A revision of the Deltochilum subgenus Aganhyboma Kolbe, 1893 (Coleoptera: Scarabaeidae: Scarabaeinae)

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.

Variations in genetic structure and male genitalia suggest recent lineage diversification in the Neotropical dung beetle complex Canthon cyanellus (Scarabaeidae: Scarabaeinae)

We analysed the genetic divergence and morphology of the aedeagus (i.e. phallobase and parameres) in Canthon cyanellus at different geographical levels. The results from both approaches were compared with the current taxonomic assignment of the C. cyanellus complex, which includes three subspecies. We found a high variation in all the morphological characters of the aedeagus in the populations analysed; the morphometric variation was not geographically structured, either by population or by region. The genealogical analysis indicates a significant genetic structure that does not match either the morphological variation in the male genitalia or the previous subspecific taxonomic classification. Our results suggest that the morphological variation of the aedeagus is seemingly not an isolating reproductive barrier and that the intra- and interpopulation morphological variability of the aedeagus in the C. cyanellus complex does not permit the division into several species. We suggest that other evolutionary forces, such as genetic drift and sexual selection, have influenced the evolution of the male genitalia and the incipient differentiation of this species complex.

Current status of dung beetles (Coleoptera, Scarabaeidae, Scarabaeinae) diversity and conservation in Natural Protected Areas in Chiapas (Mexico)

Natural Protected Areas (NPAs) are consider adequate tools for biodiversity conservation. Currently in Mexico there are 182 federal NPAs classified according to their management objectives. Chiapas is the Mexican state with the highest number of decreed NPAs and also allocates one of the largest territorial extensions for its protection. Unlike other taxa, and despite their proven ability to respond to ecosystem changes, the study of dung beetles within Mexican NPAs has been underestimated, as they are not considered as a priority group within their management and conservation programs. Based on the review of information available in publications and database on dung beetles, a list of 112 species and seven subspecies recorded in 16 of the 19 federal NPAs established in Chiapas is presented. The species recorded by each NPA show a significant correlation with the number of publications, but a low percentage of them correspond to studies with systematic samplings and most of the species reported in several of the NPAs come from sporadic records, which prevents the study of several basic and applied aspects of dung beetles in the region. Therefore, studies that extensively analyze the communities of arthropod groups, such as the Scarabaeinae, are necessary to understand their response to changes in the ecosystem at local and regional scale. It is advisable that these insects be included in the previous justifying studies for the designation or establishment of NPAs and, in turn, considered in the biological monitoring programs of these areas for their capacity as a bioindicator group.

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.