A New Species of Megaceropsis Dechambre, 1976 and a New Record of Megaceropsis quadridentata Dechambre, 1976 (Coleoptera, Melolonthidae, Dynastinae, Oryctini).

Megaceropsis Dechambre, 1976 (Coleoptera, Melolonthidae, Dynastinae, Oryctini) is a South American genus with two known species until now: Megaceropsis quadridentata Dechambre, 1976 and Megaceropsis lecourti Dechambre, 1996. We describe a third species herein: Megaceropsis kleytoni sp. nov., from Brazil. Illustrations, a distributional map, and an identification key including all Megaceropsis species are provided. Additionally, a first record of M. quadridentata from Brazil is presented.

Testing and optimizing metabarcoding of iDNA from dung beetles to sample mammals in the hyperdiverse Neotropics.

Over the past few years, insects have been used as samplers of vertebrate diversity by assessing the ingested-derived DNA (iDNA), and dung beetles have been shown to be a good mammal sampler given their broad feeding preference, wide distribution and easy sampling. Here, we tested and optimized the use of iDNA from dung beetles to assess the mammal community by evaluating if some biological and methodological aspects affect the use of dung beetles as mammal species samplers. We collected 403 dung beetles from 60 pitfall traps. iDNA from each dung beetle was sequenced by metabarcoding using two mini-barcodes (12SrRNA and 16SrRNA). We assessed whether dung beetles with different traits related to feeding, nesting and body size differed in the number of mammal species found in their iDNA. We also tested differences among four killing solutions in preserving the iDNA and compared the effectiveness of each mini barcode to recover mammals. We identified a total of 50 mammal OTUs (operational taxonomic unit), including terrestrial and arboreal species from 10 different orders. We found that at least one mammal-matching sequence was obtained from 70% of the dung beetle specimens. The number of mammal OTUs obtained did not vary with dung beetle traits as well as between the killing solutions. The 16SrRNA mini-barcode recovered a higher number of mammal OTUs than 12SrRNA, although both sets were partly non-overlapping. Thus, the complete mammal diversity may not be achieved by using only one of them. This study refines the methodology for routine assessment of tropical mammal communities via dung beetle 'samplers' and its universal applicability independently of the species traits of local beetle communities.

Dung beetles in South American pasturelands / Besouros rola-bostas em pastagens sul-americanas

Abstract Pasturelands are characterized as grasslands utilized for cattle raising and consist of natural or exotic vegetation, predominantly grasses. In the context of sustainable production, the biodiversity of insects within grazing environments holds significant value. Dung beetles play a crucial role in sustaining pasturelands as the burial of feces by these beetles fosters ecological services indispensable for maintaining a robust and healthy environment. Given that different dung beetle species contribute to distinct environmental benefits, a comprehensive understanding of the species present in pasturelands, their origins, and the ecological services they provide is imperative. This study endeavors to compile comprehensive information on dung beetle species native to South America, emphasizing taxonomic precision and a confirmed affinity for cattle dung. Our findings are derived from a synthesis of literature and observational data, incorporating location information obtained from taxonomic revisions and specimen labels of specimens housed at CEMT. In South America, a total of 57 dung beetle species are documented that inhabit grazing areas and actively feed on cattle manure. These areas span diverse biomes encompassing native and/or introduced grasslands, which may include deforested sections within forest biomes such as Chaco, Pantanal, Cerrado, Caatinga, Pampa, Atlantic Forest, Amazon Forest, Paramo, Puna, Llanos, and Patagonia. The preponderance of species identified fall within the paracoprid category, recognized as particularly vital for the sustainability of pasturelands. Despite their acknowledged importance, a noticeable knowledge gap impedes the effective conservation of these species. This gap is a focal point of discussion in this study, addressing the challenges and opportunities for enhancing conservation efforts. The species documented in this research exhibit notable economic and environmental relevance in the context of sustainable livestock production, emphasizing the urgency and significance of initiatives that prioritize their conservation.

Resumo Pastagens são áreas formadas por vegetação nativa ou exótica, principalmente gramíneas, e são utilizadas na pecuária. A diversidade de insetos em áreas de pastagens é muito valiosa, especialmente quando consideramos os métodos de produção sustentável. Besouros rola-bostas são importantes para a sustentabilidade em pastagens porque o enterrio de esterco promove benefícios essenciais para a manutenção do ambiente pastoril. Espécies diferentes exercem diferentes serviços ecossistêmicos, logo é necessário saber quais espécies estão presentes em áreas de pastoreio para saber quais são os benefícios que elas podem proporcionar. Aqui reunimos todas as informações disponíveis para as espécies taxonomicamente bem definidas de rola-bostas nativos da América do Sul e que são conhecidas por utilizar fezes bovinas como recurso para alimentação e nidificação. Usamos dados encontrados na literatura, em observações de campo e em etiquetas de espécimes depositados na CEMT. São registradas 57 espécies de rola-bostas nativos da América do Sul que se alimentam e nidificam em fezes bovinas, e estas estão distribuídas nos seguintes biomas: Chaco, Pantanal, Cerrado, Caatinga, Pampa, áreas abertas da Mata Atlântica e da Floresta Amazônia, Paramo, Puna, Llanos e Patagônia. A maioria das espécies são de paracoprídeos e estes são considerados os mais importantes para as áreas de pastagem. No entanto, existe uma grande lacuna de conhecimento em história natural, o que dificulta a efetividade da conservação dessas espécies. Todas as espécies listadas neste trabalho têm potencial relevância econômica e ambiental na pecuária sustentável e, portanto, o estudo e conservação delas devem ser priorizadas.

Pervasive gaps in Amazonian ecological research.

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%-18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost.

Bait attractiveness changes community metrics in dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae).

Species relative abundance (SRA) is an essential attribute of biotic communities, which can provide an accurate description of community structure. However, the sampling method used may have a direct influence on SRA quantification, since the use of attractants (e.g., baits, light, and pheromones) can introduce additional sources of variation in trap performance. We tested how sampling aided by baits affect community data and therefore alter derived metrics. We tested our hypothesis on dung beetles using data from flight interception traps (FITs) as a baseline to evaluate baited pitfall trap performance. Our objective was to assess the effect of bait attractiveness on estimates of SRA and assemblage metrics when sampled by pitfall traps baited with human feces.Dung beetles were sampled at three terra firme primary forest sites in the Brazilian Amazon. To achieve our objective, we (i) identified species with variable levels of attraction to pitfall baited with human feces; (ii) assessed differences in SRA; and (iii) assessed the effect of bait on the most commonly used diversity metrics derived from relative abundance (Shannon and Simpson indices). We identified species less and highly attracted to the baits used, because most attracted species showed greater relative abundances within baited pitfall traps samples compared with our baseline. Assemblages sampled by baited pitfall traps tend to show lower diversity and higher dominance than those sampled by unbaited FITs. Our findings suggest that for ecological questions focused on species relative abundance, baited pitfall traps may lead to inaccurate conclusions regarding assemblage structure. Although tested on dung beetles, we suggest that the same effect could be observed for other insect taxa that are also sampled with baited traps. We highlight a need for further studies on other groups to elucidate any potential effects of using baits.

A Taxonomic Revision of the Dichotomius reclinatus (Felsche, 1901) Species Group (Coleoptera: Scarabaeidae: Scarabaeinae).

The taxonomic revision of the Dichotomius reclinatus species group (Coleoptera: Scarabaeidae: Scarabaeinae: Dichotomius Hope, 1838) sensu Arias-Buriticá and Vaz-de-Mello (2019) is presented. The group comprises four species previously included in the Dichotomius buqueti species group: Dichotomius horridus (Felsche, 1911) from Brazil, French Guiana, and Suriname; Dichotomius nimuendaju (Luederwaldt, 1925) from Bolivia, Brazil, and Peru; Dichotomius quadrinodosus (Felsche, 1901) from Brazil; and Dichotomius reclinatus (Felsche, 1901) from Colombia and Ecuador. A definition of the D. reclinatus species group and an identification key are presented. In the key we included to Dichotomius camposeabrai Martínez, 1974, this species due the external morphology can be confused with the D. reclinatus species group and for the first time photographs of males and female of this species are presented. For each species of the D. reclinatus species group, the following information is provided: taxonomic history, citation of the species in published literature, redescription, list of material examined, photographs of the external morphology, illustrations of male genital organs and the endophallites, and distribution map.

Dung beetles from two sustainable-use protected forests in the Brazilian Amazon.

Background: The Amazon Forest is one of the world's most biodiverse ecosystems and yet its protected areas are understudied concerning insects and other invertebrates. These organisms are essential for tropical forests due to their ecological processes, with some species being very sensitive to habitat disturbances. Dung beetles (Coleoptera, Scarabaeidae, Scarabaeinae) have been used as bioindicators for more than 30 years and were surveyed to assess the insect biodiversity of two sustainable-use forest reserves in the Brazilian Amazon. New information: We report inventories of dung beetles from two Amazonian forest reserves in Pará State, Brazil: the Tapajós National Forest and the Carajás National Forest. Surveys were carried out with baited-pitfall traps installed in 2010, 2016, 2017 and 2019. We collected a total of 3,772 individuals from 19 genera and 96 species. We highlight the importance of Amazonian protected areas as refugia for insect biodiversity, particularly dung beetles, which contribute to many key ecosystem processes.

Identification guide of dung beetle species (Coleoptera: Scarabaeidae: Scarabaeinae) of the Brazilian Pantanal / Guia de identificação de espécies de besouros rola-bostas (Coleoptera: Scarabaeidae: Scarabaeinae) do Pantanal Brasileiro

Abstract The Pantanal is the largest seasonal freshwater wetland on Earth, characterized by the seasonal flooding and complex mosaic vegetation, which determines its biodiversity. Among this biodiversity, dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae) are a group of insects that perform important ecological functions, such as: nutrient cycling, seed dispersion and parasite control. In order to mitigate the lack of information on dung beetle fauna of the Brazilian Pantanal, we conducted a bibliographic search of virtually all literature published until november-2020 on dung beetles sampled in the Pantanal. In addition, we had accessed to the records the largest collection of the dung beetle species from Brazilian Pantanal. We recorded 68 dung beetle species of 30 genera. The genera Canthon Holffmanseg 1847 is the most diverse with 13 species recorded. Although our knowledge about the dung beetle fauna in this ecosystem is still incipient, our results demonstrated a high richness of dung beetles in the Brazilian Pantanal. In addition, our study provides first list of dung beetle species and an illustrated dichotomy key to identify genera and some species occurring in the Brazilian Pantanal. Thus, the use of this guide for identification of dung beetle species and a list of species can be important tools to help researchers and provide incentive for new inventories on dung beetle fauna in the Brazilian Pantanal.

Resumo O Pantanal é a maior área úmida sazonal de água doce Neotropical da Terra, caracterizada pelas inundações sazonais e pela complexa vegetação em mosaico, que determina sua biodiversidade. Dentre essa biodiversidade, os besouros rola-bosta (Coleoptera: Scarabaeidae: Scarabaeinae) são um grupo de insetos que desempenham importantes funções ecológicas, tais como: ciclagem de nutrientes, dispersão de sementes e controle de parasitas. A fim de mitigar a falta de informações sobre a fauna de besouros rola-bosta do Pantanal brasileiro, realizamos uma pesquisa bibliográfica de praticamente toda a literatura publicada até novembro de 2020 sobre besouros rola-bosta amostrados no Pantanal. Além disso, acessamos os registros da maior coleção da espécie de rola-bosta do Pantanal brasileiro. Registramos 68 espécies de besouros rola-bosta de 30 gêneros. O gênero Canthon Holffmanseg 1847 é o mais diverso com 13 espécies registradas. Embora nosso conhecimento sobre a fauna de rola-bostas neste ecossistema ainda seja incipiente, nossos resultados demonstraram uma alta riqueza de besouros rola-bosta no Pantanal brasileiro. Além disso, nosso estudo fornece a primeira lista de espécies de besouros rola-bosta e uma chave de dicotomia ilustrada para identificar gêneros e algumas espécies encontrados no Pantanal brasileiro. Assim, a utilização deste guia para identificação das espécies de besouros rola-bostas e uma lista de espécies podem ser ferramentas importantes para auxiliar pesquisadores e incentivar novos inventários sobre a fauna de besouros rola-bostas no Pantanal brasileiro.

A new genus and species of Neotropical Hybosorinae Erichson, 1847 (Coleoptera: Hybosoridae).

Among the 26 Hybosorinae genera, seven are present exclusively in the Neotropical region. However, Hybosorinae from the New World have been less studied. One new genus and new species collected in Brazil is herein described to this subfamily. The genus is recognizable by the following combination of characters: labium with semicircular mentum; mandibles with lateral projection excavated, separated in the middle by longitudinal carina, inner side sheltering the labrum; antennae with nine antenomeres; scutellar shield with strong punctures at the proximal half; elytra with single rows formed by punctures; and protibia without well-defined denticles.

Linking land-use and land-cover transitions to their ecological impact in the Amazon.

Human activities pose a major threat to tropical forest biodiversity and ecosystem services. Although the impacts of deforestation are well studied, multiple land-use and land-cover transitions (LULCTs) occur in tropical landscapes, and we do not know how LULCTs differ in their rates or impacts on key ecosystem components. Here, we quantified the impacts of 18 LULCTs on three ecosystem components (biodiversity, carbon, and soil), based on 18 variables collected from 310 sites in the Brazilian Amazon. Across all LULCTs, biodiversity was the most affected ecosystem component, followed by carbon stocks, but the magnitude of change differed widely among LULCTs and individual variables. Forest clearance for pasture was the most prevalent and high-impact transition, but we also identified other LULCTs with high impact but lower prevalence (e.g., forest to agriculture). Our study demonstrates the importance of considering multiple ecosystem components and LULCTs to understand the consequences of human activities in tropical landscapes.

Is it time to describe new species without diagnoses?A comment on Sharkey et al. (2021).

New methods in taxonomy and systematics can influence the overall practice of formally naming and describing biodiversity. DNA barcoding has been controversial since its emergence, but now, large scale species descriptions exclusively based on barcodes have created what can be called a 'new quality of performance. Its limitations are discussed from different perspectives: nomenclature, general pragmatism, and problems of DNA-based species delimitation in the light of the central aim of achieving a robust and stable nomenclature of organisms, essential for all applications of biodiversity research. This issue needs to be addressed to prevent restraining the progress of taxonomy and its ability to contribute to modern science.

Extinct before discovered? Epactoidesgiganteus sp. nov. (Coleoptera, Scarabaeidae, Scarabaeinae), the first native dung beetle to Réunion island.

We describe a new species of dung beetle, Epactoidesgiganteus sp. nov., from a single female specimen allegedly collected in the 19th century on Réunion island and recently found at the Muséum national d'Histoire naturelle, Paris. This species differs from other species of Epactoides by larger size and a set of other distinctive morphological characters. Epactoidesgiganteus sp. nov. is the first native dung beetle (Scarabaeinae) of Réunion, and its discovery expands the known area of distribution of the genus Epactoides, which was hitherto believed to be endemic to Madagascar. Like other taxa from Madagascar and peripheral islands (e.g., Comoro, Seychelles, Mascarenes), E.giganteus sp. nov. may have reached Réunion by over-water dispersal. Given the rapid loss of biodiversity on Réunion island and the fact that no additional specimens were re-collected over the last two centuries, it is very likely that E.giganteus sp. nov. has gone extinct. However, we have unconfirmed evidence that the holotype of E.giganteus sp. nov. might be a mislabeled specimen from Madagascar, which would refute the presence of native dung beetles on Réunion. We discuss both hypotheses about the specimen origin and assess the systematic position of E.giganteus sp. nov. by examining most of the described species of Madagascan Epactoides. Additionally, we provide a brief overview of the dung beetle fauna of Mascarene Archipelago.

Towards a comprehensive taxonomic revision of the Neotropical dung beetle subgenus Deltochilum (Deltohyboma) Lane, 1946 (Coleoptera: Scarabaeidae: Scarabaeinae): Division into species-groups.

Deltochilum Eschscholtz, 1822 is perhaps the most speciose genus of the tribe Deltochilini sensu Tarasov & Dimitrov (2016) (Scarabaeidae: Scarabaeinae) and has been traditionally divided into eight subgenera. Among them, the subgenus Deltohyboma Lane, 1946, is the most speciose with 47 species, five of which are described here (D. genieri sp. nov., D. gilli sp. nov., D. susanae sp. nov., D. bolivariensis sp. nov. and D. inesae sp. nov.), and at least 165 species still undescribed. Due to the large number of species, and for practical purposes, the subgenus is here divided into 19 species-groups, with D. inesae sp. nov. left as incertae sedis. This division into species-groups will help in the reliable identification of species and will aid in the completion of the revision of subgenus. This report is the first part of the taxonomic revision of the subgenus Deltohyboma; it is based on the examination of all type specimens and almost 9,800 specimens of which approximately 1,200, mostly males, had their genitalia studied. The 19 species-groups recognized here are based mainly on characters described for the first time for Deltohyboma, namely, the state of a) the anterior margin of the clypeus (between the clypeal teeth), b) the internal margin of hypomera, c) the ventral face of the protibia, d) the posterior margin of the metafemur, and e) several new characters resulting from the first detailed study of the aedeagus and the endophallus of the group. Diagnosis, description, geographic distribution, composition and identifications keys (for males as well as males and females) for the species-groups are provided.

Revision of the Megasoma (Megasoma) gyas (Jablonsky in Herbst, 1785) species group (Coleoptera, Scarabaeidae, Dynastinae).

The taxa of the genus Megasoma Kirby, 1825 (Coleoptera, Scarabaeidae, Dynastinae) related to M. gyas (Jablonsky in Herbst, 1785) are revised. Megasoma (M.) gyas is recognized as a monotypic species restricted to the Caatinga biome of northeastern Brazil. Megasoma gyas rumbucheri Fischer, 1968, is considered as a new synonym of M. gyas. The "long-horned M. gyas" is recognized as a separate polytypic species M. (M.) typhon (Olivier, 1789) with the nominative subspecies occurring through the Mata Atlântica biome of Brazil, from Bahia to São Paulo states and M. (M.) typhon prandii Milani, 2008 restricted to a small area in the state of Santa Catarina, South Brazil. Megasoma gyas porioni Nagai is considered as a new synonym of M. typhon typhon. The "short-horned M. gyas" occurring in Minas Gerais, São Paulo, and southwestern Bahia, is recognized as a separate new species and described as M. (M.) hyperionsp. nov. The paper includes an historical research and the redescriptions of the other nominal species of the genus. Distribution maps and a key to species in the M. (M.) gyas species group (males and females) are also provided.

Notes on the taxonomy of some "Astaena" species described by Burmeister (Coleoptera: Scarabaeidae: Melolonthinae).

In the framework of the taxonomic revision of South American Sericini (Coleoptera: Scarabaeidae: Melolonthinae), we examined the type specimens of the species described by Burmeister (1855) in the genus Astaena Erichson, 1847. A few taxa resulted to not belong to the South American Sericini fauna, either due to different geographical provenience or due to incorrect systematical placement within Sericini. Two new combinations and one new synonymy are proposed: Neoserica pubescens (Burmeister, 1855), new combination (= Neoserica subsetosa Ahrens Fabrizi, 2016: 121, new synonymy) and Manonychus robustus (Burmeister, 1855), new combination.

Insect (Hexapoda) diversity in the oceanic archipelago of Fernando de Noronha, Brazil: updated taxonomic checklist and new records

ABSTRACT Hexapods, commonly known as insects, are a neglected taxonomic group in the Fernando de Noronha archipelago, with unanswered questions about their species richness and the ecological processes in which they are involved (e.g., colonization, introduction, establishment, and extinction). Herein, we provide an updated Hexapod checklist with current nomenclatural combinations. The entomofauna of the Fernando de Noronha archipelago is currently composed of 453 species in 21 orders. The orders, and their respective number of species, are: Blattaria (9), Coleoptera (118), Collembola (29), Dermaptera (3), Diplura (1), Diptera (134), Embioptera (1), Hemiptera (29), Hymenoptera (59), Isoptera (2), Lepidoptera (25), Mantodea (1), Neuroptera (3), Odonata (5), Orthoptera (11), Phasmatodea (1), Phthiraptera (6), Psocoptera (3), Siphonaptera (1), Thysanoptera (10), and Zygentoma (2). The archipelago has 263 new taxon records (family + genera + species). Thirty-eight species (3.39%) were described from local specimens and most of them are likely endemic species. This study more than doubles our knowledge (from the previous 190 records) of the entomofauna in this large Brazilian archipelago. This study also provides a baseline for studies on its conservation status and for implementing future environmental management programs.

Biodiversity studies through public-private partnership (PPP): The case of Fazenda São Nicolau in the northwest of Mato Grosso.

Peugeot-ONF Forest Carbon Sink Project, located at Fazenda São Nicolau (FSN) in Cotriguaçu Municipality, is a public-private initiative and has been supported by several French and Brazilian institutions. Its Research Program includes studies aiming Biodiversity Conservation, Ecology, Carbon Dynamics, Silvicultural Techniques. FSN comprises a high richness of species with more than 20 new species of beetles (Histeridae, Scarabaeidae e Melolonthidae) described among them one endemic genus. A quick overview of the SuperFamily Scarabaeoidea within the FSN area registered 260 species which nearly 100 species might be new to Science. One new species of fish as well as research with amphibian toxins as tools to treat cancer and malaria are also done with material collected at the FSN. Ecology of the decomposer´s fauna at reforestation sites showed that after 10 years, such places were more similar to native forest sites than pastures or abandoned pastures. Finally large mammals studies indicated that many large mammals use FSN as a refuge. We stress the importance to keep the FSN natural habitats linked with the Juruena National Park. The FSN contour is under heavy deforestation which will increase the species loss and turn FSN in one of the few major natural vegetation fragments.

Scarabaeinae dung beetles from Ecuador: a catalog, nomenclatural acts, and distribution records.

The Ecuadorian territory is divided into four natural regions: the coastal lowlands, the Andean highlands, the Amazon basin, and the Galapagos Islands. Each of these regions has its own ecosystems and specific vegetation. The purpose of this work is to compile an updated catalog of the Scarabaeinae (Coleoptera: Scarabaeidae) of Ecuador that includes distributional data and several nomenclatural acts. We compiled data from 25 scientific collections, with the examination of 13,550 scarabaeines; additionally, 390 bibliographic references were reviewed for their taxonomic histories. The Scarabaeinae fauna from Ecuador is represented by 33 genera and 223 species, with 45 range-restricted species; 27 species were erroneously recorded from the country. The following nomenclatural acts are made: (A) two new status as valid species: Canthon (Glaphyrocanthon) ohausi Balthasar, 1939, stat. n., and Deltochilum (Calhyboma) arrowi Paulian, 1939 stat. n.; (B) one new synonym: Uroxysmagnus Balthasar, 1940 = Uroxyslatesulcatus Bates, 1891, syn. n.; (C) two revalidated names: Canthidium (Canthidium) orbiculatum (Lucas, 1857) and Dichotomius (Luederwaldtinia) fortepunctatus (Luederwaldt, 1923); and (D) ten lectotypes designated for: Choeridiumorbiculatum Lucas, 1857; Choeridiumcupreum Blanchard, 1846; Canthidiumcoerulescens Balthasar, 1939; Canthonangustatus Harold, 1867; Canthonangustatusohausi Balthasar, 1939; Deltochilumtessellatum Bates, 1870; Pinotusfortepunctatus Luederwaldt, 1923; Pinotusglobulus Felsche, 1901; Uroxyslatesulcatus Bates, 1891; and Uroxysmagnus Balthasar, 1940. The type specimens related to the new nomenclatural acts are illustrated and the maps of the geographical distribution of all species are provided.

Redefinition and taxonomic revision of the "buqueti" species-group, Dichotomius Hope, 1838 (Coleoptera: Scarabaeidae: Scarabaeinae)

ABSTRACT On the basis of external morphology and genitalia of males, as well as a comparison between different species belonging to other groups of Dichotomius, we propose a redefinition of the "buqueti" species group separated by Luederwaldt (1929). Six species are excluded from this group and transferred to other groups: D. ribeiroi (Pereira, 1954) in the "cotopaxi" group; D. camposeabraiMartínez, 1974 in the "bitiensis" group; D. reclinatus (Felsche, 1901), D. horridus (Felsche, 1911), D. quadrinodosus (Felsche, 1901) and D. nimuendaju (Luederwaldt, 1925) (revalidated species) forming the newly defined "reclinatus" group. The other species kept in the "buqueti" group include D. buqueti (Lucas, 1857) from Brazil (lectotype here designated), D. haroldi (Waterhouse, 1891) from Argentina and D. nutans (Harold, 1867) from Brazil, Argentina and Uruguay. The taxonomic revision of the "buqueti" group are presented, including a history of the included species, a determination key, illustrations of the structures of external morphology, male genitalia and sclerites of the internal sac, and a distribution map.