Although insects are fundamental to understanding and conserving global biodiversity, they are vastly understudied. Here, we present a national inventory of Costa Rican insects based upon 3.78 million DNA barcodes representing 152 891 Barcode Index Numbers (BINs, proxies for species) from 28 localities sampled from 2017 to 2023 through the national BioAlfa program of Costa Rica. Although only 3.6% of BINs are linked to Linnean species, barcode-based community analyses revealed strong, consistent ecogeographic structure. Clustering of BIN data using bootstrapped Jaccard distances revealed seven distinct mainland assemblages and a distinct island cluster, shaped primarily by Costa Rica’s mountain ranges, elevation, and slope orientation. Separate analyses for Coleoptera, Diptera, Hemiptera, Hymenoptera, and Lepidoptera coupled with analyses focused on some of their largest families (e.g., Braconidae, Cecidomyiidae, Cicadellidae, Erebidae, and Staphylinidae) confirmed these patterns and further revealed extremely high species turnover with most BINs being exclusive to a single region or locality. Our results reveal limited overlap of insect communities across ecosystems, implying that each life zone harbors unique taxonomic assemblages. Large-scale DNA barcoding has detected fine-grained spatial structure, providing a genomic framework for biodiversity monitoring and conservation in diverse tropical regions undergoing rapid environmental change.

We report fungal species used as food sources by mycophagous scarab beetles, with special emphasis on Phanaeus MacLeay, 1819, and confirm that Phanaeus zapotecus Edmonds, 2006 and Phanaeus bravoensis Moctezuma, Sánchez-Huerta & Halffter, 2017 are mycophagous. Mycophagy is confirmed in the P. endymion and P. tridens species groups. We propose a vicariant speciation process for the mycophagous species of the P. endymion species group (P. halffterorum Edmonds, 1979; P. zapotecus; and P. bravoensis) in the mountains of central Mexico, driven by competition, glaciation-induced climatic change, biome and faunal shifts, and access to a new food resource (fleshy fungi) in a new environment (pine–oak forest). We reiterate the revalidation of Phanaeus dionysius Kohlmann, Arriaga-Jiménez & Rös, 2018 as a distinct species and confirm its coprophagous habits. Based on morphological characteristics, we establish the Phanaeus halffterorum species complex within the Phanaeus endymion species -group.

This analysis evaluates the characters, methods, and classifications used in the taxonomy of the "Canthonina" group (Coleoptera: Scarabaeidae: Scarabaeinae: Deltochilini) by historical taxonomy systematists and assesses the evolutionary relationships proposed at generic and subgeneric levels. Two parsimony analyses generated by this study using traditional morphological characters were compared with current phylogenetic views of Deltochilini (Coleoptera: Scarabaeidae: Scarabaeinae). The following taxonomic changes are clarified: Holocanthon Martínez & Pereira, 1956 is confirmed as a member of Deltochilini. Melanocanthon Halffter, 1958 and Bajacanthon Halffter, 2022 are synonymized with Boreocanthon Halffter, 1958, which is now reinstated at the generic level. Pseudocanthon is restored to genus rank. The following genera are reaffirmed as removed from Deltochilini and placed into incertae sedis: Agamopus Bates, 1887; Canthochilum Chapin, 1934; Canthonella Chapin, 1930; Cryptocanthon Balthasar, 1942; Paracanthon Balthasar, 1938; Sinapisoma Boucomont, 1928; Streblopus Lansberge, 1874a; and Zonocopris Arrow, 1932. Provisional phylogenetic hypotheses for Canthotrypes, Pseudocanthon, and Vulcanocanthon are presented. According to this study Deltochilini contains 446 described species across 21 genera in the Americas. This work offers a comprehensive view of the systematics and evolutionary relationships of Deltochilini based on historical morphological characters, making it the most taxonomically inclusive analysis of this tribe to date.

A biodiversity and distribution analysis of the beetle families Bolboceratidae and Geotrupidae, and the subfamily Scarabaeinae (Scarabaeidae) of Honduras is presented for the first time. The checklist contains 98 species: two Bolboceratidae, one Geotrupidae, and 95 Scarabaeinae. The fauna of Honduras includes two genera of Bolboceratidae, one genus of Geotrupidae, and 22 of Scarabaeinae. Onthophagus is the most speciose genus, with 21 species, followed by Canthon (10 species) and Copris (9 species). Valid names and synonyms are provided. First country records, notes on presently recognized species, distribution maps, and biodiversity comparisons are included, and nomenclatural problems associated with species in question are discussed. Phanaeus lempira Kohlmann, Solís and Rivera, sp. nov. (Coleoptera: Scarabaeidae) is described as a new species. Canthon sallei Harold, 1863 and Canthon spinosus Harold, 1863 are reinstated as valid species. Canthon cyanellus LeConte, 1859 does not contain any subspecies. Two new synonymies are established: Canthon cyanellus violetae Halffter, 1961, syn. nov. of Canthon sallei Harold, 1863; Canthon speciosus Harold, 1868, syn. nov. of Canthon spinosus Harold, 1863.

Three new species assigned to the satanas species-group of Dichotomius Hope (Coleoptera: Scarabaeidae: Scarabaeinae) are described from North and Central America: Dichotomius pisuicas Solís and Kohlmann, new species, from the Caribbean slope of Honduras to Panama; D. lucifer Solís and Kohlmann, new species, from the Costa Rican and Panamanian Pacific rainforests; and Dichotomius chamuco Solís and Kohlmann, new species, from Mexico to Honduras. A description, diagnosis, images, and distributional map are presented for each species.

Species groups of Western Hemispheric Onthophagus Latreille (Coleoptera: Scarabaeidae: Scarabaeinae: Onthophagini) are suggested using COI barcoding and gene trees and supported by congruence with external morphology, behavior, ecology, and biogeographic evidence. New species groups, complexes, and taxonomic statuses are offered, and other preexisting proposals are confirmed. No barcoding gap w as found between the intragroup and intergroup genetic distance blocks, but the average intragroup (8.38%) and intergroup (13.88%) Kimura-two-parameter distances are statistically different. The following seven preexisting species groups were supported by the congruence between the mtDNA barcode analysis and other independent evidence: O. chevrolati, O. clypeatus, O. dicranius, O. gazellinus, O. hircus, O. landolti, and O. mexicanus. Eight new species groups are suggested: O. crinitus, O. curvicornis, O. eulophus, O. hecate, O. hoepfneri, O. marginatus, O. nasutus, and O. velutinus. Possible behavioral/ecological adaptations of morphological characters are also discussed. New biogeographic and evolutionary hypotheses are also advanced. An identification key for species groups is presented.

Costa Rica emerged from the seas as a new geological territory during the Miocene as an insular archipelago. It later became part of a continental area once it became a segment of Central America. Two dung beetle genera that colonized this new territory from South and North America, Canthidium and Onthophagus (Coleoptera: Scarabaeidae: Scarabaeinae), are here studied, in the first analysis of a volcanic paleo-archipelago, colonized from its emergence, and then later becoming terra firma. To assess their biodiversity distribution patterns, we analyzed the effect of biogeography, ecosystem origins, and body size on their altitudinal distribution patterns in three geographic basins of Costa Rica. Based on 32 years of collecting representing more than 158,000 specimens from 1017 localities, we undertook Generalized Linear Models of the two dung beetle genera to assess the effects of biodiversity and biogeographical distribution patterns. Canthidium and Onthophagus species ranged from 0 to 3000 m a.s.l., with an abrupt diversity decline at altitudes above 1500 m. Endemic species tended to show a higher altitudinal mean with a narrow altitudinal band distribution than non-endemic dung beetle species. Although there was a trend of decreasing species body size with the increase in altitude, such a trend depended on the distribution pattern of the species group. This possible insular-mediated endemicity mechanism has generated baffling biodiversity levels, considered the highest worldwide per unit area. Costa Rica is an expanse represented by a geographic overlap of two or more temporally disjunct areas and is not part of a natural transition zone. The effect of the insular Miocene origin of Costa Rica still pervades today, reflected by different insular syndromes shown by the dung beetle fauna. The importance of geological origins in generating biodiversity seems to have been an underrated criterion for conservation biology practices and should be considered ex officio. In Costa Rica, Canthidium and Onthophagus have abrupt diversity declines above 1500 m a.s.l. Endemic species showed narrower vertical distribution when compared to non-endemic ones.image

Costa Rica emerged from the seas as a new geological territory during the Miocene as an insular archipelago. It later became part of a continental area once it became a segment of Central America. Two dung beetle genera that colonized this new territory from South and North America,

Costa Rica emerged from the seas as a new geological territory during the Miocene as an insular archipelago. It later became part of a continental area once it became a segment of Central America. Two dung beetle genera that colonized this new territory from South and North America, Canthidium and Onthophagus (Coleoptera: Scarabaeidae: Scarabaeinae), are here studied, in the first analysis of a volcanic paleo-archipelago, colonized from its emergence, and then later becoming terra firma. To assess their biodiversity distribution patterns, we analyzed the effect of biogeography, ecosystem origins, and body size on their altitudinal distribution patterns in three geographic basins of Costa Rica. Based on 32 years of collecting representing more than 158,000 specimens from 1017 localities, we undertook Generalized Linear Models of the two dung beetle genera to assess the effects of biodiversity and biogeographical distribution patterns. Canthidium and Onthophagus species ranged from 0 to 3000 m a.s.l., with an abrupt diversity decline at altitudes above 1500 m. Endemic species tended to show a higher altitudinal mean with a narrow altitudinal band distribution than non-endemic dung beetle species. Although there was a trend of decreasing species body size with the increase in altitude, such a trend depended on the distribution pattern of the species group. This possible insular-mediated endemicity mechanism has generated baffling biodiversity levels, considered the highest worldwide per unit area. Costa Rica is an expanse represented by a geographic overlap of two or more temporally disjunct areas and is not part of a natural transition zone. The effect of the insular Miocene origin of Costa Rica still pervades today, reflected by different insular syndromes shown by the dung beetle fauna. The importance of geological origins in generating biodiversity seems to have been an underrated criterion for conservation biology practices and should be considered ex officio.

Costa Rica emerged from the seas as a new geological territory during the Miocene as an insular archipelago. It later became part of a continental area once it became a segment of Central America. Two dung beetle genera that colonized this new territory from South and North America, Canthidium and Onthophagus (Coleoptera: Scarabaeidae: Scarabaeinae), are here studied, in the first analysis of a volcanic paleo‐archipelago, colonized from its emergence, and then later becoming terra firma. To assess their biodiversity distribution patterns, we analyzed the effect of biogeography, ecosystem origins, and body size on their altitudinal distribution patterns in three geographic basins of Costa Rica. Based on 32 years of collecting representing more than 158,000 specimens from 1017 localities, we undertook Generalized Linear Models of the two dung beetle genera to assess the effects of biodiversity and biogeographical distribution patterns. Canthidium and Onthophagus species ranged from 0 to 3000 m a.s.l., with an abrupt diversity decline at altitudes above 1500 m. Endemic species tended to show a higher altitudinal mean with a narrow altitudinal band distribution than non‐endemic dung beetle species. Although there was a trend of decreasing species body size with the increase in altitude, such a trend depended on the distribution pattern of the species group. This possible insular‐mediated endemicity mechanism has generated baffling biodiversity levels, considered the highest worldwide per unit area. Costa Rica is an expanse represented by a geographic overlap of two or more temporally disjunct areas and is not part of a natural transition zone. The effect of the insular Miocene origin of Costa Rica still pervades today, reflected by different insular syndromes shown by the dung beetle fauna. The importance of geological origins in generating biodiversity seems to have been an underrated criterion for conservation biology practices and should be considered ex officio.

Abstract Elevational gradients are excellent models to understand species distribution across sites with marked shifts in environmental conditions. In northern South America, tepuis are table-top mountains with elevations above 1000 m and high biodiversity and endemism levels. In this study, we assessed the effect of elevation on dung beetle (Coleoptera: Scarabaeidae: Scarabaeinae) assemblage structure (species richness, abundance, and biomass) in Tepequém, a tepui located in northern Brazil. Dung beetles were sampled with pitfall traps within seven elevational bands from 250 to 850 m. A total of 83 individuals from 14 species were collected, Oxysternon festivum (Linnaeus, 1758) and an unidentified Onthophagus species being the most abundant. Elevation did not affect beetle species richness and biomass. However, species composition from 750 to 850 m differed statistically from that recorded at lower elevations. Our results suggest that beetle assemblages possess a bimodal distribution along an altitudinal gradient on the Tepequém. The contrasting vegetation structure of tepuis between highlands (shrubland savannah vegetation) and lowlands (tropical rainforest) explains the different composition of the assemblages. This study should be considered as a starting point in improving our understanding of the dung beetle diversity of tepuis, which present a unique singular relationship between elevation and species diversity.

Se presenta una revisión histórica del proceso de clasificación y el desarrollo de la sistemática de los Lamellicornia o Scarabaeoidea (Insecta: Coleoptera), dividida en tres períodos. El análisis comprende un estudio histórico-comparativo sobre el desarrollo del tipo y número de caracteres, así como el número y características de los géneros y agrupamientos en taxones supragenéricos. El primer período abarca 14 autores en diferentes fechas, iniciando en 1735 con Linné y terminando en 1856 con Lacordaire. En este período se abordan trabajos anteriores a la publicación del “Origen de las Especies”, por lo cual las ideas evolucionistas darwinianas no tuvieron influencia sobre la sistemática del grupo. En el segundo período se presenta una comparación de las propuestas de clasificación de los Coleoptera Scarabaeoidea, publicadas entre 1869 y 1955 por 17 autores de trabajos faunísticos y taxonómicos regionales o en catálogos mundiales. Se destacan los principales caracteres morfológicos utilizados para la separación supragenérica y las inovaciones introducidas por cada uno de ellos, señalando en su caso, la posible influencia de las teorías de Darwin. Se concluye que el esquema general de clasificación durante este período no cambió substancialmente con respecto al de Burmeister o Lacordaire, y que las ideas evolucionistas tuvieron poca repercusión en estas clasificaciones, las cuales son más complejas que las del primer período, sobre todo por la adición de más de 11,000 especies nuevas obtenidas durante 80 años de exploraciones mundiales. En el tercer período se resumen y analizan las propuestas de clasificación publicadas entre 1957 y 2001 por 28 autores de monografías, estudios faunísticos y claves regionales, artículos sobre morfología comparativa, y trabajos expresamente enfocados al esclarecimiento de las relaciones filéticas y los procesos evolutivos de los Scarabaeoidea en conjunto, o por grupos supragenéricos particulares de esta superfamilia. En la mayor parte de estos estudios es evidente la influencia de las teorías sobre la evolución orgánica, y se observa como progresivamente se busca que las clasificaciones reflejen las relaciones entre sus elementos, principalmente a través de enfoques feneticistas y cladistas.

Several studies have tested the Elevational Rapoport Rule (ERR) in arthropods, especially in the Neotropical mountains. Nonetheless, different approaches should be used for a more nuanced comprehension of ERR patterns and assemblage altitudinal distribution patterns, such as the biogeographical, ecological, and evolutionary contexts. This study aims to test the ERR for elevational gradients in Mexican mountains. For this study, dung beetle assemblages of the genus Onthophagus were used as a model organism, and their distribution was studied in several different mountain ranges of the Mexican tropics. Altitudinal distribution of Onthophagus species was analyzed, including ecological traits and biogeographical/phylogenetical contexts as covariables. The increase of altitude was positively correlated to the assemblage altitudinal range. Furthermore, altitudinal range, relative abundance, body size, and mountain’s topographic prominence were positively correlated to the mean altitudinal range of Onthophagus species. Nonetheless, different altitudinal relationships were observed, depending on the mountain. The results support the idea that species that inhabit higher altitudes appear to be more environmentally plastic and occur in wider altitudinal ranges than species from lower altitudes, thus supporting the ERR. The present findings stress that biogeographical, ecological, phylogenetical, and historical aspects, besides body size, are essential drivers of the altitudinal distribution of Onthophagus dung beetles.

Biomass is the primary source of energy for cooking in rural Central America. The intensity of labour required to collect wood, levels of pollution resulting from incomplete burning, health problems linked to smoke inhalation, and pressure on forests are among the problems commonly associated with cooking with traditional stoves utilized in the region. Since the 1980s, improved stoves programs have been implemented in the region, but exogenous-developed models have had low adoption rates due to a lack of know-how for construction and repairments, expensive materials, and lack of understanding of local culinary traditions and culture. Sustainable Harvest International (SHI), a non-profit organization, has successfully developed two local improved stoves: the Damak model in Panama and the Mani model in Honduras. In both cases, anecdotal evidence of high rates of long-term adoption has been noted by SHI. Nonetheless, before this study, there has been no systematic evaluation of the efficiency of these two models in respect to 1) daily household wood consumption (kg); 2) particulate matter (PM 2.5 ug/m 3 ) concentration in the kitchen, and 3) carbon monoxide (CO ppm) concentration in the kitchen when compared to the traditional stoves used in rural households of both countries. The results presented herein were generated from a study using a random representative sample of 174 stoves and a portable Indoor Air Pollutant Meter manufactured by Aprovecho Research Center (ARC). An analysis of variance processed the data under the general and mixed model frameworks. The results showed that there was a statistically significant average decrease in wood consumption per day per stove for the improved models, as well as a statistically significant average decrease in personal exposure to particulate matter and carbon monoxide for the improved models when compared to those self-same measurements generated by traditional stoves.