Edilson Caron

Beetles are recognized for their ability to inhabit a wide range of environments, including subterranean habitats, where they have achieved notable ecological success. In Brazil, research on beetle fauna has increased substantially, however this trend does not extend to cave-dwelling species. Staphyliniform beetles are no exception, and current knowledge of their subterranean representatives remains limited. To address this gap, the present study describes two new taxa from the same Brazilian cave. One of these is a new species of Plagiogramma Tarsia in Curia, 1935 (Histeridae, Tribalinae), while the second taxon is the second species of the genus Tavakilianidia Orousset, 1985 (Staphylinidae, Osoriinae). For both taxa, this study represents the first record of these genera in cave environments and, for Tavakilianidia , the first record in Brazil. Plagiogramma unicum Leivas, sp. nov ., resembles P. amplistria Kovarik & Dégallier, 2021, but differs in its smaller size, light brown coloration, body dorsally and ventrally finely and sparsely punctate, reduced eyes, fronto-clypeal region strongly concave, a carinal striae of the prosternal keel that divergent anteriorly and subparallel posteriorly, and an indistinct median metaventral suture. Tavakilianidia flava Caron, sp. nov . differs from T. anophtalma Orousset, 1985 in having a lighter body, antennomeres 4–6 not pedicellate, and a perfectly globose spermatheca. These findings increase the known diversity of these previously neglected beetle groups in Brazil and provide new insights into the biology of their genera.

Hypotelus monnei Paiva & Caron sp. nov., is a new species of minute rove beetles (Coleoptera: Staphylinidae, Piestinae) described from Brazil. We have also added the new species to the dichotomous key of Hypotelus Erichson, 1839 and verified the monophyly of the genus, now including the new species. Hypotelus monnei sp. nov. is similar to H. corniculatus Bortoluzzi & Caron, 2017, but differs by having the head distinctly darker than the pronotum, frontal processes one-fourth to one-third the length of the antennal scape, antenna shorter than that of H. corniculatus with antennomere IV subquadrate, and sternite VIII with sinuous posterior margin. The new species shares morphological characters with four species that comprise a clade previously referred to as Clade C. Until now, the species of this clade were distributed from Costa Rica to Brazil and concentrated in tropical rainforests. The new species represents the southernmost and easternmost distribution of Clade C, and is the first species of this clade to occur in Brazil. With this addition, Brazil now records three species of Hypotelus.

Platyprosopini Lynch, 1884 comprises a single genus, Platyprosopus Mannerheim, 1830, whose species exhibit a nearly worldwide distribution. Members of the genus are consistently collected in proximity to rivers or other humid environments. In the present study, we describe two species, including one new species, and provide the first investigation of a set of openings on the abdomen of Platyprosopus. In both P. parallelus Sharp and P. metaxyus sp. nov., we observed three openings situated at the base of tergites and sternites. No internal reservoir was detected, but a reinforced muscular system associated with the openings was present, and a cluster of cells adjacent to the basal insertions is presumed to function in glandular secretion. Because the biology of the genus and the chemical composition of the glandular secretions remain unknown, the function of the openings cannot yet be inferred.

The Atlantic Forest is one of the most biodiverse biomes in the world. A significant protected area in Paraná State (Brazil) represents an ecotone between two subdivisions: the Upper Paraná Atlantic Forest and the Araucaria Moist Forest. This protected area experiences a loss of approximately half of its canopy tree leaves between June and August, leading to the formation of a thick layer of leaf litter. This environment fosters a high abundance and diversity of Staphylinidae beetles, the beetle family with the highest species richness, particularly in the Neotropics. This study investigated whether soil characteristics influence Staphylinidae composition and diversity. Among the two soil types analyzed, Ultisol exhibited the highest overall richness (63 morphospecies) and diversity, whereas Oxisol (38 morphospecies) hosted a compositionally distinct community with greater internal variability, a pattern consistent across years. A generalized linear model confirmed soil type as the main predictor of richness, while NMDS ordination showed distinct community clustering by soil type, corroborated by PERMANOVA. These results infer the importance of Ultisol within the reserve, given that it is subject to greater disturbance through direct contact with crops and highways. Demonstrating the importance of soil properties in biodiversity monitoring enhances the understanding of habitat heterogeneity and reinforces the relevance of soil health.

Parasitoids of the genus Aleochara play an important role in the natural regulation of cyclorrhaphous Diptera of medical and veterinary relevance, many of which are associated with decomposing substrates and are of forensic importance. Aleochara (Aleochara) lustrica Say, 1832 (Coleoptera: Staphylinidae) is distributed across the Americas but, despite records from several Brazilian states, had not previously been reported from Rio Grande do Sul, and its host associations remain poorly documented. In this study, we report the first occurrence of A. (A.) lustrica in Rio Grande do Sul, Brazil, extending its known southern distribution limit in the Americas. Field sampling was conducted between April and May 2025 at the Pelotas – Visconde da Graça Campus (IFSul), using poultry liver as bait to attract ovipositing flies. Pupae recovered from the substrate were reared individually under controlled laboratory conditions. Among 178 field-collected sarcophagid pupae, 61 (34.26%) were parasitized, yielding nine adult specimens of A. (A.) lustrica. Although parasitized puparia were morphologically highly consistent with Microcerella halli (Engel, 1931) (Diptera: Sarcophagidae), species-level host identification for field-parasitized pupae could not be formally confirmed and is therefore conservatively interpreted at the family level (Sarcophagidae). Laboratory assays confirmed M. halli as a suitable host for A. (A.) lustrica, representing the first confirmed association between this parasitoid and a sarcophagid fly under controlled conditions. These findings expand current knowledge of the geographic distribution and host range of A. (A.) lustrica and document a previously unreported interaction of relevance to ecological, veterinary, and forensic entomology.

Piestinae are flat rove beetles found under tree bark, in rotting wood and, occasionally, in leaf litter. Siagonium Kirby & Spence, 1815 is an extant genus of Piestinae with species in the Holarctic region. The main objective of this study was to test the monophyly of Siagonium and to investigate its relationship with the other genera of Piestinae. Twenty-four terminal taxa and 51 morphological characters were used in the analyses. Siagonium is paraphyletic, and forms a clade with Piestoneus Sharp, 1889. Siagonium + Piestoneus is supported by eight synapomorphies, two of which are non-homoplastic. We synonymize Piestoneus , including its four species, with Siagonium . The current Southeast Asia was indicated as the ancestral range for Siagonium. Dispersal and vicariance events are discussed, including the Beringian bridge. Additionally, the genus is redescribed and illustrated, and a checklist is provided.

The interaction between exotic African mahogany species (Khaya spp.) and their associated insects in Brazilian plantations holds scientific and economic significance, and Brazil hosts one of the largest cultivated areas of these trees worldwide. The most widely planted species in the country, Khaya grandifoliola, has often been misidentified as Khaya ivorensis, causing confusion in the literature and compromising entomological research and pest management efforts. We also found several misidentifications of associated insects in the literature, further complicating the understanding of these interactions. While studies typically focus on the mahogany shoot borer (Hypsipyla grandella), records of numerous other insects reported by growers remain unpublished or are linked to incorrect tree species names. This reveals a critical knowledge gap, with few studies accurately documenting insect occurrences or confirming their pest status. This review article compiles and analyzes the current literature on insects associated with African mahogany in Brazil, contributing to the taxonomic and ecological understanding of these interactions. The findings provide a foundation for sustainable plantation management and improved pest management, offering guidance to researchers and producers involved in African mahogany cultivation.

Hypotelus Erichson is a genus of minute rove beetles widely distributed in Central and South America. The species were recently revised and the monophyly of the genus was confirmed based on morphological data. We describe a new species from Ecuador, provide scanning electron microscope images to demonstrate the diagnostic characteristics of the genus and include the new species in a dichotomous key. We also reassess the monophyly of the genus, now including the new species, using morphological and molecular data combined. Hypotelus chusqueaticus sp. nov. is similar to H. testaceus, but differs by having elytra unicolored, male sternite 8 with posterior margin somewhat pointed and female sternite 8 with posterior margin projected in middle-third. Including the new species, Hypotelus is confirmed as a monophyletic group with three internal clades. The new species is closely related to H. marginatus.

The genus Macrotrichurus Silvestri (Coleoptera: Staphylinidae: Aleocharinae: Termitonannini) is composed of two species that are associated with termite nests of the genera Anoplotermes Müller, Cornitermes Wasmann and Orthognathotermes Holmgren, from southeastern Brazil. In this paper, we describe Macrotrichurus granzottorum Da-Silva, Caron & Moreno sp. nov., from southwestern Brazil from nests of Patawatermes turricula (Silvestri), representing a novel host record for the genus. Additionally, we provide an updated taxonomic key for Macrotrichurus species, a revised diagnosis for the genus, notes on behavior, and discussion about hosts. This research extends the known distribution of the genus to the state of Mato Grosso do Sul.

The Museu de Zoologia da Universidade de São Paulo (MZUSP) houses one of the most extensive collections of zoology in Latin America. Its type collection of Staphylinidae includes items identified by nearly 30 entomologists, such as Charles Seevers, Erich Wasmann, Lubomir Hromádka, Max Bernhauer, Otto Scheerpeltz, and Thomas Borgmeier. This catalog details every type specimen of Staphylinidae housed at MZUSP. The collection spans more than 2,300 type specimens, including secondary types, from nearly 200 species and eight subfamilies. About 70% of the species are primary types, with 77% originating from Brazil. Thomas Borgmeier is the most represented taxonomist, accounting for 34% of the species with types at MZUSP, followed by Max Bernhauer and Charles Seevers. We offer details on the labels and photos of the dorsal aspect of all types, and the labels of at least one specimen from each species. Furthermore, we detail specimens labeled as types that have not yet been officially recognized as such.