Antennal Club Research Articles

A new species of the extant genus Bulasconotus from mid-Cretaceous Kachin amber (Coleoptera: Zopheridae: Colydiinae)

A fossil species of the extant colydiine genus Bulasconotus Ślipiński & Lawrence, B. carinisternus Li, Ślipiński & Cai sp. nov., is reported from mid-Cretaceous Kachin amber of northern Myanmar. The new species shares with extant Bulasconotus the 3-segmented antennal club, externally open procoxal cavities, and similar sculpture on the pronotum and elytra, but could be recognized by the medially carinated prosternal process. The present discovery provides a valuable example of morphological stasis in the cylindrical bark beetles.

The first Paleogene record of Hyperisus Mulsant and Rey (Coleoptera: Ptinidae) with description of a new species and an attempt of biogeographic analysis of ptinid assemblage in Baltic amber

ABSTRACT Based on an inclusion in Baltic amber, the first extinct species of the genus Hyperisus Mulsant and Rey, 1863 (Ptinidae: Ernobiinae: Xestobiini), namely H. carstengroehni sp. nov. is described. This new fossil Eocene species differs from extant European congeners in having the dorsal pubescence of two types; the lesser body size; the abdominal ventrite 5 punctate; the dorsal pubescence evenly dense; the antennal club longer than antennomeres 1–8 combined; and in the details of dorsal punctation. Provisional biogeographical affinities of the described Baltic amber Ptinidae (as of July 2023) are briefly analysed. All 20 extant genera known in Baltic amber (100% of analysed assemblage) still inhabit Holarctic of Recent. The ptinid assemblage of Baltic amber is almost twice closer in the composition of genera to the extant fauna of Palearctic or Nearctic than to other regions. Possible explanations are proposed for the abundance of death-watch beetles in Baltic amber.

New Species of Paussus, Subgenus Scaphipaussus (Coleoptera: Carabidae: Paussinae), from Southeast Asia Reveal Ambiguities in Species Group Limits and High Species Diversity in the Oriental Region.

Paussus, commonly known as ant nest beetles, is the most diverse genus of Paussinae (Coleoptera: Carabidae) with a very complex taxonomic history. Biodiversity research in Southeast and South Asia yields new species that can contribute to a better understanding of the morphological disparity and species-group or subgenus delimitation. Here, we describe nine new species from Southeast Asia and China: Paussus (Scaphipaussus) fencli sp. nov. (China), P. (S.) mawdsleyi sp. nov. (Borneo), P. (S.) bakeri sp. nov. (Philippines), P. (S.) jendeki sp. nov. (Laos), P. (S.) saueri sp. nov. (India), P. (S.) annamensis sp. nov. (Vietnam), P. (S.) phoupanensis sp. nov. (Laos, Vietnam), P. (S.) bilyi sp. nov. (Thailand), and P. (S.) haucki sp. nov. (Thailand). We also bring new data on P. (S.) corporaali Reichensperger, 1927 (Java) and P. (S.) madurensis Wasmann, 1913 (India). Besides formal descriptions, we provide photographs of the habitus in the dorsal and dorsolateral view, antennal club, head crest, and male genitalia if the male is available. Based on the comparison of new and earlier described species, we show that the antennae are highly diverse within the Scaphipaussus. Considering other characters, some species are placed in Scaphipaussus, but they differ from putative relatives in the antennal morphology. The presence of the frontal protuberances and crests is a more reliable character. Additional species show that Scaphipaussus is most diverse in southeastern Asia, especially in Indo-Burma. Concerning its supposed late Miocene origin, the group underwent rapid radiation. The species diversity of Scaphipaussus almost doubled in the last decade, and it is highly probable that further species will be described in the future.

An exceptional new weevil genus and species (Coleoptera: Curculionidae) from Tanzania

The new genus Borisius gen. nov. and the new species, Borisius korotyaevi sp. nov. are described and illustrated in the tribe Lixini from Tanzania in the Afrotropical region. The new genus can easily be recognized by the following combination of characters: antennal club greatly elongate and spindle-shaped, forehead with two prominent ridges triangularly diverging anteriad, pronotum constricted with two lateral projections, third elytral interstria strongly raised in basal fifth, humeri swollen, femora dentate.

Philcarneum new genus and Constricticollis new genus, two distinctive rhinoceros beetles (Coleoptera: Scarabaeidae: Dynastinae: Pentodontini) from opposite sides of Australia with a revised key to the Australian dynastine genera

Females of two unusual dynastines (Coleoptera: Scarabaeidae: Dynastinae: Pentodontini) from Australia are described and compared with other known Australian genera and species. Philcarneum aenigma Allsopp & Hutchinson new genus, new species from coastal southeastern New South Wales was recognised as novel in the 1980s, but has lacked a formal name, making it ‘invisible’ in the literature. It is placed in the Cheiroplatina. Constricticollis clunis Hutchinson & Allsopp new genus, new species recently captured near Kununurra, northern Western Australia is placed in the Pentodontina. Within the Dynastinae many important generic-level characters relate to mouthpart morphology, which are not sexually dimorphic, thus allowing to determine females to genera in absence of males, whose secondary sexual characters (obvious horns, claw modifications, antennal club length, etc.) are often used in keys. The key to Australian Dynastinae in Weir et al. (2019) is modified to accommodate these two genera and Erbmahcedius Hutchinson & Allsopp, 2021. Distributional maps and data on habitats are provided.

Two new riparian Pselaphinae from Hubei, Central China (Coleoptera: taphylinidae).

The Pselaphinae fauna of Hubei Province in central China is extremely poorly documented. Here we describe two new species recently collected at a riverbank near Chongyangs county seat. Batrisiella riparia sp. nov. is characterized by the greatly swollen metafemora of the male, and Nipponobythus varicornis sp. nov. has a darkish-colored body, and uniquely modified male antennal clubs and metaventrite. Illustrations of the habitus and taxonomically informative characters of both species are provided for a reliable identification.

Description of Euchre gen. nov., a new Coccidulini genus (Coleoptera: Coccinellidae) from the Euchre Valley in Australia

AbstractAustralia is inhabited by a very rich and mostly endemic fauna of ladybird beetles (Coccinellidae), with a relatively high proportion of taxa belonging to the tribe Coccidulini. Australian Coccidulini are grouped in 15 genera, of which 11 are endemic. Here, a new distinctive Australian Coccidulini genus and species is described—Euchre australis gen. et sp. nov., which is characterised by compact antennal club, long ventral antennal grooves on head capsule extending to anterior margin of prosternum, and presence of chin piece partially covering mouthparts in repose. Its relationship with other Australian Coccidulini genera is discussed.

The First Record of a Species of the Genus <i>Acicnemis</i> Fairmaire (Coleoptera: Curculionidae) in Miocene Sumatran Amber

A new species of the genus Acicnemis Fairmaire, 1849 is described from the early Miocene Sumatran amber. The new species, Acicnemis sumatranus sp. nov., differs from A. suturalis Roelofs, 1875 in the larger body size, a small antennal club, longer femora, and a large teeth on the metafemora. This is the first record of the tribe Acicnemidini in the Neogene and the first described beetle from Sumatran amber.

A new short-winged flower beetle with exaggerated head and antennal scape in mid-Cretaceous amber from northern Myanmar (Coleoptera: Kateretidae)

Kateretid beetles are known for loosely three-segmented antennal club, comparatively short elytra exposing abdominal segments, and their anthophylous-spermophagus biology likely originated since the Cretaceous period. Fossil kateretids from the Mesozoic are crucial for understanding the early evolution of morphological disparity and palaeoecology. Here, we establish Protokateretes gen. nov., a new genus of Kateretidae characterized by exaggerated expansion of scape in males. Eoceniretes antiquus Peris and Jelínek is transferred to Protokateretes, and a new kateretid beetle with large head, Protokateretes megacephalus sp. nov., is described and illustrated. Our discovery highlights the high morphological disparity of the currently small family in the Cretaceous.

Paussus (Edaphopaussus) asseyi sp. nov. (Coleoptera: Carabidae: Paussinae) from the Nguru Mountains of the Eastern African Arc in Tanzania

A new species of Paussus L., 1775 (Coleoptera: Carabidae) is described from the Nguru Mountains of the Eastern African Arc in Tanzania. Paussus asseyi sp. nov. is diagnosed by the shape of the antennal club, which bears two sharp edges at the outer margin, the blunt spines on tibiae, and the characteristic colouration that allows this species to be distinguished from all other species in Paussus (Series I) defined in the latest molecular phylogeny. Other characters, i.e., the shape of the pronotum and absent pronotal setae, place the new species in the subgenus Edaphopaussus Kolbe, 1920. The colouration resembles P. dichrous Janssens, 1950 from Democratic Republic Congo and Angola and some Asian species, yet all are morphologically different from the new species. The robust head, small eyes, and clypeus shape resemble distantly related P. (Hylotorus) cephalotes Raffray, 1886. The individual mountain massifs of Eastern Tanzania represent rainforest islands set in much drier lowlands with savannah ecosystems. The new species contributes to our understanding of the isolated mountain ranges' relatively poorly investigated beetle fauna.

Adalia decempunctata (Coleoptera: Coccinellidae), a Palaearctic species now established in North America

Abstract The Palaearctic ten-spotted lady beetle, Adalia decempunctata (Linnaeus), has been confirmed as established in North America, based on morphological characters and DNA barcodes. Its distribution currently appears limited to the Avalon Peninsula of the island of Newfoundland, Canada. Several characters, including the colour of the mesepimera, frons, labrum, antennal club, mouthparts, and legs, are reliable for discriminating among this species and the native, Holarctic two-spotted lady beetle, Adalia bipunctata (Linnaeus), in Newfoundland. An identification key to the two species is provided.

An enigmatic beetle with affinity to Lamingtoniidae in mid-Cretaceous amber from northern Myanmar (Coleoptera: Cucujoidea)

An enigmatic cucujiform beetle, Alloterocucus atratus Li, Leschen, Liu, and Cai gen. et sp. nov., is reported from mid-Cretaceous Burmese amber. The character combination of the new fossil is not completely consistent with any of the known cucujoid or erotyloid families. Based on our phylogenetic analyses, Alloterocucus is assigned to Cucujoidea and may be allied to Lamingtoniidae, which contains a single Australasian genus in the extant fauna. Alloterocucus shares with Lamingtoniidae a similar habitus and a series of characters, including the absence of postocular constriction, 3-segmented antennal club, externally open procoxal cavities, laterally open mesocoxal cavities, exposed pro- and mesotrochantins, and the absence of epipleural fovea and pronotal setose cavities, but differs from extant Lamingtoniidae in its apically truncate terminal maxillary palpomeres, 5-5-4 tarsi in male and absence of distinct dorsal punctation.Zoobank registration[https://zoobank.org/], identifier [111CE15E-5B49-4154-9E4A-7B3A738C6D2A].

Triplax sulphuricollis Reitter, 1887 from the Hyrcanian forests of Iran recognized as a valid species by morphology and barcoding (Coleoptera: Erotylidae)

The status of Triplax collaris sulphuricollis Reitter, 1887 is reevaluated based on recent records from the Hyrcanian forests in northern Iran. Morphological features and barcoding support separate species status as Triplax sulphuricollis Reitter, 1887, new status. Morphological characteristics include an orange-yellow antennal club and elytral punctation arranged in striae. Triplax sulphuricollis is associated with oyster fungi of the genus Pleurotus growing on dead wood of deciduous trees.

Taxonomy of 'Euconnus complex'. Part XXIV. Intermediate forms between Psomophus, Eupentarius and Euconnus s. str. in the East Palaearctic fauna unify problematic subgenera (Coleoptera, Staphylinidae, Scydmaeninae)

Within the West Palaearctic region, the subgenera Psomophus and Eupentarius can be easily distinguished from Euconnus s. str. based on the antennal, pronotal and male genital structures. However, in other regions, described and undescribed species of Euconnus can be found that show intermediate features between these three subgenera. This problem is analyzed based on fourteen exemplary species that occur in the East Palaearctic region, mainly in Japan. It is concluded that there are intermediate forms between a trimerous antennal club, previously treated as the primary diagnostic feature of Psomophus, and a tetramerous club, typical of most species placed in Eupentarius and Euconnus s. str. The shape of the pronotum, the median pronotal antebasal pit, and the bifurcate aedeagal apex, thought to be typical of Eupentarius, were also found to vary among apparently closely related species. Consequently, Psomophus syn. n. and Eupentarius syn. n. are placed as junior synonyms of Euconnus s. str. The following species are redescribed or described: (1) Euconnus callidus group: E. chinensis Franz (China: Fujian), E. multiinsularis sp. n. (Japan: C & N Ryūkyū); (2) species sola E. rectitibia sp. n. (Japan: Honshū, Kyūshū); (3) Euconnus kirin group: E. kirin sp. n. (Japan: Honshū), E. yaimanus sp. n. (Japan: S Ryūkyū), E. uchinaanchu sp. n. (Japan: C Ryūkyū); (4) Euconnus pseudotrimerus group: E. pseudotrimerus sp. n. (Japan: Honshū), E. urauchianus sp. n. (Japan: S Ryūkyū); (5) Euconnus taiwanus group: E. taiwanus Franz (Taiwan and newly recorded from Japan: S Ryūkyū), E. fukiensis Franz (China: Fujian), E. bibaculatus sp. n. (Japan: S Ryūkyū), E. cryptoiriomotensis sp. n. (Japan: S Ryūkyū), E. oitaensis sp. n. (Japan: Kyūshū), and E. banana sp. n. (Japan: C Ryūkyū). A synonymic checklist of subgenera of Euconnus and a preliminary illustrated key to subgenera are given.

A New Genus of Sap Beetles (Coleoptera: Nitidulidae) from Mid-Cretaceous Amber of Northern Myanmar.

Nitidulidae is the most diverse family of the recently recognized superfamily Nitiduliodea, but Mesozoic nitidulids that are critical for understanding their early diversification are sparse. Here, we report a new genus and species of Nitidulidae, Protonitidula neli gen. et sp. nov., that was recovered from mid-Cretaceous amber in northern Myanmar. The new genus is distinguished from all members of the extant nitidulid subfamilies most prominently by the loose antennal club and the absence of subantennal grooves. Protonitidula neli can be excluded from the closely related Kateretidae and classified into Nitidulidae by the broad and apically expanded prosternal process, although it has many pleisiomorphic characters.

Transitional morphology and Afrotropical affinity of a bythinoplectine rove beetle from the early Eocene of India (Coleoptera: Staphylinidae: Pselaphinae)

Recently discovered Ypresian-age amber from Cambay, India, reveals an ancient arthropod assemblage on the Indian subcontinent during its collision with Asia. Despite the tectonic history of India, limited connections have been found between the Cambay palaeofauna and present-day Madagascan and mainland African faunas. Here, I describe a new fossil pselaphine rove beetle (Staphylinidae: Pselaphinae) recovered from the Cambay deposit that shows closest apparent phylogenetic affinity to modern Afrotropical genera. Yprezethinus grimaldii gen. et sp. nov. is placed in Bythinoplectini, subtribe Bythinoplectina. Based on antennal and maxillary palp morphology, Yprezethinus is a putative transitional stem lineage of the Zethinus-group of genera—an extant clade distributed across equatorial African rainforests. Although Yprezethinus shares with this clade the derived feature of ovoid antennal clubs formed by tight appression of the apical two segments, it differs from its putative extant relatives in its possession of the plesiomorphic complement of 11 antennomeres, without any fusions of segments. The fossil taxon signifies a biotic link between early Eocene India and continental Africa, and marks the Cenozoic emergence of a tropical leaf litter arthropod fauna approaching that of contemporary, ant-dominated rainforests.

First record of the subfamily Choraginae (Coleoptera: Anthribidae) from Eocene Baltic amber

ABSTRACT A new species, Eduardoxenus rasnitsyni n. sp., of the fungus weevil tribe Valenfriesiini (Coleoptera: Anthribidae: Choraginae), is described from Eocene Baltic amber. This new species is similar to E. unicus Legalov, Nazarenko and Perkovsky, 2018 from Rovno amber but differs in the rounded, more convex eyes, wide antennal club, and the lateral carina reaching the middle of the pronotum. This is the first record of the subfamily Choraginae from Baltic amber.

Distribution, Morphology and Phenology of Anthrenus Nipponensis Kalik & Ohbayashi (Coleoptera: Dermestidae)

Little is known about the eastern Palaearctic species Anthrenus nipponensis, a member of the Palaearctic A. pimpinellae species complex. In the current study, a morphometric examination of specimens held in the Natural History Museum, London, is carried out. A. nipponensis is larger and narrower than most other species belonging to the complex. The unusual shape of the antennal club is illustrated and discussed. The male genitalia are small but of comparable size to several other Anthrenus species relative to body length. The accuracy of published drawings of A. nipponensis aedeagi is discussed. The literature is searched for records of A. nipponensis to produce a geographical and phenological distribution. The species is distributed across Japan, the Korean peninsula, north-eastern corner of China, and the south-eastern tip of Russia. The adult flight season peaks during the second half of May. Details on the life history are included.

The Pheidole Westwood, 1839 ants (Formicidae: Myrmicinae) in Colombia: new records including two species with remarkable morphology.

Pheidole is one of the most diverse groups of ants in the World, with more than 630 species known from the Neotropical Region. As part of studies on the ant fauna of Colombia, a contribution to the taxonomy of these ants is presented here. The worker subcastes of Pheidole praeusta Roger are redescribed, this being the first record of a trimorphic species outside the Nearctic region. Pheidole amata Forel is proposed as a junior synonym of Pheidole praeusta. Pheidole rogeripolita Longino is identified as the first species in the New World with a 5-segmented antennal club, and the third species with such antennal club in the world. Pheidole distorta Forel, a species described 120 years ago, is redescribed, and notes on its reproductive caste are offered. The description and diagnosis of the Pheidole iceni Fernndez soldier is amended. New species records for the country and South America are listed. Multifocus photographs of P. praeusta, and P. rogeripolita are offered.

A new fossil genus of minute-clubbed beetles (Coleoptera: Cucujoidea: Monotomidae) from Paleogene amber of Europe

ABSTRACT A new genus and species of Monotomidae, Rovnoeurops mckellari gen. et sp. nov., placed in the tribe Europini, is described and figured from Late Eocene Rovno amber. An extinct monotomid genus is documented in Cenozoic amber for the first time. Rovnoeurops gen. nov. can be distinguished from 27 extant genera of Europini by the combination of the following characters: distinct, short pubescence of dorsum, neck constriction behind eyes absent, short temples, stout antennae, 2-segmented antennal club, finely crenulate lateral pronotal margins, pronotum with median impression, regular elytral punctation, long femoral lines and intercoxal process of abdominal ventrite 1 widely rounded.