Limbodessus moni sp. nov., a new high altitudinal diving beetle from the Grasberg in West Papua, Indonesia (Coleoptera: Dytiscidae, Bidessini).

Limbodessus moni sp. nov. is described from Lake Anderson and from small, richly vegetated swampy areas around alpine lakes at 3,970 m a.s.l. near the Grasberg Mine (Carstensz Pyramid) in the Central Mountain Range of New Guinea. The record of the new species marks the altitudinal maximum of a diving beetle in New Guinea. The new species is morphologically similar to L. alexanderi Balke & Hendrich, 2015 in terms of body size and dark coloration; however, both species can be easily separated by the shape of the median lobe and the more moniliform female antennomeres, not forming a conspicuous club as in L. alexanderi. A modified key for all five Limbodessus species from New Guinea and adjacent islands is presented.

Austrelatus gen. nov., a new genus of Australasian diving beetles (Coleoptera, Dytiscidae, Copelatinae), with the discovery of 31 new species from New Guinea.

Herein, Austrelatusgen. nov. (type species: Copelatusirregularis W.J. Macleay, 1871) is described for a distinctive lineage of predominantly Australasian species previously assigned to Copelatus Erichson, 1832. The new genus was retrieved as well supported, monophyletic clade in phylogenetic analysis of DNA sequences data using Bayesian and parsimony approaches. The main morphological diagnostic character of Austrelatus is a complex median lobe of the aedeagus, with evident dorsal and ventral sclerites usually divided in apical half into two lobes of different shape or otherwise modified. Morphological comparison of the new genus with other Copelatinae genera, especially with Copelatus and Exocelina Broun, 1886, and a generic key to the New Guinean Copelatinae are provided. New combinations are established for 31 already described species mainly from the Australian Region (all from Copelatus): Austrelatusadelbert (Megna, Atthakor, Manaono, Hendrich & Balke, 2017), comb. nov.; A.badeni (Sharp, 1882), comb. nov.; A.bakewelli (J. Balfour-Browne, 1939), comb. nov.; A.baranensis (Hájek, Shaverdo, Hendrich & Balke, 2021), comb. nov.; A.bougainvillensis (Hájek, Shaverdo, Hendrich & Balke, 2021), comb. nov.; A.boukali (Hendrich & Balke, 1998), comb. nov.; A.clarki (Sharp, 1882), comb. nov.; A.daemeli (Sharp, 1882), comb. nov.; A.davidi (Wewalka, 2017), comb. nov.; A.deccanensis (Sheth, Ghate & Hájek, 2018), comb. nov.; A.fidschiensis (Zimmermann, 1928), comb. nov.; A.gestroi (Régimbart, 1892), comb. nov.; A.irregularis (W.J. Macleay, 1871), comb. nov.; A.kaszabi (Guignot, 1956), comb. nov.; A.kietensis (Hájek, Shaverdo, Hendrich & Balke, 2021), comb. nov.; A.laevipennis (Hájek, Shaverdo, Hendrich & Balke, 2021), comb. nov.; A.luteomaculatus (Guignot, 1956), comb. nov.; A.maushomi (Sheth, Ghate & Hájek, 2018), comb. nov.; A.neoguineensis (Zimmermann, 1919), comb. nov.; A.nigrolineatus (Sharp, 1882), comb. nov.; A.papuensis (J. Balfour-Browne, 1939), comb. nov.; A.parallelus (Zimmermann, 1920a), comb. nov.; A.schuhi (Hendrich & Balke, 1998), comb. nov.; A.sibelaemontis (Hájek, Hendrich, Hawlitschek & Balke, 2010), comb. nov.; A.strigosulus (Fairmaire, 1878), comb. nov.; A.ternatensis (Régimbart, 1899), comb. nov.; A.uludanuensis (Hendrich & Balke, 1995), comb. nov.; A.urceolus (Hájek, Shaverdo, Hendrich & Balke, 2021), comb. nov.; A.variistriatus (Hájek, Shaverdo, Hendrich & Balke, 2021), comb. nov.; A.wallacei (J. Balfour-Browne, 1939), comb. nov. and A.xanthocephalus (Régimbart, 1899), comb. nov.Austrelatus species from New Guinea are divided into two informal species groups, the A.neoguineensis group and A.papuensis group, and A.fumatosp. nov. and A.setiphallussp. nov. standing aside of them. The A.neoguineensis group is introduced with three previously known species and 29 new species described here based on the morphological characters and Cox1 data: Austrelatusbaliemsp. nov., A.bormensissp. nov., A.brazzasp. nov., A.debulensissp. nov., A.fakfaksp. nov., A.febrisaurisp. nov., A.fojaensissp. nov., A.garainensissp. nov., A.innominatussp. nov., A.lembenensissp. nov., A.lisaesp. nov., A.manokwariensissp. nov., A.mimikasp. nov., A.mirificussp. nov., A.moreguinensissp. nov., A.nadjaesp. nov., A.oksibilensissp. nov., A.pseudoneoguineensissp. nov., A.pseudoksibilensissp. nov., A.rajaampatensissp. nov., A.rouaffersp. nov., A.rugosussp. nov., A.sandaunensissp. nov., A.sarmiensissp. nov., A.securiformissp. nov., A.testegensissp. nov., A.toricellisp. nov., A.vagauensissp. nov., and A.wanggarensissp. nov.Copelatusvagestriatus Zimmermann, 1919, syn. nov. is recognised as a junior subjective synonym of A.clarki (Sharp, 1882). The lectotypes of Copelatusgestroi Régimbart, 1892, C.neoguineensis Zimmermann, 1919 and C.xanthocephalus Régimbart, 1899 are designated. All species are (re)described, and their important species characters (genitalia, habitus, and colour patterns) are illustrated. Keys to all species are provided. The known distribution and habitat preferences of each species are outlined briefly. New Guinean Austrelatus occupy a variety of stagnant water habitats, either lentic sensu stricto, or standing water associated with lotic habitats (e.g., backflows, rockpools, intermittent / ephemeral stream pools).

Eastern Colombian Páramo Liodessus Guignot, 1939 diving beetles are genetically structured, but show signs of hybridization, with description of new species and subspecies (Coleoptera, Dytiscidae).

We studied Liodessus diving beetles from six eastern Colombian Páramo areas, as well as from the Altiplano. We discovered a highly characteristic new species, based on male genital morphology, Liodessussantarositasp. nov., in the Páramo de Guantiva-Rusia. Specimens from the Altiplano around Bogotá, and the Páramos of Almorzadero, Chingaza, Matarredonda, Rabanal y Rio Bogotá and Sumapaz form one clade of genetically similar populations based on mitochondrial Cox1 sequence data. The individuals of this clade are sub-structured according to their geographic distribution. The populations differ from each other mainly in terms of body size and coloration and, at most, subtly in their genital morphology. In two cases, we find putative hybrid populations between Altiplano and Páramo areas. We suggest that the different Páramo populations are in an early phase of speciation, and perhaps already genetically isolated in some cases. They are here assigned subspecies status to highlight these ongoing processes pending more comprehensive geographic sampling and use of genomic data. We refer to this clade as the Liodessusbogotensis complex, containing Liodessusb.bogotensis Guignot, 1953; Liodessusb.almorzaderossp. nov.; Liodessusb.chingazassp. nov.; Liodessusb.lacunaviridis Balke et al., 2021, stat. nov.; Liodessusb.matarredondassp. nov., and Liodessusb.sumapazssp. nov.

A new species of Clypeodytes Rgimbart, 1894 from China (Coleoptera, Dytiscidae: Bidessini).

The diving beetle Clypeodytes limpidus sp. nov. is described from western Yunnan, China. It is the second known species of the genus Clypeodytes Rgimbart, 1894 from China and belongs to the subgenus Hypoclypeus Guignot, 1950. It can be distinguished from C. bufo (Sharp, 1890), the only other Chinese Clypeodytes species, by the shape of the median lobe, the more rounded body and the elytral pattern. A Chinese specimen of C. bufo is illustrated, and the species is recorded for the first time for Laos.

A new Colombian species of Liodessus diving beetles from the Páramo de Sumapaz (Coleoptera, Dytiscidae, Bidessini).

Liodessuspicinus sp. nov. is described from the Páramo de Sumapaz near Bogota D.C. at 3,500 m above sea level. The species can be distinguished from the other Colombian Liodessus species by its dark coloration, discontinuous habitus, shiny surface of the pronotum and elytron, presence of a distinct occipital line, distinct basal pronotal striae, short or even faint basal elytral striae, as well as by its distinct geographic distribution and cox1 signature.

Taxonomic revision of Australasian diving beetles in the genus Leiodytes Guignot, 1936 (Coleoptera: Dytiscidae, Bidessini).

Bidessus migrator Sharp, 1882, so far assigned to Clypeodytes Régimbart, 1894, and widely distributed in Australia and New Guinea, is re-described. Based on morphological and molecular evidence, it is here transferred to Leiodytes Guignot, 1936. Bidessus loriae Régimbart, 1892 is found to be a junior subjective synonym of L. migrator. We describe the following new species: Leiodytes surianiae sp. nov. (eastern New Guinea, northeast coast of Queensland), and Leiodytes wattsi sp. nov. (southern New Guinea and Darwin area to northern Queensland). We delineate the species using characters such as male genital structure and beetle size, shape and color pattern. Mitochondrial Cox1 data for 27 individuals, representing all three Australasian species, were generated and revealed clusters congruent with the morphological evidence. In Australia Leiodytes only occurs in the tropical and subtropical northern part of the continent. None of the species is endemic to Australia. The species are mainly lentic, occurring in seasonal swamps, flooded meadows and pools of intermittent rivers and temporary creeks.

Coverage and quality of DNA barcode references for Central and Northern European Odonata.

BACKGROUND: Dragonflies and damselflies (Odonata) are important components in biomonitoring due to their amphibiotic lifecycle and specific habitat requirements. They are charismatic and popular insects, but can be challenging to identify despite large size and often distinct coloration, especially the immature stages. DNA-based assessment tools rely on validated DNA barcode reference libraries evaluated in a supraregional context to minimize taxonomic incongruence and identification mismatches. METHODS: This study reports on findings from the analysis of the most comprehensive DNA barcode dataset for Central European Odonata to date, with 103 out of 145 recorded European species included and publicly deposited in the Barcode of Life Data System (BOLD). The complete dataset includes 697 specimens (548 adults, 108 larvae) from 274 localities in 16 countries with a geographic emphasis on Central Europe. We used BOLD to generate sequence divergence metrics and to examine the taxonomic composition of the DNA barcode clusters within the dataset and in comparison with all data on BOLD. RESULTS: Over 88% of the species included can be readily identified using their DNA barcodes and the reference dataset provided. Considering the complete European dataset, unambiguous identification is hampered in 12 species due to weak mitochondrial differentiation and partial haplotype sharing. However, considering the known species distributions only two groups of five species possibly co-occur, leading to an unambiguous identification of more than 95% of the analysed Odonata via DNA barcoding in real applications. The cases of small interspecific genetic distances and the observed deep intraspecific variation in Cordulia aenea (Linnaeus, 1758) are discussed in detail and the corresponding taxa in the public reference database are highlighted. They should be considered in future applications of DNA barcoding and metabarcoding and represent interesting evolutionary biological questions, which call for in depth analyses of the involved taxa throughout their distribution ranges.

A review of Copelatus diving beetles from the Solomon Islands, reporting the discovery of six new species (Coleoptera, Dytiscidae, Copelatinae).

The first account of the genus Copelatus Erichson, 1832 in the Solomon Islands is provided, reporting 10 species for the Archipelago. Six of these are new to science: C. baranensis sp. nov., C. laevipennis sp. nov., C. urceolus sp. nov., and C. variistriatus sp. nov. from Guadalcanal and C. bougainvillensis sp. nov., and C. kietensis sp. nov. from Bougainville. Copelatus tulagicus Guignot, 1942, described from Tulaghi Island of the Solomons, is recorded from Guadalcanal and Santa Isabel for the first time. The widely distributed Australasian C. portior Guignot, 1956 is reported from the Solomon Islands (Guadalcanal and Ontong Java Atoll) for the first time. Two species from Guadalcanal remain unidentified since they are so far known only from a limited number of females.

A DNA barcode library for ground beetles of Germany: the genus Pterostichus Bonelli, 1810 and allied taxa (Insecta, Coleoptera, Carabidae).

Species of the ground beetle genus Pterostichus Bonelli, 1810 are some of the most common carabids in Europe. This publication provides a first comprehensive DNA barcode library for this genus and allied taxa including Abax Bonelli, 1810, Molops Bonelli, 1810, Poecilus Bonelli, 1810, and Stomis Clairville, 1806 for Germany and Central Europe in general. DNA barcodes were analyzed from 609 individuals that represent 51 species, including sequences from previous studies as well as more than 198 newly generated sequences. The results showed a 1:1 correspondence between BIN and traditionally recognized species for 44 species (86%), whereas two (4%) species were characterized by two BINs. Three BINs were found for one species (2%), while one BIN for two species was revealed for two species pairs (8%). Low interspecific distances with maximum pairwise K2P values below 2.2% were found for four species pairs. Haplotype sharing was found for two closely related species pairs: Pterostichus adstrictus Eschscholtz, 1823/Pterostichus oblongopunctatus (Fabricius, 1787) and Pterostichus nigrita Paykull, 1790/Pterostichus rhaeticus Heer, 1837. In contrast to this, high intraspecific sequence divergences with values above 2.2% were shown for three species (Molops piceus (Panzer, 1793), Pterostichus panzeri (Panzer, 1805), Pterostichus strenuus (Panzer, 1793)). Summarizing the results, the present DNA barcode library does not only allow the identification of most of the analyzed species, but also provides valuable information for alpha-taxonomy as well as for ecological and evolutionary research. This library represents another step in building a comprehensive DNA barcode library of ground beetles as part of modern biodiversity research.

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

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

Limbodessus skalei sp. nov., a new diving beetle species from the west Papuan Archipelago (Coleoptera: Dytiscidae, Bidessini).

Here we describe Limbodessus skalei sp. nov. from the island of Waigeo, off the coast of West Papua. It can be easily distinguished from the nearby New Guinea mainland species as well as the other members of the genus by its small size and testaceous elytra with conspicuous darker broad basal and subapical patches. Altogether four Limbodessus species are now known from the New Guinea region.

The "minute diving beetles" of southern Australia - taxonomic revision of Gibbidessus Watts, 1978, with description of six new species (Coleoptera, Dytiscidae, Bidessini).

Morphology and mitochondrial DNA sequence data are used to reassess the taxonomy of Australian diving beetles previously assigned to the genera Uvarus Guignot, 1939 and Gibbidessus Watts, 1978. Gibbidessus was described as a monotypic genus for Gibbidessus chipi Watts, 1978. The genus is significantly extended here. Based on molecular systematic evidence, Uvarus pictipes (Lea, 1899) is transferred to Gibbidessus. Gibbidessus chipi and Gibbidessus pictipes comb. nov. are redescribed, and six new species are described: Gibbiddessus atomus sp. nov. (SW Australia, Northcliffe area) [the smallest epigean diving beetle in Australia], G. davidi sp. nov. (SW Australia), G. drikdrikensis sp. nov. (Victoria), G. kangarooensis sp. nov. (SA Kangaroo Island), G. pederzanii sp. nov. (SW Australia, Nannup area), and G. rottnestensis sp. nov. (SW Australia). Species are delineated using characters such as male genital structure and beetle size, shape and colour pattern. Mitochondrial Cox1 data for 27 individuals, representing five species, were generated, and revealed clusters congruent with the morphological evidence. Gibbidessus occur in southern Australia, with the centre of diversification in the isolated peat- and wetlands of SW Australia. All species occur in very shallow water of seasonal, exposed or half-shaded wetlands and flooded meadows.

DNA metabarcoding for biodiversity monitoring in a national park: Screening for invasive and pest species.

DNA metabarcoding was utilized for a large-scale, multiyear assessment of biodiversity in Malaise trap collections from the Bavarian Forest National Park (Germany, Bavaria). Principal component analysis of read count-based biodiversities revealed clustering in concordance with whether collection sites were located inside or outside of the National Park. Jaccard distance matrices of the presences of barcode index numbers (BINs) at collection sites in the two survey years (2016 and 2018) were significantly correlated. Overall similar patterns in the presence of total arthropod BINs, as well as BINs belonging to four major arthropod orders across the study area, were observed in both survey years, and are also comparable with results of a previous study based on DNA barcoding of Sanger-sequenced specimens. A custom reference sequence library was assembled from publicly available data to screen for pest or invasive arthropods among the specimens or from the preservative ethanol. A single 98.6% match to the invasive bark beetle Ips duplicatus was detected in an ethanol sample. This species has not previously been detected in the National Park.

Hydaticus (Prodaticus) hauthi sp. nov., a new diving beetle from the cloud forest in the Cordillera El Sira, Peru (Coleoptera: Dytiscidae).

A new species of the genus Hydaticus Leach, 1817, subgenus Prodaticus Sharp, 1882 (Coleoptera: Dytiscidae) has been discovered in the mountains of Cerros del Sira, Peru. It is here described as Hydaticus (Prodaticus) hauthi sp. nov.. It is morphologically similar to the Peruvian H. panguana Megna, Balke, Apenborn Hendrich, 2019. The new species differs from H. panguana by its almost complete black dorsal surface and the shape of the median lobe. Diagnostic characters of both species, including illustrations of male genitalia and habitus, are presented, and a modified key for the 12 Neotropical species is provided.

A Baltic amber species of the diving beetle genus Coptotomus Say, 1830 (Coleoptera: Dytiscidae: Coptotominae).

We provide the first report of the Nearctic diving beetle subfamily Coptotominae Van den Branden, 1885 for the Paleactic Region, based on † Coptotomus balticus sp. n. from Baltic amber. Coptotomus Say, 1830 is otherwise distributed with five extant species and one subspecies in the Nearctic Region. The new species is the smallest species of the genus and thus readily separated from the extant taxa.

Taxonomic revision of Australian Copelatus Erichson, 1832 (Coleoptera, Dytiscidae, Copelatinae).

The genus Copelatus in Australia is revised and nine species are recognised. One new species, Copelatus martinbaehri sp. nov., is described from Papua New Guinea (Central Province) and Cape York Peninsula (Iron Range NP and Mt Tozer). Copelatus divisus Watts, 1978, syn. nov., is considered a junior synonym of C. portior Guignot, 1956, described from New Guinea. Species delimitation is based on the morphological characters and Cox1 data. All species are (re)described, and their important species characters (median lobes, parameres, habitus and colour patterns) are illustrated. A key to all nine species is provided. The known distribution and habitat preferences of each species are outlined briefly. In Australia, all nine species are distributed in the northern half of the continent. Four species are also reported from New Guinea: in addition to C. martinbaehri sp. nov., we record C. clarki Sharp, 1882 for the first time from southern New Guinea, and consider literature records of C. irregularis W.J. Macleay, 1871 and C. marginatus Sharp, 1882 from New Guinea as doubtful. Copelatus portior is widely distributed in Australasia, while C. tenebrosus is widely distributed in the Indomalayan and Australasian realms. All Australian Copelatus are confirmed to be lentic, found in a large variety of stagnant water, mainly in lowland areas up to 250 m.

High genetic variation within mitochondrial CO1 in Middle European Thanasimus formicarius (Linné, 1758) (Coleoptera: Cleridae).

The aim of this study is to assess the species status of the Middle-European Thanasimus Latreille, 1806 species using mitochondrial CO1 sequence data. Molecular biological results clearly support the synonymy of T. pectoralis (Fuss, 1863) and T. rufipes (Brahm, 1797) with T. femoralis (Zetterstedt, 1828) as already proposed by Kolibác (1992). Results of the present study indicate high genetic variation within T. formicarius (Linné, 1758) and emphasize the study of population dynamics of T. formicarius within Europe. Furthermore, preliminary screening of all available T. formicarius sequences on BOLD and Genbank (shorter than 500bp) indicates the presence of a "Continental" and a more "Atlantic" clade in T. formicarius. To support our hypothesis of a probably cryptic species among T. formicarius, more studies, with more specimens from different populations, especially from southern England, northern France and the northern part of the Iberian Peninsula, will be necessary.

The return of the Duke-locality data for Megadytes ducalis Sharp, 1882, br />the world's largest diving beetle, with notes on related species (Coleoptera: Dytiscidae).

Megadytes (Bifurcitus) ducalis Sharp, 1882 is the largest diving beetle in the world and has been considered a candidate for the world's rarest insect (Jones 2010). It was described from "Brazil", is only known from the male holotype in the Natural History Museum (London), and typically thought to be extinct. Here we report the finding of 10 additional specimens, all collected at the end of the 19th century, which were discovered incidentally in different historical collections, including drawers with unsorted diving beetle accessions of the Muséum National d'Histoire Naturelle (Paris). These specimens, whilst old, reveal exact locality data for the first time, enabling focused field campaigns to attempt to rediscover this giant alive. Locality labels all indicate Santo Antônio da Barra (present name Condeúba), in the southern part of Bahia, Brazil, suggesting that the species may have a restricted distribution in wetter parts of the Brazilian savanna or cerrado. We also describe the female of M. ducalis for the first time and present new records of the putatively closely related species Megadytes magnus Trémouilles Bachmann, 1980 and M. lherminieri (Guérin-Méneville, 1829), the latter being recorded for the first time from Ecuador. These three morphologically similar species together form the subgenus Bifurcitus Brinck, 1945 and we provide photographs of their habitus, median lobes and other morphological details.

A review of Peruvian diving beetles of the genus Hydaticus Leach, 1817, with description of Hydaticus (Prodaticus) panguana sp. nov. and notes on other Neotropical species (Coleoptera: Dytiscidae).

We review the Peruvian Hydaticus Leach, 1817 (Coleoptera: Dytiscidae) and describe Hydaticus panguana sp. nov. from Huánuco Department. In the context of this work, we also provide new country records for several species: Hydaticus lateralis Laporte, 1835 (for Peru, Guyana, Venezuela, Suriname); H. xanthomelas (Brullé, 1837) (for Peru); H. subfasciatus Laporte, 1835 (for Colombia); H. fractivittis Guignot, 1951 (for Paraguay). Hydaticus riehli Wehncke, 1876 and H. verecundus Clark, 1864, described from "Cuba" and "South America", respectively, were probably mislabelled specimens, and do not belong to the Neotropical fauna. Diagnostic characters, including illustrations of male genitalia and habitus, are presented for seven of the 11 Neotropical species, and a modified key is provided. Altogether four species of Hydaticus are now known from Peru.

†Japanolaccophilus beatificus sp. n. from Baltic amber and a key to the Laccophilinae genera of the World (Coleoptera: Laccophilinae).

We provide the first report of the subfamily Laccophilinae Gistel, 1848 from Baltic amber, based on a female specimen collected in Russia, Kaliningrad Region, Yantarnii (Jantarny) mine. This specimen represents a new species and could be assigned to the extant genus Japanolaccophilus Satô, 1972. To date this genus was monotypic with one species in Japan. The new species is here described as †J. beatificus sp. n. and compared with the extant Japanolaccophilus niponensis (Kamiya, 1939). We also provide a modified key to the Laccophilinae genera of the World, as we found minor errors or ambiguities in recent keys.