Passalid (Insecta: Coleoptera: Passalidae) collected from trunks of Scleronema micranthum (Malvaceae) / Passalídeos (Insecta: Coleoptera: Passalidae) coletados em troncos de Scleronema micranthum (Malvaceae)

Some beetles can attack the wood immediately after the tree is felled, but there are those that start their attack at different stages of wood degradation. Beetles of the family Passalidae belong to this latest category. The objective of this study was to assess the occurrence of beetles of this family in wood samples taken from trunks of Scleronema micranthum, a forest species from Central Amazon. The samples were exposed to biodegradation for 24 months on the forest ground of the Experimental Station of Tropical Silviculture of the National Institute for Amazonian Research, in Manaus, Amazon State, Brazil. During that period, 15 samples were removed from the experiment, every two months, for insect collection and evaluation of infestation. The presence of six species was recorded, all of them of the Passalini tribe: Passalus (Pertinax) latifrons, P. (Passalus) variiphyllus, P. (Pertinax) convexus, P. (Passalus) interstitialis, P. (Passalus) lanei, and Paxillus leachi. Among these species, P. (Passalus) interstitialis was the most abundant, with 18 individuals. This species was the first one to infest the samples and was found between the eighth and twentieth month of the experiment. The infestation occurred predominantly in the bark and sapwood.

Alguns besouros atacam a madeira imediatamente após o abate da árvore, enquanto outros preferem a madeira em diferentes estágios de degradação. Nesta categoria estão inseridos os besouros da família Passalidae. O objetivo deste estudo foi avaliar a ocorrência de besouros dessa família em amostras provenientes de troncos de Scleronema micranthum, espécie florestal da Amazônia Central. As amostras ficaram expostas à biodegradação durante 24 meses no solo da floresta da Estação Experimental de Silvicultura Tropical do Instituto Nacional de Pesquisas da Amazônia, em Manaus, Amazonas, Brasil. Durante esse período, a cada dois meses, 15 amostras foram removidas da floresta para a coleta desses insetos e avaliação da infestação. Foi registrada a presença de seis espécies, todas da tribo Passalini: Passalus (Pertinax) latifrons, P. (Passalus) variiphyllus, P. (Pertinax) convexus, P. (Passalus) interstitialis, P. (Passalus) lanei e Paxillus leachi. Dentre as espécies, P. (Passalus) interstitialis foi a mais abundante, com 18 indivíduos; foi a primeira a infestar as amostras e foi registrada entre o oitavo e o vigésimo mês do experimento. A infestação ocorreu predominantemente na casca e alburno da madeira.

Morfoecología de gremios en escarabajos (Coleoptera: Passalidae) en un gradiente altitudinal en robledales de la Cordillera Oriental, Colombia / Morphoecology guild in beetles (Coleoptera: Passalidae) along an altitudinal gradient in oak forests of the Eastern Cordillera, Colombia

ResumenLos escarabajos pasálidos son componentes importantes de los bosques tropicales debido a que facilitan el reciclaje de nutrientes propios de madera en descomposición, ya sea por acción directa (consumo) o indirecta (facilitando la acción de otros organismos). En la actualidad los estudios ecológicos dentro del grupo son escasos y se han centrado en respuestas a cambios ambientales relacionados con su recurso alimenticio. En el presente estudio se caracterizó la composición gremial de escarabajos pasálidos, distribuida en un gradiente altitudinal, de acuerdo a sus características de aprovechamiento del recurso. Se cuantificaron aspectos morfoecológicos de importancia adaptativa para la explotación diferencial del recurso (medidas corporales, puntos homólogos en cuerpo y alas y series de Fourier en protibias). Se reconocieron cinco especies, 198 grupos familiares y tres gremios: el subcortícola, el alboduramícola y el generalista. La riqueza de la comunidad disminuyó conforme aumentó la altitud. Los cambios entre las variables morfométricas lineales se vieron influenciadas por la altitud; por su parte, los datos morfogeométricos se comportaron independientes del gradiente. El análisis de marcadores morfológicos (morfogeométrico) arrojó información relevante para la delimitación de los gremios ya establecidos en esta familia. Dentro de estos, la forma general del cuerpo junto a las tibias anteriores, aportaron la mayor información de agrupación gremial. La cuantificación de dichos marcadores evidenció la relación entre los tipos de aprovechamiento del recurso, ya que al ser estructuras importantes en el movimiento y consumo de la madera en microzonas particulares, permite plantear roles funcionales puntuales. Reconocer estas variables en interacción con aquellas ecológicas brinda herramientas para el entendimiento de la riqueza y los aportes funcionales de los escarabajos pasálidos al ecosistema.

AbstractBess beetles are important components on tropical forest dead wood nutrient cycling, since they act as direct consumers and ease the consumption by another organism (indirect). Studies of bess beetle ecology are scarce and have focused on communities responses to environmental changes on alimentary resources. We characterized the bess beetles guild composition in an elevation gradient, according to their differential use of resources (microhabitat) and morphological traits quantification (geometric and lineal), as a potential tool to improve our understanding on resource use and functional ecology of beetles. Three guilds (underbark, sapwood-heartwood and generalists feeders), five species and 198 familiar groups were recognized; their richness decreased as elevation increased. Changes in linear morphometric measures were influenced by elevation; morphogeometrical measures were not associated with the elevation gradient, only grouping at guild level were observed. Morphological markers analysis (morphometric) provided information to guild delimitation. Body and metatibiae shape contributed with the best information to guild grouping. Quantification of those structural markers proved the relationship between resource repartition, because they are involved in movement on wood galleries and wood consumption, this fact allowed to propose specific functional roles. The identified patterns have contributed on the understanding of functional processes in Passalidae communities and their role in ecosystem function.

Coadaptación entre los ácaros (Arachnida: Klinckowstroemiidae) y coleópteros Passalidae (Insecta: Coleoptera) / Co-adaptation between mites (Arachnida: Klinckowstroemiidae) and Passalidae beteles (Insecta: Coleoptera)

Co-adaptation between mites (Arachnida: Klinckowstroemiidae) and Passalidae beteles (Insecta: Coleoptera). Mites of the family Klinckowstroemiidae establish an association with beetles of the family Passalidae known as phoresy. In order to obtain information about this association, we analyzed the relationship between mites of the family Klinckowstroemiidae and beetles of the family Passalidae, as adult mites have been exclusively collected from host beetles. We examined 1 150 beetles collected in seven states of the Mexican Republic, and found 19 species of klinckowstroemiid mites associated with 168 passalids, that belong to 28 different species in 15 genera. Host specificity between species of both groups does not exist, as one species of passalid beetle can have several different symbionts; conversely, a given mite species can associate with passalid beetles of different species and even of different genera. This way, Odontotaenius zodiacus has been found associated with mites of seven species of the genus Klinckowstroemia. Besides, Klinckowstroemia valdezi is associated with five species of passalids. Furthermore, two and even three different species of mites have been found on one host beetle (synhospitality). The lack of congruence between the phylogenies of the mites and that of the beetles indicates that a process of co-adaptation by colonization is going on, because the association is due to the resources that passalid beetles can offer to the mites, like transportation, food and refuge. Since these resources are not host-specific, the klinckowstroemiid mites can climb onto virtually any species of passalid beetles occurring on the same habitat. Rev. Biol. Trop. 60 (2): 599-609. Epub 2012 June 01.

Realizamos un análisis de la relación que existe entre los ácaros Klinckowstroemiidae y los coleópteros Passalidae, puesto que los ácaros adultos se recolectaron exclusivamente sobre pasálidos (huéspedes). Asimismo, examinamos 1 150 coleópteros recolectados en siete estados de la República Mexicana, y encontramos 19 especies de ácaros klinckowstroémidos asociados con 168 de ellos, pertenecientes a 28 diferentes especies de 15 géneros distintos. Estos táxones establecen una relación simbiótica llamada foresia. No existe una especificidad entre las especies de ambos grupos, debido a que una especie de pasálido puede tener varios forontes, y una especie de ácaro puede asociarse a pasálidos de diferentes géneros y especies. Un ejemplo es Odontotaenius zodiacus que presentó a siete especies de Klinckowstroemia asociadas, y por otro lado, Klinckowstroemia valdezi se encuentra asociada a cinco especies de pasálidos. Además, dos o hasta tres especies de ácaros se encontraron sobre un coleóptero huésped (synhospitality). La falta de congruencias entre la filogenia de los ácaros con la de los pasálidos nos indica que se está produciendo un proceso de coadaptación por colonización, y que ésta asociación se debe a los recursos que le brindan los pasálidos a los ácaros: transporte, refugio y alimento. Como estos recursos no son específicos para algún huésped los klinckowstroémidos se suben a cualquier especie de pasálido.

Pseudoscorpionida (Arachnida) em galerias de colônias de Passalidae (Coleoptera, Insecta) em troncos caídos em floresta de terra firme da Amazônia, Brasil / Pseudoscorpionida (Arachnida) found in the galleries made by Passalidae (Coleoptera, Insecta) colonies inside fallen wood of the Amazonian terra firme forest, Brazil

Em sete municípios do Amazonas, um de Rondônia e um de Roraima, foram examinadas 71 colônias de 24 espécies de Passalidae (Coleoptera), pertencentes aos gêneros: Passalus Fabricius, 1792 (14 espécies); Paxillus Mac Leay, 1819 (três); Popilius Kaup, 1871 (três); Spasalus Kaup, 1869 (uma); Verres Kaup, 1871 (uma); Veturius Kaup, 1871 (duas). Foram registradas doze espécies de pseudoscorpiões, incluindo nove gêneros e cinco famílias, listadas a seguir: Chernetidae - Americhernes aff. incertus Mahnert, 1979, Cordylochernes scorpioides (Linnaeus 1758), Lustrochenes similis (Balzan 1892), L. aff. reimoseri Beier, 1932, L. intermedius (Balzan 1892), Phymatochernes crassimanus Mahnert 1979; Chthoniidae - Pseudochthonius homodentatus Chamberlin, 1929; Lechytiidae - Lechytia chthoniiformis (Balzan 1887); Tridenchthoniidae - Tridenchthonius mexicanus Chamberlin & Chamberlin 1945; Withiidae - Cacodemonius sp., Dolichowithius (D.) emigrans (Tullgren 1907), D. (D.) mediofasciatus Mahnert, 1979. Dentre as espécies mais freqüentes (T. mexicanus, L. intermedius e L. aff. reimoseri), ocorreram todos os estágios de desenvolvimento. Foram coletadas de uma a três espécies de pseudoscorpiões em cada colônia individual de besouros passalídeos. T. mexicanus foi a única espécie encontrada em todos os municípios, ocorrendo em 45 colônias de dezenove espécies de passalídeos, sendo a maioria dos exemplares encontrado no subcórtex. L. intermedius foi a segunda espécie mais abundante, ocorrendo em colônias de 11 espécies de Passalidae, a maioria também no subcórtex. L. aff reimoseri ocorreu em 13 colônias de Passalidae, sob a casca, alburno e cerne. L. aff. reimoseri foi a única espécie coletada somente no cerne.

Seventy-one colonies from 24 species of Coleoptera, Passalidae, belonging respectively to the genera Passalus Fabricius, 1792 (14 species), Paxillus Mac Leay, 1819 (three species), Popilius Kaup, 1871 (three species), Spasalus Kaup, 1869 (one species), Verres Kaup, 1871 (one species) and Veturius Kaup, 1871 (two species), were examined from seven municipalities of Amazonas, one of Rondônia and one of Roraima states. Twelve species of psedoscorpions were found, belonging to nine genera and five families, as follows: Chernetidae - Americhernes aff. incertus Mahnert 1979, Cordylochernes scorpioides (Lin. 1758), Lustrochenes similis (Balzan 1892), L. aff. reimoseri Beier, 1932, L. intermedius (Balzan 1892), Phymatochernes crassimanus Mahnert 1979; Chthoniidae - Pseudochthonius homodentatus Chamberlin 1929; Lechytiidae - Lechytia chthoniiformis (Balzan 1887); Tridenchthoniidae - Tridenchthonius mexicanus Chamberlin & Chamberlin 1945; Withiidae - Cacodemonius sp, Dolichowithius emigrans (Tullgren 1907), D. mediofasciatus Mahnert, 1979. Among the most common species, all the development stages of T. mexicanus, L. intermedius and L. aff. reimoseri were found. From one to three species of pseudoscorpions were collected in each colony of passalíd beetles. T. mexicanus, the only species found in all municipalities, was caught in 45 colonies of nineteen species of passalids, the majority of them occurring under bark. L. intermedius, the second most abundant species, was caught in colonies of 11 species of passalids, the majority of them also under bark. Lustrochenes aff. reimoseri was caught in colonies of 13 species of Passalidae under bark and in sapwood and heartwood and was the only species caught exclusively in heartwood.

A new Paxillus MacLeay, 1819 (Coleoptera: Passalidae: Passalinae) from the state of Amazonas, Brazil / Um novo Paxillus MacLeay, 1819 (Coleoptera: Passalidae: Passalinae) do Estado do Amazonas, Brasil

Paxillus is a neotropical genus belonging to the subfamily Passalinae widespread from Mexico to Argentina. Brazil is known to harbor five species belonging to this genus with most of them presenting at head a flattened central tubercle lacking a free apex. However, one of these species, Paxillus macrocerus Reyes-Castillo & Fonseca, differs from that pattern by having a long central tubercle with a completely free apex. The present study describes and illustrates another new species, which has been found in the Brazilian Amazon, showing this same characteristic.

Paxillus é um gênero neotropical pertencente à subfamília Passalinae, distribuído do México até a Argentina. No Brasil são conhecidas cinco espécies desse gênero, a maioria delas apresentando um tubérculo central achatado sem ápice livre. Entretanto, uma dessas espécies, Paxillus macrocerus Reyes-Castillo & Fonseca, apresenta um padrão diferente, tendo em vista que possui um tubérculo central longo com o ápice completamente livre. O presente estudo descreve e ilustra outra espécie nova, a qual foi encontrada na Amazônia brasileira, que apresenta essa mesma característica.