RESUMEN Se presenta una revisión taxonómica del género Scolia Fabricius, 1775 (Hymenoptera: Scoliidae) de América Central. Dos especies de Scolia están presentes en América Central: S. (Discolia) guttata Burmeister, 1853 y S. (Hesperoscolia) rufiventris Fabricius, 1804, esta última representa el primer registro para Costa Rica, Panamá y Colombia. El macho de S. rufiventris se describe e ilustra por primera vez. Se describe la actividad estacional de vuelo para S. guttata a partir de dos años de captura continua con trampas Malaise en la isla de Barro Colorado, Panamá.

ABSTRACT A taxonomic revision of the genus Scolia Fabricius, 1775 (Hymenoptera: Scoliidae) from Central America is presented. Two species of Scolia are present in Central America: S. (Discolia) guttata Burmeister, 1853 and S. (Hesperoscolia) rufiventris Fabricius, 1804, the latter representing the first record for Costa Rica, Panama and Colombia. The male of S. rufiventris is described and illustrated for the first time. Seasonal flight activity for S. guttata from two years of continuous Malaise trapping in Barro Colorado Island, Panama, is described.

Resumen Introducción: Ephuta es un género de avispas mutílidas ampliamente distribuido en el Nuevo Mundo y cuya ecología es poco conocida. Objetivo: El objetivo de este trabajo fue determinar cómo varía la abundancia de especies de Ephuta anualmente y estacionalmente debido a las condiciones climáticas y sus hospederos. Métodos: Se examinaron especímenes de Ephuta tomados de muestras semanales (2001-2006) de diez trampas Malaise, ubicadas en el “bosque viejo” de Isla Barro Colorado. La abundancia mensual de cada especie de Ephuta se comparó con el promedio mensual de la humedad, la radiación solar, la temperatura y las precipitaciones. Resultados: Se identificaron nueve especies y diez morfoespecies. La mayoría de los especímenes fueron recolectados de marzo a junio. La mayor abundancia mensual promedio se dio en abril. De las cuatro variables abióticas medidas, solo la temperatura mensual promedio se correlacionó con la abundancia de Ephuta. Los meses con el mayor número de especímenes de Ephuta se correlacionan con la sospechosa abundancia del huésped, como lo indica la abundancia mensual de Pompilidae (Hymenoptera) capturada durante el 2007. Conclusiones: Ephuta muestra una fuerte variación estacional en la abundancia, con picos durante el final de la estación seca y el comienzo de la temporada de lluvias. Esta se correlaciona ampliamente con la temperatura y la abundancia de sus huéspedes pompílidos.

Abstract Introduction: Ephuta Say is a widespread New World genus of mutillid wasp whose ecology is poorly understood. Objective: The objective of this study was to determine how Ephuta species abundance varies annually and seasonally driven by weather conditions and hosts. Methods: Ephuta specimens, located in the “old forest” at Barro Colorado Island, were examined from weekly samples (2001-2006) of ten Malaise traps. The monthly abundance of each Ephuta species was compared with monthly average humidity, solar radiation, temperature and rainfall. Results: Nine species and ten morphospecies were identified. Most specimens were collected from March to June. April was the month reported with the greatest abundance. Of the four abiotic variables measured, only average monthly temperature was correlated with Ephuta abundance. Months with the highest number of Ephuta specimens were correlated with suspected host abundance, as indicated by the monthly abundance of Pompilidae (Hymenoptera) captured during the year 2007. Conclusions: We concluded that Ephuta display strong seasonal variation in abundance, with the peaks occurring during the end of the dry season and beginning of the rainy season, which correlate broadly with temperature and the abundance of their pompilid hosts.

Se han propuesto muchos modelos para explicar la coexistencia de una alta diversidad de especies de árboles en bosques tropicales. Prominente, entre estos modelos es el de Janzen-Connell, que sugiere que los herbívoros especialistas limitan la colonización de árboles en función de la densidad o proximidad de con-específicos. Si este efecto es en realidad el resultado de ataque por herbívoros, debiera haber heterogeneidad espacial en la herbivoría. Aquí se evalúa esta hipótesis estudiando la distribución espacial de la herbivoría en juveniles de seis especies comunes de Inga (Fabaceae: Mimosoideae) en la parcela de 50ha de la Isla de Barro Colorado, en Panamá. Análisis de autocorrelación espacial no mostraron heterogeneidad en la herbivoría de estas especies, y la densidad local de con-específicos, congéneres o confamiliares no se correlacionó con la herbivoría de las plantas estudiadas. Solo una de las especies de estudio sufrió mortalidad densidad-dependiente en 20 años de censos. Aunque muchos estudios han demostrado que los efectos densidad-dependientes en la mortalidad de las plantas son comunes en bosques tropicales, nuestro entendimiento de los mecanismos que causan esos efectos es aún limitado, y la suposición de que estos resultan de heterogeneidad espacial en el ataque de herbívoros merece más escrutinio.

Many models have been proposed to explain the possible role of pests in the coexistence of a high diversity of plant species in tropical forests. Prominent among them is the Janzen-Connell model. This model suggests that specialized herbivores and pathogens limit tree recruitment as a function of their density or proximity to conspecifics. A large number of studies have tested the predictions of this model with respect to patterns of recruitment and mortality at different life stages, yet only a few have directly linked those density or distance-dependent effects to pest attack. If pest-attack is an important factor in density or distance-dependent mortality, there should be spatial heterogeneity in pest pressure. I studied the spatial distribution of leaf damage in saplings of six common Inga species (Fabaceae: Mimosoideae) in the 50ha forest dynamic plot of Barro Colorado Island, Panama. The percent leaf damage of Inga saplings was not heterogeneous in space, and the density of conspecific, congener or confamilial neighbors was uncorrelated with the observed damage levels in focal plants. One of the focal species did suffer density-dependent mortality, suggesting that spatial variation in plant performance in these species is not directly driven by leaf damaging agents. While multiple studies suggest that density-dependent effects on performance are common in tropical plant communities, our understanding of the mechanisms that drive those effects is still incomplete and the underlying assumption that these patterns result from differential herbivore attack deserves more scrutiny.

Cololejeunea panamensis G. Dauphin & Pócs, descrita em 2006 foi referida como endêmica para a ilha de Barro Colorado no Panamá, América Central. Durante um estudo sobre a brioflora da ilha do Marajó, uma espécie de Cololejeunea mostrou-se diferente das espécies já registradas no Brasil, provando ser uma nova ocorrência para a América do Sul. O objetivo desse trabalho é divulgar a ocorrência dessa espécie em território brasileiro e ampliar o conhecimento sobre sua distribuição geográfica, morfologia e ecologia. O material estudado foi coletado na ilha do Marajó, município de Soure, estado do Pará, Brasil, no período de 10 a 16 de Janeiro de 2007. As amostras coletadas estão depositadas no Herbário do Museu Paraense Emílio Goeldi (MG). Foram coletadas um total de nove amostras contendo Cololejeunea panamensis, sendo esse o segundo registro já feito da espécie além do material tipo e o primeiro registro para a América do Sul. A espécie é descrita taxonomicamente, ilustrada e são feitos comentários sobre a distribuição geográfica, variação morfológica e habitat.

Cololejeunea panamensis G. Dauphin & Pócs was described in 2006 and cited as endemic to Barro Colorado Island in Panama, Central America. During a study on the bryophytes of Marajó Island, one of the Cololejeunea collected showed differences from the species recorded in Brazil, proving to be a new record for South America. The aim of this study is to report the occurrence of this species in Brazil and discuss its geographic distribution, morphology and ecology. The material studied was collected on Marajó Island, municipality of Soure, Para state, Brazil, from 10 to 16 January 2007. The collections are deposited in the herbarium of Museu Paraense Emílio Goeldi (MG). We sampled nine collections containing Cololejeunea panamensis. This is the second record for C. panamensis after the type collection and the first record in South America. The species is described taxonomically, illustrated and comments on geographic distribution, morphology and habitat are presented.

Los desplazamientos del ámbito hogareño de mamíferos subadultos previos a la dispersión natal rara vez han sido documentados. Sin embargo, los eventos que llevan a un animal subadulto a abandonar una parte de su ámbito natal, antes de buscar un sitio definitivo donde reproducirse, pueden estar relacionados con las causas de la dispersión en si. En este estudio, utilizamos una combinación de radio-telemetría manual y un Sistema de Radio-Telemetría Automatizado para estudiar de manera continua los movimientos de un ocelote (Leopardus pardalis) macho subadulto, un carnívoro solitario con dispersión sesgada sexualmente, en la Isla de Barro Colorado, Panamá, durante 18 meses (mayo 2003 hasta octubre 2004). Los padres del ocelote subadulto también fueron monitoreados por radio-telemetría para registrar posibles interacciones entre padres e hijo en sus ámbitos hogareños. A la edad aproximada de 21 meses, el ocelote subadulto comenzó a desplazar gradualmente su ámbito hogareño natal, estableciendo uno nuevo que fue ocupado hasta el final del estudio, en un área que había sido ocupada previamente por otro macho subadulto en dispersión. Se registraron solamente tres interacciones entre padres e hijo en los cuatro meses del desplazamiento. La aparente naturaleza pacífica de estos encuentros, junto con el lento abandono de una parte de su ámbito hogareño natal, sugieren que el subadulto no fue expulsado de su área natal por sus padres. El momento del desplazamiento, junto con el incremento en peso del subadulto (al peso propio de un adulto) cuatro meses después de haber establecido su nuevo territorio, sugiere que los desplazamientos del ámbito hogareño previos a la dispersión natal podrían actuar como una estrategia oportunista y de bajo riesgo para alcanzar el tamaño adulto, minimizando la competencia con padres y hermanos, en preparación para una dispersión final a un nuevo territorio para reproducirse.

Home range shifts prior to natal dispersal have been rarely documented, yet the events that lead a subadult to abandon a portion of its home range and venture into unfamiliar territories, before eventually setting off to look for a site to reproduce, are probably related to the causes of dispersal itself. Here, we used a combination of manual radio-tracking and an Automated Radio Telemetry System to continuously study the movements of a subadult male ocelot (Leopardus pardalis), a solitary carnivore with sex-biased dispersal, on Barro Colorado Island, Panama, for 18 months from May 2003 through October 2004. The subadult ocelot’s parents were also radio-tracked to record possible parent-offspring interactions within their home ranges. At the age of ca. 21 months the subadult gradually began to shift its natal home range, establishing a new one used until the end of the study, in an area that had previously been used by another dispersing subadult male. Only three parent-offspring interactions were recorded during the four months around the time the range-shift occurred. The apparent peaceful nature of these encounters, along with the slow transition out of a portion of his natal home range, suggest the subadult was not evicted from his natal area by his parents. The timing of the shift, along with the subadult’s increase in weight into the weight range of adult ocelots four months after establishing the new territory, suggests that predispersal home range shifts could act as a low risk and opportunistic strategy for reaching adult size, while minimizing competition with parents and siblings, in preparation for an eventual dispersal into a new breeding territory. Rev. Biol. Trop. 56 (2): 779-787. Epub 2008 June 30.

Comparamos características físicas de raíces aéreas de la palmera Socratea exorrhiza en sitios inclinados (pendiente>20º) y sitios planos, en dos lugares neotropicales. S. exorrhiza (n=80 árboles) no muestra diferencias en el número de raíces, la altura vertical de las raíces, la circunferencia y la masa del cono de las raíces, o la posición de las raíces en los sitios con pendiente. Encontramos relaciones positivas entre el crecimiento vertical y la arquitectura de las raíces aéreas, incluso entre el número de raíces, la circunferencia del cono de las raíces, y la masa del cono de las raíces. Es posible que las raíces aéreas permitan a S. exorrhiza crecer en altura y mantener la estabilidad mecánica sin involucrar el diámetro del tallo y la estructura de las raíces subterráneas. Probablemente, esta estrategia incrementa la capacidad de la especie para usar claros de luz rápidamente, en comparación con palmeras carentes de raíces aéreas; posiblemente también exista un incremento en su supervivencia cuando las adultas palmeras se acercan a sus límites de estabilidad mecánica.

Arboreal palms have developed a variety of structural root modifications and systems to adapt to the harsh abiotic conditions of tropical rain forests. Stilt roots have been proposed to serve a number of functions including the facilitation of rapid vertical growth to the canopy and enhanced mechanical stability. To examine whether stilt roots provide these functions, we compared stilt root characteristics of the neotropical palm tree Socratea exorrhiza on sloped (>20º) and flat locations at two lowland neotropical sites. S. exorrhiza (n=80 trees) did not demonstrate differences in number of roots, vertical stilt root height, root cone circumference, root cone volume, or location of roots as related to slope. However, we found positive relationships between allocation to vertical growth and stilt root architecture including root cone circumference, number of roots, and root cone volume. Accordingly, stilt roots may allow S. exorrhiza to increase height and maintain mechanical stability without having to concurrently invest in increased stem diameter and underground root structure. This strategy likely increases the species ability to rapidly exploit light gaps as compared to non-stilt root palms and may also enhance survival as mature trees approach the theoretical limits of their mechanical stability. Rev. Biol. Trop. 55 (3-4): 787-793. Epub 2007 December, 28.

Cerceris é um gênero bastante interessante, cujas espécies estão presentes em todos os continentes, em diferentes condições climáticas, mostrando comportamentos variando do solitário ao social. Com relação ao hábito de nidificação desse gênero, muitos autores descreveram as características do ninho e das presas, provendo material útil para comparações. Além disso, a maioria das espécies estudadas até agora vivem em regiões temperadas e faltam informações sobre as tropicais. O grande número de espécies e sua ampla distribuição sugerem uma adaptabilidade filogenética que merece ser estudada mais profundamente. Neste trabalho foram investigados o ninho e a presa da espécie tropical Cerceris binodis Spinola, no Barro Colorado Natural Monument no Panamá. O estudo foi realizado durante três estações secas, marcando e escavando os ninhos, observando o comportamento dos indivíduos e coletando a presa. Os ninhos, reutilizados na mesma estação e nos anos seguintes, são especialmente profundos, como observados somente em outra espécie neotropical, Cerceris lutzi Scullen. Esse resultado pode ser correlacionado com a profundidade de solos tropicais e suas características. Apesar de as espécies apresentarem dimorfismo sexual, as celas subterrâneas não mostram diferenças no tamanho ou no seu conteúdo. A presa, identificada dos espécimes carregados pelas fêmeas provedoras, pertencem a Clytrinae (Coleoptera: Chrysomelidae). Os dados quantitativos sobre a presa foram analisados por comparação das estações e locais, evidenciando as diferenças. Infere-se que a adaptabilidade de Cerceris às características ecológicas dos trópicos pode explicar essas diferenças assim como as observadas na estrutura do ninho.

Cerceris is a very interesting genus, providing species living in all continents, in different climatic conditions, showing behaviors ranging from solitary to social. About the nesting habit of this genus, many authors described nest characteristics and prey, providing useful material for comparison. Yet, the majority of species studied so far live in temperate regions and we lack information about the tropical ones. The high number of species and their wide distribution suggest a phylogenetic adaptability that merit to be studied deeper. I investigated nest and prey of a tropical species, Cerceris binodis Spinola, on Barro Colorado Nature Monument in Panamá. The study was performed during three dry seasons, marking and excavating nests, observing individual's behavior and collecting prey. The nests, reused over the same season and in following years, are especially deep as observed only in another neotropical species, Cerceris lutzi Scullen . This result could be correlated with tropical soils depth and characteristics. In spite of the species being sexually dimorphic, the subterranean cells show no bimodality in size or content. Prey, identified from specimens carried by provisioning females, belongs to Clytrinae (Coleoptera: Chrysomelidae). Quantitative data on prey are analyzed comparing seasons and sites and differences emerged. Cerceris adaptability to ecological trait of the tropics is inferred to explain these differences as well as the ones observed in the nest structure.

Se exploró el ajuste a corto plazo en la eficiencia fotosintética (Fv /Fm )en hojas jovenes y adultas del arbusto del sotobosque neotropical Psychotria limonensis Krause (Rubiaceae)en respuesta a cambios rápidos de luz ambiental. Las hojas fueron recolectadas de 20 plantas individuales bajo condiciones de sol y sombra en Peninsula Gigante, Monumento Natural Barro Colorado (Panamá),durante la estación lluviosa de 1996.Las hojas fueron distribuidas en una secuencia cuatro tratamientos de luz (AB las hojas fueron expandidas bajo el sol y fueron transferidas a la sombra,BA las hojas experimentaron la transferencia contraria,y las hojas controles AA y BB que fueron expandidas y mantenidas bajo condiciones de sol o de sombra).Las hojas adultas o jóvenes no difieren en la eficiencia fotoquímica general.Por el contrario,se encontró diferencias entre los ambientes de luz (iluminados), para los cuales las hojas transferidas de la sombra al sol mostraron las menores tasas Fv /Fm .No hubo relación entre la eficiencia fotoquímica y la temperatura de las hojas. En P.limonensis ,las plantas son suceptibles a la foto -inhibición independientemente del estado ontogenético de la hoja. El enfoque utilizado en este experimento permitió la rápida exploración de esta capacidad y demostró que puede ser utilizado en otras especies poco estudiadas del sotobosque.

We explored the short-term adjustment in photochemical efficiency (Fv /Fm )in adult and young leaves of the understory neotropical shrub Psychotria limonensis Krause (Rubiaceae)in response to rapid changes in the light environment.Leaves were collected from 20 individual plants growing under sun and shade conditions on Gigante Peninsula,Barro Colorado Natural Monument (Republic of Panama),during the wet season of 1996. Leaves were distributed in four sequences of light treatments (AB leaves were expanded under sun and were transferred to shade,BA leaves experienced the opposite transfer,and the controls AA and BB leaves that were expanded and maintained under sun or shade conditions).Adult and young leaves did not differ in overall photochemical efficiency.Instead,differences were found among light environments,for which leaves transferred from shade to sun showed the lowest F v /F m ratios.There was no relationship between photochemical efficiency and leaf temperature.In P.limonensis,understory plants are susceptible of photoinhibition independently of the leaf ontogenetic stage.The approach utilized in this experiment allowed the rapid exploration of this capacity, and could be applied to poorly studied understory species. Rev.Biol.Trop.52(4):839-844.Epub 2005 Jun 24.

Se estudió la distribución, mortalidad, reclutamiento y asociación con plantas, de 308 nidos de la hormiga neotropical Paraponera clavata en una parcela de cincuenta hectáreas de bosque viejo en la isla de Barro Colorado entre septiembre de 1993 y febrero de 1995. Los nidos estaban distribuidos uniformemente a través de toda la parcela, y se asociaban de manera significativa con el tipo de hábitat, existían más nidos de los esperados en las planicies altas y en la sección de bosque más joven de la parcela. La densidad promedio era de 6.2 nidos por hectárea. Los nidos con un mayor número de vecinos entre 0 y 20 m de distancia, tenían una mayor probabilidad de morir, si se comparaban con aquéllos que se encontraban separados por distancias mayores. La mortalidad era entre 13.36 y 69.64% dependiendo del intervalo de censo, y el reclutamiento fue del 22.63 y 31.72%. Los nidos se encontraron en las bases de 84 especies de plantas, en 34 familias con cuatro categorías de forma de vida: 76 especies eran árboles, 5 especies eran arbustos, 2 especies eran palmas y 1 era liana. Ocho especies de plantas se asociaban positivamente con los nidos de la hormiga. Plantas medianas entre 8 y 63.9 cm de DAP eran las más utilizadas. Arboles y arbustos pequeños presentan muy poca asociación con los nidos. La hormiga no se asocia con árboles que tienen nectarios extraflorales. El 53% de los nidos tenían a Phrynus gervaisii (Amblypygi: Phrynidae) habitando en el interior. Estos nidos presentaron menores tasas de mortalidad en comparación con el resto.

We studied the distribution, mortality and association with plants, of 308 nests of the neotropical ant Paraponera clavata, in a permanent 50 hectare plot in old-growth forest on Barro Colorado island between September 1993 and February 1995. Ant nests were uniformly dispersed throughout the plot, and significantly associated with the high plateau and patch of young forest in the plot. The average density was 6.2 nests per hectare. Mortality of nests was higher with increasing number of neighbors within 20 m, compared to those separated at greater distances. The mortality was between 13.36% and 69.64% depending on the census interval, and recruitment between 22.63% and 31.72%. The nests were found in 84 plant species of 34 families, pertaining to four life forms: 76 species were trees, 5 were shrubs, 2 were palms and one was a liana. We tested for association between ant nests and tree species and tree size by examining whether nests were more common in certain categories than would be expected by change. Eight species of plants were positively associated with Paraponera clavata. The ant preferentially selected trees between 8 and 63.9 cm diameter at breast height. Trees and small shrubs were not associated with the nests. No association was found between ant nests and trees with extra-floral nectaries. Fifty-three percent of the nests had a Phrynus gervaisii (Amblypygi: Phrynidae) cohabiting inside. These nests had lower mortality rates than the rest.