Mario Zunino

Ribosomal DNA Location in the Scarab Beetle Thorectes Intermedius (Costa) (Coleoptera: Geotrupidae) Using Banding and Fluorescent in-situ Hybridization

Mitotic metaphase chromosomes of the scarab beetle Thorectes intermedius (Costa) (Coleoptera Scarabaeoidea: Geotrupidae) were analyzed using various banding methods and fluorescent in-situ hybridization (FISH) with a ribosomal probe. The results obtained indicate that silver and CMA3 staining are unable to localize the chromosome sites of nucleolar organizer regions (NORs). Such an inadequacy is a consequence of the extensive silver and CMA3 stainability of both constitutive heterochromatin and heterochromatin associated to the NORs.

Biology of the preimaginal stages in trogid beetles (Coleoptera): Experimental data∗

Abstract Some aspects of larval behaviour in two species of trogid beetles, Trox bispidus (Pontoppidan) from temperate Europe and Afromorgus tuberosus (Klug) from tropical Africa, have been studied experimentally. From the results obtained it emerges that the rise of the newborn larvae towards the soil surface is imputable to a simple negative geotropism. Larval food relocation also contributes to reducing aggressive interactions at the food source. The potential range of trophic and behavioural variation seems to be larger than that expressed in nature as a rule. This can contribute to explaining, in evolutive terms, the rare cases of transgression from a uniform trophic and behavioural pattern, wich are probably at the origin of the evolutive success of the group as a whole.

A contribution to the knowledge of the mountain entomofauna of Mexico with a description of two new species of Onthophagus Latreille, 1802 (Coleoptera, Scarabaeidae, Scarabaeinae)

Abstract Recent intensive samplings carried out across the mountainous regions of El Pinal (Puebla, Mexico) have provided new insights into the main environmental factors that affect the geographic distribution of the scarabaeinae beetles of the Trans-Mexican Volcanic Belt above 2500 m a.s.l. This study is part of an ongoing project investigating the diversity and biogeography of copro-necrophagous beetles (Scarabaeinae, Aphodiinae, Geotrupinae and Silphidae) in the easternmost areas of the Trans-Mexican Volcanic Belt. Previous experience allows us to propose a series of predictions that we expect will provide possible explanations for current distribution patterns observed in Scarabaeinae and other groups of insects found in the Trans-Mexican Volcanic Belt. This mountain range has a primarily biogeographic importance, limiting the Mexican High Plateau in the South and connecting the western and eastern Sierra Madre mountain chains, which are considered the most important routes for dispersal of mountain fauna of northern origin. The taxonomic and biogeographic study of the species collected so far in El Pinal (including Onthophagus clavijeroi sp. n. and Onthophagus martinpierai sp. n. described here), along with their possible relationships with other known species, allows us to answer the preliminary assumptions proposed.

A taxonomic revision of the New World Onthophagus Latreille, 1802 (Coleoptera: Scarabaeidae: Scarabaeinae) of the osculatii species-complex, with description of two new species from South America

ABSTRACT The taxonomy of the osculatii complex of the hircus group is revised, with descriptions of two new species from South America (Onthophagus chacoensis sp. nov. and Onthophagus basicarinatus sp. nov.). We provide illustrated keys to the species assigned to the complex, along with descriptions and updated geographical distributions of the known Onthophagus. A neotype is designated for O. osculatii Guérin-Méneville, while lectotypes are designated for four species names. Onthophagus insularis Boheman, originally described from Tahiti, is instead considered to be an American species belonging to the osculatii complex. www.zoobank.org/urn:lsid:zoobank.org:pub:8597804C-DC30-454C-808D-DC56B0390BB7

The ninth brachypterous Onthophagus Latreille (Coleoptera: Scarabaeidae: Scarabaeinae) of the world: a new species from Mexico

ABSTRACT A new brachypterous species of Onthophagus from Mexico, belonging to the New World chevrolati species group, is described and illustrated. Illustrations of the male and female dorsal habitus, and genitalia are provided. The relationships with other brachypterous species that occur in Guerrero (Mexico) are discussed. Placement of the new species in the chevrolati group key is provided. Additionally, new locality records for O. inflaticollis Bates are provided. http://www.zoobank.org/urn:lsid:zoobank.org:pub:747118CE-6A93-401A-8625-5A75479980AD

A New Species of American Onthophagus Latreille (Coleoptera: Scarabaeidae: Scarabaeinae) Associated with Rodent (Geomyidae) Burrows

Abstract Onthophagus skelleyi Sánchez-Huerta, Zunino, and Halffter, new species, of the chevrolati species-group, hippopotamus line and complex, is described and illustrated. To the best of our knowledge, all of the species in this complex are associated with rodent (Geomyidae) burrows. The new species was found in northern Querétaro, Mexico, in the northeastern portion of the distribution area of the hippopotamus complex. The affinity of O. skelleyi with Onthophagus coproides Horn and Onthophagus hippopotamus Harold are discussed. An updated key to the species of the hippopotamus complex is also provided.

Effects of the progressive abandonment of grazing on dung beetle biodiversity: body size matters

Dung beetles are an ecologically important group of insect species inhabiting semi-natural grasslands in Europe. Despite their ecological importance, several dung beetle species are currently facing local threats mainly stemming from changes in land use practices, including the abandonment of pasturelands. The aim of this study was to analyze the impact of the progressive abandonment of grazing lands on dung beetle alpha diversity, abundance, biomass and body size classes. Areas representing a range of trophic resource availability were compared: (i) abandoned, (ii) low and (iii) moderate grazing intensity. A total of 136,884 specimens belonging to 56 species (3 Geotrupinae; 16 Scarabaeinae; 37 Aphodiinae) of dung beetle were collected. Pastureland abandonment was shown to lead to a decrease in alpha diversity and biomass density, a reduction of 22 and 78% respectively in abandoned areas. From a biomass standpoint, the effects of pastureland abandonment varied according to the body size classes of the dung beetles, with larger species proving more susceptible to local extinction. Such body-size dependent variations led us to propose the use of both biomass and abundance data in making assessments since they are differentially sensitive to trophic resource availability. Hence, from a conservationist standpoint, the obtained results suggest that traditional pastureland management with low-moderate grazing intensity should be maintained.