Beetle Subfamily Research Articles

Immature stages and biology of the enigmatic oxyporine rove beetles, with new data on Oxyporus larvae from the Russian Far East (Coleoptera: Staphylinidae)

Oxyporinae are a visually attractive and highly specialized mycophagous subfamily of rove beetles (Staphylinidae) with enigmatic origins and a largely unknown evolutionary history. Our knowledge of their immature stages and biology, valuable for solving questions about their phylogeny, is still very fragmentary. Here, we describe for the first time the larval morphology of Oxyporus (s. str.) procerus Kraatz, 1879 and O. (Pseudoxyporus) melanocephalus Kirschenblatt, 1938, both from the Russian Far East. We redescribe the larval morphology of the widespread O. (s. str.) maxillosus Fabricius, 1775 based on material, also from the Russian Far East. All larvae are identified based on the combined evidence from rearing and cox1 barcoding. For O. maxillosus, O. procerus and O. (P.) melanocephalus we provide some new field and laboratory-based data on feeding, mating, oviposition, female brood care, duration of larval development, and behavior. We applied the Atheta-based system of Ashe & Watrous (1984) to describe and compare the chaetotaxy of these Oxyporus larvae. We extract the most essential comparable data for all species of Oxyporus with known larvae from poorly compatible published larval descriptions with dubious homology assessments for their chaetotaxy. In addition, data on fungal hosts and beetle biology is summarized for the genus and provided for each species. New morphological traits are revealed for the Oxyporus larvae. Significant differences in larval morphology, reproduction behavior and cox1 barcoding region between the subgenera Oxyporus s. str. and Pseudoxyporus Nakane & Sawada, 1956 correspond to the morphological distance between their adults and suggest that they may be potentially elevated to genus rank.

New species of karst-dwelling Pselaphinae from southwestern China (Coleoptera: Staphylinidae)

Three cavernicolous species of the ant-loving beetle subfamily Pselaphinae are described based on the material collected in the dark zone of limestone caves in southwestern China. Batraxis liyunchuni sp. nov. and Nipponobythus alienoceps sp. nov. from Guizhou are the first and third cave-dwelling species of their respective genus, but they do not exhibit particular troglomorphy compared to epigean congeners. Zopherobatrus lusciosus sp. nov. from Chongqing, showing typical morphological adaptation to hypogeal lifestyle, is the second known representative of this obligate cavernicolous genus. In light of the discovery of a second species, the generic diagnosis of Zopherobatrus is modified accordingly.

<p><strong><em>Scydmaenus linqibini</em></strong><strong> sp. nov., a new fossil Scydmaenini<em> </em>in mid-Cretaceous amber from northern Myanmar (Coleoptera: Staphylinidae: Scydmaeninae)</strong></p>

The tribe Scydmaenini is the second most diverse group of the ant-like stone beetle subfamily Scydmaeninae, with more than 730 extant species classified in seven extant genera (Newton, 2019). However, confirmed fossil records important for elucidating the evolutionary history of the tribe are extremely rare, represented by only two species previously reported from mid-Cretaceous Myanmar amber (Yin et al., 2018; Yin & Cai, 2019). Provided in this paper is the description of a third fossil species of Scydmaenini, again from Burmese amber, which sheds new light on the palaeodiversity and morphological disparity of this group during its early evolutionary stage.

Generic Review of New Zealand Chrysomelinae (Coleoptera: Chrysomelidae).

The leaf beetle subfamily Chrysomelinae is reviewed for New Zealand. The native fauna consists of six genera, three new, all of which are described: Aphilon Sharp, 1876; Caccomolpus Sharp, 1886; Chalcolampra Blanchard, 1853; Mauroda gen. nov.; Nanomela gen. nov.; Zeaphilon gen. nov.. Chalcolampra is the senior synonym of Cyrtonogetus Broun, 1915 (comb. nov.). These genera include 51 species, nine newly described and eight in new combinations, as follows: Caccomolpus laticollis (Broun, 1893) comb. nov., from Aphilon; C. pretiosus (Broun, 1880) comb. nov., from Aphilon; Chalcolampra crassa (Broun, 1915) comb. nov., from Cyrtonogetus; Maurodus arcus sp. nov.; M. cinctiger (Broun, 1921) comb. nov., from Caccomolpus; M. impressus (Broun, 1914) comb. nov., from Aphilon; M. lepidus sp. nov.; M. maculatus (Broun, 1893) comb. nov., from Caccomolpus; M. nunni sp. nov.; M. occiduus sp. nov.; M. ornatus (Broun, 1910) comb. nov., from Caccomolpus; M. owenensis sp. nov.; M. plagiatus (Sharp, 1886) comb. nov., from Caccomolpus; M. supernus sp. nov.; Nanomela tiniheke sp. nov.; Zeaphilon marskeae sp. nov.; Z. mirandum sp. nov.. All 11 species in the genus Maurodus are described and a key given for their identification. Type material of the New Zealand species of Aphilon (10 species), Caccomolpus (14 species) and Chalcolampra (13 species) is reviewed and lectotypes designated for 16 species, as well as M. cinctiger. A type species is designated for Caccomolpus: C. globosus Sharp, 1886. Holotypes are confirmed for 26 species. Seven genera and 13 species of exotic Chrysomelinae also occur in New Zealand and their presence is briefly reviewed. One of these exotics has been misnamed as Paropsisterna variicollis (Chapuis, 1877), a junior synonym of P. cloelia (Stål, 1860) (syn. nov.). A key to all genera of Chrysomelinae in New Zealand is provided.

The first fossil record of the rove beetle subfamily Protopselaphinae (Coleoptera: Staphylinidae) from mid-Cretaceous Burmese amber

Protopselaphinae is a small rove beetle subfamily endemic to southeast Asia with only eight extant species placed into a single genus. Here we describe and illustrate the first fossil representative of Protopselaphinae, Protopselaphus thayerae sp. nov., from mid-Cretaceous Burmese amber (Albian-Cenomanian). The new species is distinguished from all extant taxa of Protopselaphus by having tarsomeres 1 and 2 not subequal in length and mentum with a shallow emargination. The new fossils provide evidence of an ancient origin of Protopselaphinae, a ‘missing link’ between the megadiverse Pselaphinae and other subfamilies in the Omaliine group. Protopselaphus thayerae sp. nov. is a testament to an extreme morphological and probably also ecological stasis in Protopselaphinae over the last 99 million years.

Molecular phylogenetic assessment of the tribal classification of Lamiinae (Coleoptera: Cerambycidae)

Lamiinae is the most diverse subfamily of longhorned beetles, with about 20,000 described species classified into 80 tribes. Most of the tribes of Lamiinae were proposed during the 19th century and the suprageneric classification of the subfamily has never been assessed under phylogenetic criteria. In this study, we present the first tribal-level phylogeny of Lamiinae, inferred from 130 terminals (representing 46 tribes, prioritizing generic type species of the tribes) and fragments of two mitochondrial and three nuclear markers (cox1, rrnL, Wg, CPS and LSU; 5,024 aligned positions in total). Analyses were performed under Maximum Likelihood and Bayesian methods based on two datasets: a dataset including all taxa available for the study, and a reduced dataset with 111 terminals where taxa only contributing with mitochondrial markers were excluded from the matrix. The monophyly of Lamiinae was corroborated in three of the four analyses and 11 of the 35 tribes with more than one species represented in the analyses were consistently recovered as monophyletic. However, 15 tribes were not retrieved as monophyletic, requiring a revision of their boundaries: Acanthocinini, Acanthoderini, Agapanthiini, Apomecynini, Desmiphorini, Dorcaschematini, Enicodini, Hemilophini, Monochamini, Onciderini, Parmenini, Phytoeciini, Pogonocherini, Pteropliini and Saperdini. Based on these results, when strong support values for paraphyly were recovered, we argue a number of tribe synonymies, including Moneilemini as synonym of Acanthocinini; Onocephalini of Onciderini; Dorcadionini, Gnomini, Monochamini and Rhodopinini of Lamiini; and Obereini and Phytoeciini of Saperdini. Other taxonomic changes proposed in this study based on the criterion of monophyly and supported by morphological characters include the transfer of Tricondyloides and Stenellipsis to Enicodini, and of Dylobolus stat. rest., which is removed as subgenus of Mecas and restituted as genus, to Hemilophini. Furthermore, our analyses suggest that Ostedes and Neohoplonotus should be removed from Acanthocinini and Parmenini, respectively, and Colobotheini should be redefined to encompass several genera currently placed in Acanthocinini.

Baltic amber members of the extant Micrillus–Scymbalium lineage of the Paederinae rove beetles (Coleoptera, Staphylinidae) and their systematic and ecological significance

Paederinae, a diverse subfamily of rove beetles (Staphylinidae), is poorly explored with an outdated subtribal and generic classification lacking proper phylogenetic perspective. Therefore, the discovery of two Baltic amber fossil specimens resembling the genera Micrillus and Scymbalium, which are particularly challenging in terms of systematics, called for a thorough analysis to infer their phylogenetic position and their ecological requirements. The fossils were examined with light microscopy supplemented by X-ray micro-computed tomography, and then scored into a Paederinae-specific matrix of 99 morphological characters, along with a broad sample of recent Paederinae and non-paederine outgroups. Morphological phylogenetic analyses were conducted, using Bayesian Inference and Maximum Parsimony. The obtained phylogeny confirmed that the genera Scymbalium and Micrillus form a lineage outside Lathrobiina; therefore, both genera are now classified as Lathrobiini incertae sedis pending a more inclusive phylogenetic work on Paederinae. The analysis firmly placed both fossils in that recent lineage, albeit rendering Micrillus paraphyletic with respect to Scymbalium. Without a more extensive analysis based on the revised world fauna, any systematic changes would be premature. Thus, the fossils are described as Micrillus electrus, sp. nov. and Scymbalium phaethoni, sp. nov. in accordance with the current diagnoses of both genera. Given that the recent species of Micrillus and Scymbalium are predominantly thermophilic and mainly confined to dry open landscapes in Africa, southern Eurasia and Australia, the finding of Baltic amber representatives implies the very diverse landscape and the equable (sub)tropical palaeoclimatic conditions of the Eocene amberiferous ‘forest’, the latter being the subject of continued debates.

Multigene phylogeny uncovers oviposition-related evolutionary history of Cerambycinae (Coleoptera: Cerambycidae)

The correlated evolution of the morphology of reproduction-related organs and biological aspects of insects is intriguing yet poorly understood. As one of the largest subfamilies of phytophagous beetles, Cerambycinae provides a unique opportunity to study this topic because of the wide range of host plants, oviposition strategies, and various forms of ovipositors of its members. Nevertheless, the evolutionary pathway of these traits is unexplored and no robust phylogenetic study of the subfamily has been conducted. In this study, we reconstructed a first multi-locus phylogeny of Cerambycinae representing a wide range of oviposition strategies, host plants, and ovipositor lengths. Ancestral state reconstruction analyses showed that the shortened ovipositor in Cerambycinae evolved at least four times independently and that the use of host plant has evolved from stressed hosts to dead or living hosts and from broad-leaved trees to conifers. The correlated evolution test revealed the correlation between ovipositor length and oviposition strategy. Our study elucidates for the first time the complex evolutionary history of the ovipositor, oviposition strategy, and host plant usage, and their correlations within Cerambycinae.

Pseudotelegeusis meloi sp. nov., the first Telegeusinae from Peru (Coleoptera: Omethidae, Telegeusinae)

Telegeusinae is a small subfamily of Elateroid beetles presently attached to the Omethidae family. Pseudotelegeusis Wittmer, 1976 is composed of three species, two occurring in northern South America and one in Mexico. Here we describe the fourth species for the genus, Pseudotelegeusis meloi sp. nov., collected in a Malaise sample from the region of Madre de Dios, Peru. The new species is diagnosed mainly by the antennae serrate from antennomeres III to X, eyes occupying half of head width in lateral view and vertex occupying 3/5 of head in dorsal view. This new species is close to the other two South American species, P. howdeni Wittmer, 1976 and P. oculatus Wittmer, 1976, according to the serrate antennae and number of ventrites. The three South American species differ from the Mexican species, P. jiliotupaensis Zaragoza-Caballero, 2008, by the different antennae and the number of ventrites, which indicates that the Mexican species should possibly be classified in a different genus. The main morphological characters, including maxillar palpi, tentorial pits and male genitalia, are illustrated, and an updated key to the species of Pseudotelegeusis is given, as well as distribution maps.

Congruence of morphological and molecular phylogenies of the rove beetle subfamily Staphylininae (Coleoptera: Staphylinidae)

Staphylininae is the third largest subfamily of the enormous family Staphylinidae. Monophyly of Staphylininae and its sister relationship to the subfamily Paederinae have been broadly accepted according to both conventional morphology- and molecular-based phylogenies until the last three years. Recent molecular phylogenies rejected monophyly of Staphylininae and regarded Paederinae as a clade within it. This paper re-evaluates the recent molecular work, aiming to clarify the relationship between Staphylininae and Paederinae and resolve intertribal relationships within Staphylininae. Based on a new six-gene data set (5707 bp) for 92 taxa including Oxyporinae (outgroup), representatives of Paederinae, and members of all extant tribes of Staphylininae from published DNA data in GenBank, we generated a well-resolved phylogeny of Staphylininae with all deep nodes (intertribal relationships) strongly supported, and reassert the hypothesis that Staphylininae is monophyletic and indeed the sister group to Paederinae using both Bayesian and maximum likelihood inference. Additionally, our study is a case-study to show that both outgroup selection and completeness of nucleotide data can influence the outcome of a molecular phylogeny. With an increasing number of staphylinid fossils being discovered, the robust phylogeny of Staphylininae inferred by our research will provide a good framework for understanding the early evolution of this group.

THz tomography for detecting damages on wood caused by insects

Annually, wood-destroying insects cause severe damage in forests. The widespread population of typographer (Ips typographus), a beetle species from the subfamily of bark beetles (Scolytidae) in Europe, mainly occurs in coniferous wood, especially in spruce (Picea abies), the most silviculturally relevant wood species. The typographer infestation is detected mainly by visual monitoring and without invasive techniques only recognizable at a late stage. Terahertz radiation has shown enormous potential in nondestructive testing. THz measurements in the time-domain performed with a robotic THz system can be used for 3D reconstruction of the internal structure of the samples. In this article, we report the detection of a change in the wood structure of spruce caused by typographer burrows.

A new subfamily of hide beetles from the Cretaceous of northern Myanmar (Coleoptera: Scarabaeoidea: Trogidae)

ABSTRACT With four genera and some 330 extant species, the Trogidae are a small group of scarabaeoid beetles that feed on hard keratinous tissue. Here, the first hide beetle from mid-Cretaceous Burmese amber, Kresnikus beynoni gen. et sp. nov., is described and illustrated, representing the first trogid preserved in fossilised resin. A new subfamily, Kresnikinae subfam. nov., is erected for the unusual species, characterised by frons and clypeus completely fused, a deflexed anteromedial portion of the frontoclypeal region, clypeus with a straight anterior margin, subtriangular scutellum, pronotum and elytra with simple setae, mesocoxal cavities separated by a rounded metaventrite process, metatibial spurs as long as the first metatarsal segment, and metatarsi sparsely pubescent. Kresnikus beynoni gen. et sp. nov. shows several seemingly ancestral characters including separated mesocoxae and small body size, hinting at a Gondwanian origin of hide beetles. The fossil record of the family Trogidae is reviewed and an annotated checklist of fossil taxa is provided.

Total‐evidence approach reveals an extinct lineage of Paederinae rove beetles from Cretaceous Burmese amber

AbstractThe fossil record contains vital information about the evolution of lineages and is a source of data that cannot be reconciled other than by the direct observation of morphologies. Total‐evidence phylogenetic reconstruction is being increasingly used to assess the position of extinct taxa by incorporating morphological data from extinct and extant taxa together with molecular data from extant taxa in a united framework. Here we apply the method to two Cretaceous Burmese amber inclusions belonging to the rove beetle subfamily Paederinae. To perform the total evidence analysis, we constructed the first morphological matrix and the most comprehensive molecular dataset for the subfamily. Our analysis reveals an extinct lineage of Paederinae rove beetles with a suite of unique morphological characters, resulting in the description of a new genus: Diminudon gen. nov. and two new species: D. schomannae sp. nov. and D. kachinensis sp. nov. Simultaneously our analyses provide new insights into the evolution and classification of the entire subfamily. We also discuss the unusually small size of the newly described Paederinae, which may represent an additional case for miniaturization in the Cretaceous.

Three additional new genera of acidocerine water scavenger beetles from the Guiana and Brazilian Shield regions of South America (Coleoptera, Hydrophilidae, Acidocerinae).

Recent study of the water scavenger beetle subfamily Acidocerinae in the Neotropical region has uncovered numerous undescribed species that are not able to be placed in existing genera. Here, we describe three new genera to accommodate 17 of these new species from South America: Aulonocharesgen. nov. for Aulonochareslingulatussp. nov. (French Guiana, Suriname), Aulonocharesnovoairensissp. nov. (Brazil), and Aulonocharestubulussp. nov. (Brazil, Guyana, Suriname, Venezuela); Ephydrolithusgen. nov. for Ephydrolithushamadaesp. nov. (Brazil), Ephydrolithusminorsp. nov. (Brazil), Ephydrolithusogmossp. nov. (Brazil), Ephydrolithusspiculatussp. nov. (Brazil), and Ephydrolithustelisp. nov. (Brazil); and Primocerusgen. nov. for Primoceruscuspidissp. nov. (Venezuela), Primocerusgigassp. nov. (Venezuela), Primocerusneutrumsp. nov. (Guyana, Suriname, Venezuela), Primocerusocellatussp. nov. (Venezuela), Primoceruspetilussp. nov. (Brazil), Primoceruspijiguaensesp. nov. (Venezuela), Primocerusmaipuresp. nov. (Venezuela), Primocerussemipubescenssp. nov. (Guyana), and Primocerusstriatolatussp. nov. (Suriname). The genus Ephydrolithusgen. nov. is currently known to be restricted to seepages in the mountainous regions of the Brazilian Shield. Aulonocharesgen. nov. and Primocerusgen. nov. are both currently only known from the Guiana Shield, though widespread in that region where they are associated with streams and seeps. We present differential diagnoses, maps, habitat details, and illustrations of all new genera and species here described.

Defining new dung beetle tribes to resolve discrepancies between phylogeny and tribal classification in the subfamily Scarabaeinae (Coleoptera: Scarabaeidae).

The monophyletic, dung beetle subfamily, Scarabaeinae, has a long history of subdivision into tribes and subtribes represented by groups of genera unified by designated characters. Various tribal names have been proposed although only 11 or 12 were considered valid in recent reviews. Three of these 12 tribes have now been invalidated due to extensive polyphyly indicated by both morphological and molecular phylogenies. Although partial revision of tribal classification was proposed in the most recent global molecular phylogeny of the subfamily, this was primarily limited to redefinition of membership or provision of support for pre-existing tribes. Complete revision was not attempted as the phylogeny examined interrelationships between only ~52% of the valid described genera. It was also hampered by inconsistencies in topology using different analytical methods, weakened by limited bootstrap support for many basal nodes, as well predicting several phylogenetic relationships that seemed anomalous with regards to biogeographical hypotheses. Nevertheless, using this phylogeny, we propose further revision of tribal classification in a clade of primarily African genera included within a group defined as "basal Scarabaeinae". Using three different methods, the sister lineages of this clade were consistently recovered, mostly with strong bootstrap support for their molecular relatedness. Therefore, we provide a number of defining morphological characters to support their proposed designation as three new tribes: Byrrhidiini, Endroedyolini and Odontolomini. We also discuss approaches to a full tribal revision as well as the implications for historical biogeography of the Scarabaeinae.

Morphology of the third instar larva of Colobopterus quadratus (Coleoptera: Scarabaeidae: Aphodiinae) using scanning electron microscopy.

Aphodiinae are a large cosmopolitan subfamily of Scarab beetles (Scarabaeoidea: Scarabaeidae), playing an important role during dung decomposition. Many aspects, especially immature stages, of these dung beetles have not yet been recorded due to their comparative small body sizes and lacking of striking rolling behavior. In this study, the third instar larva of Colobopterus quadratus is morphologically described using scanning electron microscopy. The larva is atypical for the combination of following morphological features: (a) the larval antennae are five-segmented; (b) the clypeus bears 4 minute protuberances on dorsal surface; (c) the epitorma on epipharynx is ventrally protuberant; (d) the scissorial area of left mandible is broad and blade-like; (e) the raster is furnished with six glabrous protuberances and two rows of pali arranged in V-shape. Some significant ultra-morphological features were discovered in larval Aphodiinae for the first time. The presence of blade-like incisor on the left mandible implies the potential root cutting ability.

Associations between Fossil Beetles and Other Organisms

The present work reveals plant and animal associates of 16 families and subfamilies of fossil beetles that have been preserved in amber from Mexico, the Dominican Republic, and Myanmar. The associates include mites, pseudoscorpions, spiders, insect parasites and predators, fungi, angiosperm parts, vertebrates, and nematodes. The presence of these fossil associates can be attributed to the rapid preservation of organisms in resin, thus maintaining natural associations almost “in situ”. Examples of present-day associations similar to those of the fossils show that specific behavioral patterns are often far more ancient than the specific lineages involved.

(S)-Sulcatol Is a Pheromone Component for Two Species of Cerambycid Beetles in the Subfamily Lamiinae.

Males of several species in the large cerambycid beetle subfamily Lamiine, native to South and North America, are known to produce aggregation-sex pheromones composed of three related structures: the sesquiterpene catabolic product geranylacetone, its corresponding alcohol (known as fuscumol), and the acetate ester of the alcohol (fuscumol acetate). Here, we show that males of two lamiine species native to the eastern USA, Astylopsis macula (Say) and Leptostylus transversus (Gyllenhal) (both tribe Acanthocinini), produce pheromones composed of the structurally related (S)-6-methylhept-5-en-2-ol ([S]-sulcatol). Males of both species also produced 6-methylhept-5-en-2-one (sulcatone), and males of A. macula produced trace amounts of (R)-fuscumol acetate. Field experiments demonstrated that both species were attracted by (S)-sulcatol. Sulcatone was not attractive as a single component, nor did it influence attraction of A. macula to (S)-sulcatol, while its effect on L. transversus was unclear. Data from the field experiments, and a separate experiment using traps fitted with a timer mechanism that rotated trap jars, revealed that the two species overlap only slightly in both seasonal and daily flight period, thus minimizing interspecific attraction. Racemic fuscumol acetate and fuscumol antagonized attraction of both species to sulcatol. The identification of sulcatol as a cerambycid pheromone extends the known range of pheromone components in the subfamily Lamiinae.

The ant nest “bomber”: Explosive defensive system of the flanged bombardier beetle Paussus favieri (Coleoptera, Carabidae)

Bombardier beetles are famous for their unique ability to explosively discharge hot quinones from their pygidial glands when threatened. Here we provide the first detailed description of the ultrastructure of the defensive gland system of the genus Paussus, the most speciose genus in the ground beetle subfamily Paussinae. Paussine beetles are commonly known as “flanged bombardier beetles” due to the presence of a flange on their elytra that assists in directing their defensive chemicals toward the front of their bodies. In this paper, we use optical, fluorescence and focused ion beam (FIB/SEM) microscopy to analyse and illustrate anatomy and ultrastructure of the explosive defensive system of Paussus favieri, a charismatic myrmecophilous species. The defensive system of this species consists of two independent, symmetrical glands each composed of secretory lobes, a long collecting duct, a bilobed reservoir chamber, a cuticular valve, a sclerotized reaction chamber, and an accessory chamber, associated with the reaction chamber, that is surrounded by several isolated glandular cells. Differences between the pygidial defensive systems of Paussus favieri and those of Brachininae are discussed.

New Taxa of Phrenapatinae (Coleoptera: Tenebrionidae) from Southern Africa, with New Distributional Data and a Checklist of the Afrotropical Fauna

New data on the little-studied darkling beetle subfamily Phrenapatinae is given for the Afrotropical Region. The following new taxa are described and included into a key to the Phrenapatinae species of southern Africa: Archaeoglenes ruthmuelleraesp. nov. from the Republic of South Africa and the Republic of Mozambique, Endroeditagalusgen. nov.ongoyussp. nov. from the Republic of South Africa and Endroeditagalusgen. nov.ntsubanussp. nov. from the Republic of South Africa. New distributional data is incorporated into a checklist of the Afrotropical Phrenapatinae fauna.