto, 2013) new combination; Gambrinus zhejiangensis (Schimmel, 2015) new combination; Limonius brancuccii (Schimmel and Platia, 1991) new combination; Limonius decorus (Gurjeva, 1975) new combination; Limonius exiguus (Schimmel and Platia, 1991) new combination; Limonius hartmanni (Schimmel, 1998) new combination; Limonius hiermeieri (Schimmel and Platia, 1991) new combination; Limonius hirtus (Dolin, 1978) new combination; Limonius hubeiensis (Kishii and Jiang, 1996) new combination; Limonius kubani (Schimmel, 1996) new combination; Limonius loebli (Schimmel and Platia, 1991) new combination; Limonius longicornis (Schimmel and Platia, 1991) new combination; Limonius macedonicus (Cate and Platia, 1989) new combination; Limonius marginellus brusteli (Leseigneur, 2004) new combination; Limonius manaliensis (Schimmel and Platia, 1991) new combination; Limonius miandamensis (Schimmel and Platia, 1991) new combination; Limonius minusculus (Schimmel and Platia, 1991) new combination; Limonius nigronitidus (Han and Lee, 2012) new combination; Limonius platiai (Mertlik, 1996) new combination; Limonius pseudopilosus (Platia and Gudenzi 1985) new combination; Limonius recticornis (Schimmel and Platia, 1991) new combination; Limonius riesei (Platia, 1988) new combination; Limonius rusticus (Schimmel and Platia, 1991) new combination; Limonius schurmanni (Platia and Gudenzi, 1998) new combination; Limonius sinensis (Schimmel and Platia, 1994) new combination; Limonius singularis (Schimmeland Platia, 1991) new combination; Limonius stapfi (Schimmel, 2007) new combination; Limonius turcicus (Platia, 2004) new combination; Limonius wittmeri (Schimmel and Platia, 1991) new combination; Tetralimonius quercus (Olivier, 1790) new combination; Tetralimonius reitteri (Gurjeva, 1976) new combination. The following 12 North American species are removed from synonymy and recognized as valid species: Gambrinus interstitialis (Melsheimer, 1846) status resurrected; Gambrinus propexus (Candèze, 1860) status resurrected; Gambrinus shircki (Lane, 1965) status resurrected; Gambrinus snakensis (Lane, 1965) status resurrected; Gambrinus ulkei (Horn, 1871) status resurrected; Limonius anceps LeConte, 1853 status resurrected; Limonius dubitans LeConte, 1853 status resurrected; Limonius infuscatus Motschulsky, 1859 status resurrected; Limonius pilosulus Candèze, 1891 status resurrected; Limonis semianeus LeConte, 1853 status resurrected. Tetralimonius humeralis (Candèze, 1860) status resurrected; Tetralimonius maculicollis (Motschulsky, 1860) status resurrected. New replacement names are proposed for three homynyms: Limonius schimmeli Etzler new name for Neoathousius ferrugineus Schimmel and Platia, 1991; Elathous malatyanus Etzler new name for Elathous bicolor Platia, 2010, not Elathous bicolor (LeConte, 1853); and Microdesmes carteri Etzler new name for Limonius angulatus Carter, 1939 (= Microdesmes angulatus). Limonius kondratieffi Al Dhafer, 2009 is a new synonymy of Elathous bicolor (LeConte, 1853). A key to genera, generic descriptions, notes on species, and definitions of important characters are provided.

A review of the genus Anelastes Kirby, 1819 (Coleoptera: Eucnemidae) of the Palaearctic fauna.

The genus Anelastes Kirby, 1819 of the Palaearctic fauna is revised. An amended diagnosis of the genus is elaborated. Two new species from North Africa, Anelastes abbreviatus sp. nov. and A. alius sp. nov. are described. Anelastes barbarus P.H. Lucas, 1846 and A. crenulatus (Bonvouloir, 1875) are redescribed and the lectotypes of both species are designated. A key to the Palaearctic species is provided. Anelastes barbarus is newly recorded from Uzbekistan.

Elateridae (Coleoptera) of Lebanon.

A checklist of Elateridae of Lebanon is provided. Altogether, 54 species classified in 23 genera are listed, with 11 species reported from the country for the first time. Elathous agilis sp. nov. and Megathous tannourinensis sp. nov. are described, compared with congeners, and their main diagnostic characters are figured.

Congruence Between Molecular Data and Morphology: Phylogenetic Position of Senodoniini (Coleoptera: Elateridae).

Senodoniini is a small lineage of click beetles currently comprising 21 species in two genera, distributed in the Himalayas and East and Southeast Asia. The definition and limits of this group have changed considerably during its history. Recent authors treat Senodoniini as a tribe within Dendrometrinae, usually close to Dimini, but this placement has never been rigorously tested. Here, we shed new light on the systematic position and limits of Senodoniini by performing a combined phylogenetic analysis of two nuclear and two mitochondrial molecular markers. Our results recovered Senodoniini not monophyletic, and placed them into the Lissominae complex, where they formed a clade with Austrelater Calder & Lawrence (Protelaterini). Molecular phylogeny is in agreement with the adult morphology. Additionally, we examined the morphology of a monotypic genus Rostricephalus Fleutiaux from Southeast Asia, which was previously classified in various Elateridae groups including Senodoniini, and its position was always uncertain. This genus shares morphological characters with Protelaterini. We provide morphological redescriptions as well as the figures of main diagnostic characters for Senodonia Laporte, Sossor Candèze, and Rostricephalus. Based on our results, we place these genera to Lissominae: Protelaterini, and hence synonymize Senodoniini Schenkling with Protelaterini Schwarz.

Latching of the click beetle (Coleoptera: Elateridae) thoracic hinge enabled by the morphology and mechanics of conformal structures.

Elaterid beetles have evolved to 'click' their bodies in a unique maneuver. When this maneuver is initiated from a stationary position on a solid substrate, it results in a jump not carried out by the traditional means of jointed appendages (i.e. legs). Elaterid beetles belong to a group of organisms that amplify muscle power through morphology to produce extremely fast movements. Elaterids achieve power amplifications through a hinge situated in the thoracic region. The actuating components of the hinge are a peg and mesosternal lip, two conformal parts that latch to keep the body in a brace position until their release, the 'click', that is the fast launch maneuver. Although prior studies have identified this mechanism, they were focused on the ballistics of the launched body or limited to a single species. In this work, we identify specific morphological details of the hinges of four click beetle species - Alaus oculatus, Parallelostethus attenuatus, Lacon discoideus and Melanotus spp. - which vary in overall length from 11.3 to 38.8 mm. Measurements from environmental scanning electron microscopy (ESEM) and computerized tomography (CT) were combined to provide comparative structural information on both exterior and interior features of the peg and mesosternal lip. Specifically, ESEM and CT reveal the morphology of the peg, which is modeled as an Euler-Bernoulli beam. In the model, the externally applied force is estimated using a micromechanical experiment. The equivalent stiffness, defined as the ratio between the applied force and the peg tip deflection, is estimated for all four species. The estimated peg tip deformation indicates that, under the applied forces, the peg is able to maintain the braced position of the hinge. This work comprehensively describes the critical function of the hinge anatomy through an integration of specific anatomical architecture and engineering mechanics for the first time.