Abstract The monotypic genus Pilobaloderes Kulzer (Pimeliinae: Praociini), endemic to Peruvian Andes, is revised. Based on examination of recently collected specimens, we describe the female of the type species and a new species, Pilobaloderes aquilonarius sp. nov., emphasizing dimorphic and diagnostic characters of the protibiae. A redescription of the genus and its species, with remarks about sexual dimorphism are included. Habitus photographs, illustrations of protibiae, genital features, and a distribution map are also presented.

Abstract Factors influencing the diversity of tenebrionid beetles in arid, high-altitude environments in the northwest of Argentina are little-known. Using pitfall traps and suction sampling in 30 sites, we collected these beetles in Altos Andes (AA) and Puna (PU) ecoregions and evaluated how local and regional factors influenced their assemblages. During each sampling date, we registered variables related to climate, vegetation, and soil in each sampling site. In total, we recorded 270 individuals from 21 species, richness of species was higher in PU than in AA, but without a statistically significant difference. Twelve species were present exclusively in PU, while two in AA. Tenebrionid assemblages in both ecoregions had different dominant species, in PU, Psectrascelis cariosicollis while Epipedonota interandina in AA. Beta diversity between ecoregions was moderate and we recorded a high beta diversity and high turnover of species in each ecoregion. The geographical distance between the sites influenced the similarity of the assemblages inside and between ecoregions, therefore, an increase in the geographical distance between sites determined a decrease in the similarity of the assemblages. The increase in elevation of the sampled sites did not produce significant changes in the abundance and richness of Tenebrionidae. There is no individual factor responsible for the darkling beetle communities structuration in these high-altitude environments. Different combinations of both local (soil and vegetation) and regional (climate and geographical distance) environmental factors together explain the ecoregional tenebrionid assemblages. We suggest including them among the focus groups in conservation studies to evaluate anthropogenic activities in this area.

Abstract Few studies have evaluated how climate is mechanistically related to species richness in mountain environments. We used path analysis to evaluate predictions of several mechanistic hypotheses based on their hypothesized mechanism relating climate with richness of darkling beetles (Coleoptera: Tenebrionidae). We modeled the influence of spatial covariation on climatic variables and tenebrionid richness. Results showed that richness peaks at mid elevations, chiefly influenced by precipitation and temperature, both directly and indirectly through geographic range sizes. The best fitting model explains 84% of the variance of tenebrionid richness. We suggest this pattern is induced by a water-energy balance along the altitudinal gradient. At low elevations, energy availability is high but water deficit may limit species richness; in contrast, at high elevations water availability is high, but energy deficit may limit species richness. These results suggest high susceptibility of the study region to future global climate change.

Abstract Arid lands provide several products and services to humankind, but human activities affect this environment, increasing the extinction risk of the native species. Thus, to successfully conserve the biodiversity of these ecosystems, it is necessary to identify which environmental factors influence the spatial distribution of the organisms that offer these benefits. Darkling beetles play a relevant role on the functioning of deserts. Although these insects are among the most abundant and diverse in these environments, there is no agreement on the relative importance that different environmental factors have as determinants of their spatial distribution. In this work, we assessed the role of climate, vegetation, and soil variables as factors that determine distribution patterns of darkling beetles within the Natural Protected Area Península Valdés (Northeastern Patagonia). Five groups of environmental units were identified, each one with an exclusive tenebrionid species assemblage and different species diversity. The most influential environmental variables were temperature, precipitations, and soil texture. Results suggest that the magnitude of several ecosystem processes may vary among the groups of environmental units. We recommend prioritizing the conservation of the five groups of environmental units and incorporating the darkling beetles-environment relationship in future conservation strategies for arid Patagonia.

Abstract The north of Neuquén province shares with the south of Mendoza province the subprovince Payunia of the biogeographical province of Patagonic steppe, which is characterized by the presence of approximately 800 volcanoes. Although we have conducted several samplings in volcanoes of Mendoza in past years to recognize the biodiversity of tenebrionids, it is still pending which is the role that these mountains have in the biota of tenebrionids in Neuquén. In this work we reported the results of two consecutive years of prospection in two volcanoes separated by 120 km between each other, Tromen and Auca Mahuida which have 3978 and 2215 meters above sea level respectively. We found that Auca Mahuida harbours a total diversity of 10 tenebrionid species and Tromen 9, but these communities were significantly different between them. From these prospections two new endemic species of Tenebrionidae are described: Scotobius aucamahuidensis Silvestro sp. nov. (Tenebrioninae: Scotobiini) from Auca Mahuida and Psectrascelis tromensis Flores sp. nov. (Pimeliinae: Nycteliini) from Tromen. Photographs for these two new species are included, with comparisons to other known species of these genera. Based on these results we discuss the role of different factors that influence tenebrionid diversity and their implications to conserve biodiversity.

The new genus Parapraocis (Pimeliinae: Praociini) is described to accommodate three species from the northern Peruvian coast previously placed in the genus Praocis Eschscholtz: Parapraocis vagecostata (Fairmaire, 1902) n. comb. (type species), Parapraocis rossi (Kulzer, 1958) n. comb., and Parapraocis fumaria (Kulzer, 1966) n. comb. Diagnosis, description and illustrations of external morphology, male and female genitalia, and habitus photographs for two of its species are presented. A discussion on the raising of this new genus as well as homological structures in the female genitalia of the Praociini are also included.

Se describe el nuevo género Parapraocis (Pimeliinae: Praociini) para ubicar tres especies de la costa norte del Perú previamente incluidas en el género Praocis Eschscholtz: Parapraocis vagecostata (Fairmaire, 1902) n. comb. (especie tipo), Parapraocis rossi (Kulzer, 1958) n. comb. y Parapraocis fumaria (Kulzer, 1966) n. comb. Se presentan el diagnóstico, la descripción e ilustraciones de la morfología externa, genitalia masculina y femenina, y fotografías de habitus para dos de sus especies. También se incluye una discusión sobre la designación de este nuevo género, así como homologías en la morfología de los genitales femeninos de Praociini.

This contribution brings information on the type specimens of Coleoptera Tenebrionoidea deposited at the entomological collection of the Museo de La Plata (MLP). They belong to 29 species or subspecies of the families Aderidae (1 sp.), Anthicidae (11 spp.), Mordellidae (1 sp.), Oedemeridae (1 sp.), Rhipiphoridae (2 spp., 1 subsp.) and T enebrionidae of the subfamilies Alleculinae (3 spp.), Pimeliinae (5 spp., 2 subspp.) and Tenebrioninae (2 spp.). These types correspond to species described by the specialists C. Berg, C. Bruch, L. Fairmaire, M. Manfrini de Brewer, M. Pic, F. G. Werner and G. Flores. For each species we provide original and valid names, bibliographic reference, category of types, number assigned in the entomological collection of the MLP, sex (if it is indicated) and exact transcription of the labels. There is also additional information on specimens labeled as types but not having this status, because they were compared with types (19 species of Anthicidae, Ciidae, Mordellidae and Tenebrionidae Alleculinae) or corresponding to species seemingly not published.

En este trabajo se brinda información sobre los ejemplares tipo de Coleoptera, T enebrionoidea depositados en la colección entomológica del Museo de La Plata (MLP). Ellos pertenecen a 29 especies o subespecies de las familias Aderidae (1sp.), Anthicidae (11 spp.), Mordellidae (1 sp.), Oedemeridae (1sp.), Rhipiphoridae (2 spp., 1subsp.) y Tenebrionidae de las subfamilias Alleculinae (3 spp.), Pimeliinae (5 spp., 2 subspp.) y Tenebrioninae (2 spp.). Estas especies fueron descriptas por los especialistas C. Berg, C. Bruch, L. Fairmaire, M. Manfrini de Brewer, M. Pic, F. G. Werner y G. Flores. Para cada una de ellas se provee su nombre original y su nombre válido, referencia bibliográfca, categoría de tipo, número asignado en la colección entomológica del MLP, sexo (si estuviera indicado) y transcripción exacta de los datos mencionados en las etiquetas. Se mencionan además los ejemplares etiquetados como tipos, pero que no revisten la categoría de tales, por ser ejemplares comparados con los tipos (19 especies de Anthicidae, Ciidae, Mordellidae y Tenebrionidae Alleculinae), o correspondientes a especies que no estarían descriptas.

Abstract: Pitfall traps were used to study the taxonomic composition, richness, abundance, and spatio-temporal structure of the assemblage of epigean tenebrionids in continental and insular habitats of the transitional coastal desert of Chile. Samplings were conducted on the coastal area of Punta de Choros and in the Archipelago Los Choros in 2005 and 2006. A total of 982 specimens were captured, belonging to 7 tribes, 9 genera, and 17 species. The most diverse genera were Praocis Eschscholtz and Gyriosomus Guérin-Méneville. The Anosim analysis showed statistically-significant differences between seasons (R = 0.31; p = .01) but not among habitats (R = 0.1872; p = .12), although the effect of these factors was low. The highest richness and diversity was observed in the interior coastal steppe and the coastal steppe of Los Choros, whereas the highest abundance occurred in the interior coastal steppe (26.5%). Seasonal structure was not observed; however, the data showed increased abundance in spring both in the continent and on the islands, with the exception of Choros island, where the highest abundance occurred in winter. This paper discusses the differences in the soil and plant characteristics of the ecosystems under study.

Resumen: Se estudió la composición taxonómica, riqueza, abundancia y estructura espacio-temporal del ensamble de tenebriónidos epigeos en diferentes hábitats continentales e insulares del desierto costero transicional de Chile. Los muestreos se realizaron en el borde continental de Punta de Choros y en el archipiélago de Los Choros durante los años 2005 y 2006 mediante el uso de trampas de intercepción. Se capturó un total de 982 individuos pertenecientes a 7 tribus, 9 géneros y 17 especies, siendo Praocis Eschscholtz y Gyriosomus Guérin-Méneville los géneros más diversos. Se realizó el análisis Anosim que encontró diferencias significativas entre estaciones (R = 0.31; p = 0.01) pero no entre hábitats (R = 0.1872; p = 0.12), aunque con un bajo efecto de estos factores. La mayor riqueza y diversidad se observó en los hábitats estepa costera interior y estepa costera Choros, mientras que la mayor abundancia se registró en estepa costera interior (26.5%). No se observó una estructura estacional, pero los datos mostraron una mayor abundancia en primavera tanto en el continente como en las islas, a excepción de la isla Choros, donde la mayor abundancia se registró en invierno. Se discuten estas diferencias en relación con las características pedológicas y vegetacionales de los ambientes estudiados.

The introduction of domestic livestock in the arid Patagonia produced changes in vegetation and soil that altered fundamental ecosystem processes, increasing desertification and biodiversity loss. In this region, it is common to observe gradients of decreasing animal activity from watering points where livestock impact is greatest near the watering sites, called piospheres, particularly suitable for assessing the efect of grazing on arid ecosystems. The aim of this study was to evaluate the efect of sheep-grazing intensity using piospheres on the structure of the vegetation and soil in shrubby steppes of Peninsula Valdes, Argentina. Variation of plant cover, vertical complexity of the vegetation, number and area of vegetated patches, micro-topography and soil compaction in relation to piosphere gradients were studied using Generalized Linear Mixed Models (GLMM) and multivariate analyses. Grazing intensity decreased according to increasing distance to the watering point. This fact, explaining more than 50% of the overall environmental variability, confirmed the existence of a piosphere gradient on each studied site. Such environmental changes were characterized by a gradual increase in grass and litter cover, vertical complexity of vegetation and soil microtopography at increasing distances from the watering point. Percentages of bare soil and gravel, cover of annual grasses and soil compaction showed the opposite pattern. This study demonstrates, for the first time, the existence of sheep piospheres in the shrubby steppes of Peninsula Valdes. Our results indicate that sheep-grazing intensity is associated with changes in the structure and composition of the vegetation and the soil characteristics that are compatible with degradation processes in the study region. Taking into account the importance of Peninsula Valdes in the context of biodiversity conservation, more studies of this type are required to implement efective management actions integrating livestock and conservation eforts on the terrestrial ecosystems of the region.

La introducción de ganado doméstico provocó modificaciones en la vegetación y en el suelo de la Patagonia extra-andina. Estos cambios alteraron procesos ecosistémicos, aumentaron la desertificación y causaron pérdida de biodiversidad. Es frecuente encontrar gradientes decrecientes de actividad animal partiendo de las aguadas (piósferas), que resultan adecuados para determinar el impacto del pastoreo sobre los ecosistemas. El objetivo de este estudio fue evaluar el efecto de la intensidad de pastoreo ovino a partir de gradientes de piósfera sobre la estructura de la vegetación y el suelo en estepas arbustivas representativas de Península Valdés, Argentina. Mediante modelos lineales generalizados mixtos (GLMM) y técnicas multivariadas se estudiaron las variaciones en la cobertura vegetal, complejidad vertical de la vegetación, número y área de parches vegetados, microtopografía del suelo y su compactación en relación con el gradiente de pastoreo. La intensidad del pastoreo disminuyó con la distancia a la aguada y explicó más de 50% de la variabilidad ambiental. Esto demuestra la existencia de efecto piósfera. La cobertura de herbáceas, mantillo, complejidad vertical de la vegetación y la microtopografía aumentaron al disminuir la presión de pastoreo en los sitios más alejados de la aguada, mientras que el porcentaje de suelo desnudo, gravas, cobertura de anuales y la compactación del suelo presentaron un patrón opuesto. Este estudio evidencia, por primera vez, la existencia de piósferas ovinas en Península Valdés e indica que la intensidad de pastoreo en la región se asocia con alteraciones ambientales compatibles con procesos importantes de degradación ecosistémica. Dada la importancia que reviste la península en el contexto de la conservación biológica de la región, se requieren más estudios de este tipo para una implementación efectiva de medidas de manejo que integren la ganadería y la conservación de los recursos naturales.

The Neotropical genus Scotobius Germar (Tenebrioninae: Scotobiini) comprises 61 species distributed from central Peru and southern Brazil to southern Argentine and Chile. In this contribution two species of Scotobius: S. punctatus Eschscholtz, 1831 and S. andrassyi Kaszab, 1969, that inhabit in western San Juan, Mendoza, and Neuquén provinces (Argentina) and in central Chile, along the “Cordillera de los Andes” and extra-Andean mountains in Argentina, are revised. Redescriptions using new morphological data and photographs of habitus and pronota are provided. This article informs about the geographic distribution, altitudinal ranges and the biogeographic provinces that these species inhabit. A predictive model of species distribution is presented to propose hypothesis about the factors that influence the space distribution and the allopatry of these two species.

El género neotropical Scotobius Germar (Tenebrioninae: Scotobiini) comprende 61 especies distribuidas desde el centro de Perú y sur de Brasil hasta el sur de Argentina y Chile. En este trabajo, revisamos dos especies de Scotobius que habitan el oeste de las provincias de San Juan, Mendoza y Neuquén (Argentina) y en Chile central, a lo largo de la Cordillera de los Andes y las montañas extra-andinas en Argentina: S. punctatus Eschscholtz, 1831 y S. andrassyi Kaszab, 1969. Se proveen redescripciones utilizando nuevos caracteres morfológicos y se proporcionan fotografías de los adultos y de los pronotos. Se consigna la distribución geográfica, rangos altitudinales y las provincias biogeográficas en las que habitan estas especies. Se utiliza un modelo predictivo de distribución de especies para proponer hipótesis sobre los factores que influencian la distribución espacial y que explicarían la alopatría de ambas especies.

The Choros Archipelago includes three islands: Choros, Damas and Gaviota and it is part of The Pingüino de Humboldt National Reserve. These insular ecosystems are within the Chilean transitional coastal (25°-32° S). Prior researches in the archipelago reported a species of Tenebrionidae (Coleoptera) endemic to Choros island (29°15' S, 71°32' W) described as Gyriosomus granulipennis Pizarro-Araya & Flores. The objective of this paper is to evaluate the vulnerability of this species in the archipelago through Conservation Priority Index (CPI), Environmental Ministery of Chile (MMA) and Red List of IUCN. We concluded that G. granulipennis is Endangered by CPI index, and Vulnerable by MMA of Chile. Additionally, this species can be classiffied with Deficient Data (DD) by IUCN because many of data are impossible or difficult to obtain for insects and can overestimate or underestimate the risk of extinction of this species. We consider important to monitoring the continuity of this species and the protection of habitat, for which we propose not allow access the tourists and eradication of European rabbit.

El archipiélago de Los Choros, conformado por las islas Choros, Damas y Gaviota forma parte de la Reserva Nacional Pingüino de Humboldt y está situado dentro del desierto costero transicional de Chile (25°-32° S). Estudios recientes realizados en el archipiélago dan cuenta de una especie endémica de Tenebrionidae (Coleoptera) de la isla Choros (29°15' S, 71°32' O) descripta como Gyriosomus granulipennis Pizarro-Araya & Flores. El objetivo del presente trabajo es evaluar la prioridad de conservación de esta especie en el archipiélago mediante el análisis del Índice de Prioridad de Conservación (CPI), clasificación del Ministerio de Medio Ambiente (MMA) de Chile y lista roja de la IUCN. Nuestros resultados sostienen que esta especie puede ser catalogada en categoría En peligro por el índice CPI y Vulnerable según el MMA. Según criterios IUCN esta especie debería ser categorizada con Datos Deficientes (DD), ya que muchos de los datos necesarios para la clasificación son difíciles de obtener para insectos o pueden sobrestimar o subestimar el riesgo de extinción de esta especie. Consideramos importante monitorear la continuidad de esta especie y conservarla a través del hábitat, para lo cual proponemos evitar el acceso a turistas y erradicar el conejo silvestre europeo.

We conducted a study of the biogeographic patterns of epigean tenebrionids (Coleoptera: Tenebrionidae) that inhabit the Protected Natural Area Península Valdés (Chubut, Argentina), based on data obtained from collections and collecting trips. We present a comprehensive species list, where we detail the degree of adaptation to aridity shown by each species, an analysis of the quality of the inventory, an estimation of total species richness, and an evaluation of distribution and richness patterns, with the identification of areas of significantly greater richness or "hotspots". The results indicated that 25 species with different degrees of adaptation to aridity inhabit the peninsula, although it was estimated that the total richness of the area should be 27 species. In addition, it was recognized that the species range sizes follow a log-normal distribution and that only three species are endemic. The spatial distribution of richness was aggregate within the peninsula and we can identify 10 "hotspots". Finally, considering that in the Península Valdés are allowed productive activities that cause significant habitat degradation, we discuss the implicances that have these findings for epigean tenebrionids conservation.

Se realizó un estudio sobre los patrones biogeográficos de los tenebriónidos epigeos (Coleoptera: Tenebrionidae) que habitan el Área Natural Protegida Península Valdés (Chubut, Argentina), basado en datos de colecciones y material recolectado en viajes a la zona. Se presenta una lista exhaustiva de las especies en la que se consigna el grado de adaptación a la aridez de cada una de ellas; un análisis de la calidad del inventario y la estimación de la riqueza total de especies; una evaluación de los patrones de distribución y riqueza, y la identificación de áreas de significativa mayor riqueza o hotspots. Los resultados indicaron que 25 especies con diferente grado de adaptación a la aridez habitan la península, aunque se estima que la riqueza total del área debería ser de 27. Además, se reconoció que los rangos de distribución de los tenebriónidos siguen una distribución log-normal y que sólo 3 especies son endémicas. Espacialmente, la riqueza se distribuyó de forma agregada en la península y se determinaron 10 hotspots. Finalmente, considerando que en la península Valdés están permitidas actividades productivas que originan una importante degradación del hábitat, se examina la implicancia de los resultados para la conservación de los tenebriónidos epigeos.

Various studies have shown that model performance may vary depending on the species being modelled, the study área, or the number of sampled localities, and suggest that it is necessary to assess which model is better for a particular situation. Thus, in this study we evalúate the performance of different techniques for modelling the distribution of Patagonian insects. We applied eight of the most widely used modelling methods (artificial neural networks, BIOCLIM, classification and regression trees, DOMAIN, generalized additive models, GARP, generalized linear models, and Maxent) to the distribution of ten Patagonian insect species. We compared model performance with five accuracy measures. To overeóme the problem of not having reliable absence data with which to evalúate model performance, we used randomly selected pseudo-absences located outside of the polygon área defined by taxonomic experts. Our analyses show significant differences among modelling methods depending on the chosen accuracy measure. Maxent performed the best according to four out of the five accuracy measures, although its accuracy did not differ significantly from that obtained with artificial neural networks. When assessed on per species basis, Maxent was also one of the strongest performing methods, particularly for species sampled from a relatively low number of localities. Overall, our study identified four groups of modelling techniques based on model performance. The top-performing group is composed of Maxent and artificial neural networks, followed closely by the DOMAIN technique. The third group includes GARP, GAM, GLM, and CART, and the fourth best performer is the BIOCLIM technique. Although these results may allow obtaining better distributional predictions for reserve selection, it is necessary to be cautious in their use due to the provisional nature of these simulations.

Varios estudios han mostrado que el desempeño de los modelos de distribución puede variar dependiendo de la especie modelizada, el área de estudio o el número de localidades de presencia utilizadas, sugiriendo que es necesario evaluar cuál es la mejor técnica de modelización en cada situación concreta. En este estudio evaluamos distintas técnicas de modelización para la distribución de los insectos patagónicos. Hemos aplicado ocho de los métodos más ampliamente usados (redes neuronales, BIOCLIM, árboles de clasificación y regresión, DOMAIN, Modelos Aditivos Generalizados, GARP, Modelos Lineares Generalizados y Maxent) a los datos de distribución de diez especies de insectos patagónicos, comparando su efectividad mediante cinco medidas diferentes. Para evitar el problema de la carencia de datos de ausencia fiables con los que evaluar los modelos, hemos utilizado pseudoausencias seleccionadas al azar fuera de un área poligonal definida por taxónomos expertos. Nuestros análisis muestran diferencias significativas entre los distintos métodos de modelización dependiendo de la medida de validación utilizada. Maxent es el método que ofrece mejores resultados para cuatro de las cinco medidas de validación utilizadas, aunque su precisión no difiere de la obtenida con redes neuronales. Cuando se examina la efectividad para cada una de las especies, Maxent resultó también uno de los métodos más fiables, especialmente en el caso de aquellas especies con un pequeño número de localidades. En conjunto, este estudio identifica cuatro grupos de técnicas de modelización. El de mayor fiabilidad sería el compuesto por Maxent y las redes neuronales, seguido de cerca por DOMAIN. El tercer grupo incluiría GARP, GAM, GLM y CART, mientras que el cuarto estaría formado por BIOCLIM. Aunque estos resultados pueden permitir obtener mejores predicciones de distribución con capacidad para ser utilizadas en la planificación de reservas, es necesario ser cauto en su utilización debido a la naturaleza provisional de estas simulaciones.