Explore the vast range of titles available.

The Australian fauna of Ceratocanthinae (Coleoptera, Scarabaeoidea, Hybosoridae) is revised. Two genera are present, both shared with Asia, with a total of seven species, all localized in eastern Queensland and all except one, endemic to Australia. Cyphopisthes is comprised of three species, two of them new (Cyphopisthes yorkensis sp. n. and Cyphopisthes monteithi sp. n., the latter, together with Cyphopisthes descarpentriesi Paulian, 1977 displaying an unusual ecology, with occurrence in the southern Queensland dry rainforest/scrub habitats), and Pterorthochaetes is comprised of four species, two of them new (Pterorthochaetes danielsi sp. n. and Pterorthochaeres storeyi sp. n.). Descriptions, distribution, ecological remarks and a key to species are provided.

Conglobation is an adaptive behaviour occurring independently in various animal groups. Here, we study the evolution of conglobation in Ceratocanthinae, a beetle group with the ability to roll three body segments into a tight ball. It is here implied that this ability evolved only once in the Mesozoic. Evidence is offered suggesting that the high defensive strength of Ceratocanthinae is due not only to the spherical body shape but also to the thickness and stronger mechanical properties of the dorsal cuticle. We further validate five adaptive characters including the allometrically thickened body wall and find that the specific adaptation of different body segments are likely separate evolutionary events. Finally, we propose an “attackers stress” hypothesis to explain the origin of conglobation behaviours. This work contributes to understanding how and why conglobation behaviour may have evolved in this group. Evolutionary and functional analyses alongside new fossil specimens expand our understanding of rolling-into-ball behaviour in pill scarab beetles.

The remarkable species richness of Ceratocanthinae (Coleoptera: Scarabaeoidea: Hybosoridae) found at Ulu Gombak (Selangor, West Malaysia), a secondary rainforest research station, is discussed. Eighteen species have been collected, mainly in nests of termites (Isoptera) and bess beetles (Coleoptera: Passalidae). Among them at least seven are new species, three of them here described: Madrasostes hashimi sp. n., Madrasostes mirificum sp. n., and Pterorthochaetes tsurui sp. n. Four other species (Madrasostes agostii Paulian, Madrasostes clypeale Paulian, Madrasostes depressum Paulian, and Madrasostes simplex Paulian) are recorded for the first time for West Malaysia and three for new states within West Malaysia (Pterorthochaetes insularis Gestro, Madrasostes malayanum Paulian and Madrasostes sculpturatum Paulian). A checklist of the 34 Ceratocanthinae recorded so far from West Malaysia and Singapore is provided with taxonomic, distributional and morphological remarks on some species.

Phytophagous scarab beetles associated with angiosperms have characteristically enlarged lamellate antennae and exhibit a striking morphological variation of sensilla. In this study, we compared the morphology of antennal surface of 62 species Scarabaeoidea using SEM microscopy, particularly also in light of their evolution in association with angiosperms. We investigated the correlation of antennal sensilla morphology, i.e., their structure and distribution, with species diversity and lineage diversification rates. A high diversity of sensilla was observed but also multiple transitional forms, even on the same antennomere. We interpreted this as evidence for a high evolutionary plasticity. We recognized clear patterns of convergence and repeated evolution of certain types of placoid sensilla. One main tendency found in the phytophagous Pleurostict chafers was a shift from sensilla trichodea to placoid-like sensilla, apparently also enhanced by the increase of the lamellate antennal surface, either by size or number of the lamellae. This trend occurred not only in the Pleurosticts, but also in Glaphyridae, a second angiosperm-associated lineage of Scarabaeoidea. However, our results suggest no direct relation between species diversity or the rate of diversification and general sensilla morphology, i.e., the origin of placoid sensilla. This could be explained not only by species-poor lineages also possessing placoid sensilla but also by otherwise successful and species rich groups having sensilla trichodea (e.g., dung beetles). Results further reveal the need to refine current phylogenetic hypotheses by more comprehensive taxon sampling and to expand the molecular characterization of pheromones and odor binding proteins to better understand the role of chemical communication in scarab diversification.

Modern advances in DNA sequencing hold the promise of facilitating descriptions of new organisms at ever finer precision but have come with challenges as the major Codes of bionomenclature contain poorly defined requirements for species and subspecies diagnoses (henceforth, species diagnoses), which is particularly problematic for DNA-based taxonomy. We, the commissioners of the International Commission on Zoological Nomenclature, advocate a tightening of the definition of “species diagnosis” in future editions of Codes of bionomenclature, for example, through the introduction of requirements for specific information on the character states of differentiating traits in comparison with similar species. Such new provisions would enhance taxonomic standards and ensure that all diagnoses, including DNA-based ones, contain adequate taxonomic context. Our recommendations are intended to spur discussion among biologists, as broad community consensus is critical ahead of the implementation of new editions of the International Code of Zoological Nomenclature and other Codes of bionomenclature.

Oxymorostes riedeli new genus and species is described from the Indonesian part of New Guinea. This new taxon is characterized by a number of unique characters: the presence of a deep excavation in the hypomeron and the unusually modified humeral area of the elytra. Its closest relationships seem to be within the newly defined “Perignamptus genus group”, characterized by mouthparts morphology, including the presence of a large pore on the mandibular surface. This group gathers at least the Oriental/Australasian genera Madrasostes Paulian, Perignamptus Harold, and Macrophilharmostes Paulian as well as a few species currently placed in other genera.