Living fruits of Psychotria brachyceras Müll. Arg. (Rubiaceae) as the main larval host of Zygothrica orbitalis (Sturtevant, 1916) (Diptera, Drosophilidae)

ABSTRACT Zygothrica is a genus of Drosophilidae (Diptera) whose species utilize flowers and fungi for breeding sites, with records of fungi being used as courtship arena. Due to this habit, its representation in Drosophilidae surveys using banana-baited traps is generally low. However, Zygothrica orbitalis was well represented in a few samples with these traps. In this study, we report for the first time the breeding site of Z. orbitalis in living fruits of Psychotria brachyceras (Rubiaceae), noting that the use of living fruits is rare among Drosophilidae. The fructification of the plant occurs in the area of study from May to August, with previous collection records of the species in the Restinga (sandbank or strand) forest. Additionally, the emergence of some individuals of the invasive species Drosophila suzukii was observed, which highlights the necessity for continuous study of this plant to understand the dynamics between a native and an exotic species. Besides the ecological importance, our results are relevant for understanding the evolution of trophic resource use by the Zygothrica genus.

Trophic ecology of Acestrorhynchus falcirostris Cuvier, 1819 in island lakes on the lower stretch of the Solimões River, Amazon Basin / Ecologia trófica de Acestrorhynchus falcirostris Cuvier, 1819 em lagos de ilha no trecho inferior do Rio Solimões, Bacia Amazônica

Abstract The aim objective of this study was to determine the trophic ecology of juvenile and adult Acestrorhynchus falcirostris during the rising and flood (high-water) period in six island lakes adjacent to the Solimões River. As such, we investigated: i) the trophic position, through the fractional trophic niche; ii) the niche breadth; iii) niche overlap and iv) the food strategy of the species. The specimens were collected during the years 2014 to 2017, using gillnets with mesh sizes ranging from 30 to 120mm between opposite knots. Through the analysis of stomach contents, the preference in the consumption of items of animal origin was observed. Juveniles consumed insects in greater proportions (IAi% = 50%), while adults consumed fish (IAi%=99,98%). Despite the large supply of food items available in the high-water period, juveniles were the only ones to consume items of allochthonous origin, such as insects. Juveniles presented a different dietary strategy and dietary composition to adults. Juveniles were omnivores with a generalist strategy, while adults were piscivores with a specialist strategy. Thus, the food composition, niche breadth, trophic position and feeding strategy of Acestrorhynchus falcirostris change due to the stage of development.

Resumo O objetivo deste estudo foi determinar a ecologia trófica de juvenis e adultos de Acestrorhynchus falcirostris durante o período de enchente e cheia em seis lagos de ilha adjacentes ao rio Solimões. Assim, investigamos: i) a posição trófica, através do nicho trófico fracional; ii) a largura de nicho; iii) sobreposição de nicho; iv) a estratégia alimentar. Os espécimes foram coletados durante os anos de 2014 a 2017, utilizando redes de emalhar com malha variando de 30 a 120mm entre nós opostos. Por meio da análise do conteúdo estomacal, observamos a preferência no consumo de itens de origem animal. Os juvenis consumiram insetos em maiores proporções (IAi% = 50%), enquanto os adultos consumiram preferencialmente peixes (IAi% = 99,98%). Apesar da grande oferta de alimentos disponíveis no período da cheia, os juvenis eram os únicos a consumir itens de origem alóctone, como por exemplo, os insetos. Os juvenis apresentaram uma estratégia alimentar e composição alimentar diferente para os adultos. Os juvenis foram considerados onívoros com uma estratégia generalista, enquanto os adultos foram considerados piscívoros com uma estratégia alimentar mais especialista. Assim, a composição alimentar, amplitude do nicho, posição trófica e a estratégia alimentar de Acestrorhynchus falcirostris muda em função do estágio de desenvolvimento.

Trophic ecology of Acestrorhynchus falcirostris Cuvier, 1819 in island lakes on the lower stretch of the Solimões River, Amazon Basin

Abstract The aim objective of this study was to determine the trophic ecology of juvenile and adult Acestrorhynchus falcirostris during the rising and flood (high-water) period in six island lakes adjacent to the Solimões River. As such, we investigated: i) the trophic position, through the fractional trophic niche; ii) the niche breadth; iii) niche overlap and iv) the food strategy of the species. The specimens were collected during the years 2014 to 2017, using gillnets with mesh sizes ranging from 30 to 120mm between opposite knots. Through the analysis of stomach contents, the preference in the consumption of items of animal origin was observed. Juveniles consumed insects in greater proportions (IAi% = 50%), while adults consumed fish (IAi%=99,98%). Despite the large supply of food items available in the high-water period, juveniles were the only ones to consume items of allochthonous origin, such as insects. Juveniles presented a different dietary strategy and dietary composition to adults. Juveniles were omnivores with a generalist strategy, while adults were piscivores with a specialist strategy. Thus, the food composition, niche breadth, trophic position and feeding strategy of Acestrorhynchus falcirostris change due to the stage of development.

Resumo O objetivo deste estudo foi determinar a ecologia trófica de juvenis e adultos de Acestrorhynchus falcirostris durante o período de enchente e cheia em seis lagos de ilha adjacentes ao rio Solimões. Assim, investigamos: i) a posição trófica, através do nicho trófico fracional; ii) a largura de nicho; iii) sobreposição de nicho; iv) a estratégia alimentar. Os espécimes foram coletados durante os anos de 2014 a 2017, utilizando redes de emalhar com malha variando de 30 a 120mm entre nós opostos. Por meio da análise do conteúdo estomacal, observamos a preferência no consumo de itens de origem animal. Os juvenis consumiram insetos em maiores proporções (IAi% = 50%), enquanto os adultos consumiram preferencialmente peixes (IAi% = 99,98%). Apesar da grande oferta de alimentos disponíveis no período da cheia, os juvenis eram os únicos a consumir itens de origem alóctone, como por exemplo, os insetos. Os juvenis apresentaram uma estratégia alimentar e composição alimentar diferente para os adultos. Os juvenis foram considerados onívoros com uma estratégia generalista, enquanto os adultos foram considerados piscívoros com uma estratégia alimentar mais especialista. Assim, a composição alimentar, amplitude do nicho, posição trófica e a estratégia alimentar de Acestrorhynchus falcirostris muda em função do estágio de desenvolvimento.

Trophic morphology and diet of the endangered fish Tlaloc hildebrandi (Cyprinodontiformes: Profundulidae) / Morfología trófica y dieta de Tlaloc hildebrandi (Cyprinodontiformes: Profundulidae), especie amenazada de extinción

Abstract Introduction: Tlaloc hildebrandi is a freshwater killifish, endemic to Southern Mexico and under threat of extinction; the knowledge of the trophic morphology and diet is needed by conservation managers. Objective: To analyse and describe the anatomy of the visceral skeleton, visceral musculature, digestive tract and its adjoining glands of T. hildebrandi; as well as its diet. Methods: We performed the trophic anatomy on 20 adult specimens of both sexes, through manual dissection; as well as gut content analysis in 60 individuals to describe the diet. Results: As notable characters of the visceral skeleton of T. hildebrandi we found the posterior notch of the premaxillary, the presence of the "coronoid cartilage", the tricuspid shape of the gill rakers of the first branchial arch, and the presence of the coronomeckelian bone; some outstanding characters of the visceral musculature are the origin of the retractor dorsalis muscle from the first four vertebral centra, and the division of the pharyngoclavicularis externus muscle into two sections. The notable characters of the digestive tube are the absence of stomach and pyloric caeca, and the presence of the "intestinal valve". Insects (IVI = 66.6 %) and ostracods (13 % IVI) were the dominant prey items of the Tlaloc hildebrandi diet; larvae and adults of the family Chironomidae were the most dominant insects in the diet (53 % IVI). Conclusions: The organization of the digestive system of T. hildebrandi corresponds to the general morphologic pattern of the Cyprinodontiformes; however, we register as new information for these fish, the presence of the "coronoid cartilage" and the "intestinal valve". The structures of the trophic morphology and the components of the diet, confirms us that T. hildebrandi is a carnivorous-insectivorous fish.

Resumen Introducción: Tlaloc hildebrandi es un killi de agua dulce, endémico del sur de México y bajo amenaza de extinción; el conocimiento de la morfología trófica y la dieta son necesarios para los administradores de la conservación. Objetivo: Analizar y describir la anatomía del esqueleto visceral, la musculatura visceral, el tracto digestivo y las glándulas adyacentes de T. hildebrandi; así como los componentes de su dieta. Métodos: Mediante la técnica del descarnado manual, realizamos la descripción de la anatomía trófica en 20 especímenes adultos de ambos sexos, y el análisis del contenido estomacal en 60 individuos para describir la dieta. Resultados: Como caracteres sobresalientes del esqueleto visceral de T. hildebrandi está la escotadura posterior del premaxilar, la presencia del "cartílago coronoides", la forma tricúspide de las branquiespinas del primer arco branquial y la presencia del hueso coronomeckeliano; como caracteres de la musculatura visceral sobresalen el origen del músculo retractor dorsalis de los cuatro primeros centros vertebrales, y la división del músculo pharyngoclavicularis externus en dos secciones. Los caracteres notables del tubo digestivo son la ausencia de estómago y de ciegos pilóricos y la presencia de la "válvula intestinal". Los insectos (IVI = 66.6 %) y ostrácodos (13 % IVI) fueron los componentes dominantes de la dieta de T. hildebrandi; particularmente las larvas y adultos de la familia Chironomidae fueron los insectos más abundantes en la dieta (53 % IVI). Conclusiones: La organización del sistema digestivo de T. hildebrandi corresponde al patrón morfológico general de los Cyprinodontiformes, sin embargo, se registra como nueva información para estos peces, la presencia del cartílago coronoides y la válvula intestinal. Las estructuras de la morfología trófica y los componentes de la dieta nos confirman que T. hildebrandi es un pez carnívoro-insectívoro.

Capacidad del diámetro biparietal para predecir los recién nacidos grandes para edad gestacional. Estudio de cohorte retrospectivo / Ability of biparietal diameter to predict large for gestational age newborns. A retrospective cohort study

Fundamento: Predecir el recién nacido grande para la edad gestacional es una acción de salud que necesita de herramientas tecnológicas de probada eficiencia. Objetivo: Determinar la capacidad predictiva del diámetro biparietal en los recién nacidos grandes para la edad gestacional. Metodología: Estudio de cohorte retrospectivo que incluyó 1959 gestantes cubanas con embarazo simple con captación y término del embarazo entre enero del 2009 y diciembre de 2017. En cada trimestre de gestación se compararon las condiciones tróficas adecuado para la edad gestacional (AEG) y grandes para la edad gestacional (GEG) mediante estadígrafos de tendencia central (media) y de dispersión (rango, desviación estándar) correspondientes al diámetro biparietal. Se calculó además el intervalo de confianza (IC) de 95 % para la diferencia de medias del diámetro biparietal. Asimismo, se realizó un análisis de curvas ROC para determinar si el diámetro biparietal y el peso fetal predicen la condición trófica grande para la edad gestacional en el segundo y tercer trimestre de gestación. Los datos fueron recogidos del libro registro de genética del área de salud. Resultados: El diámetro biparietal en el segundo y tercer trimestre de gestación tuvo un área bajo curva de 0.60 (IC 95 %: 0.54-0.65) y 0.59 (IC 95 %: 0.54-0.64) respectivamente. Los puntos de corte establecidos (T2: 56.55 mm, T3: 81.55 mm) tienen una especificidad y exactitud superior al 78 %. Conclusiones: El diámetro biparietal y los modelos de regresión de Shepard y de Hadlock V mostraron capacidad para discriminar el nacimiento grande para la edad gestacional del adecuado para la edad gestacional, a partir del segundo trimestre de gestación siendo más eficaces en el tercero.

Background: Predicting large for gestational age newborns is a medical action that requires technological tools with proven efficiency. Objective: To determine the predictive ability of biparietal diameter in large newborns for gestational age. Methodology: Retrospective cohort study that included 1959 Cuban pregnant women with a singleton pregnancy, with recruitment and pregnancy term between January 2009 and December 2017. In each gestational trimester, trophic conditions appropriate for gestational age (GAW) were compared and large for gestational age (GA) using central tendency (mean) and dispersion (range, standard deviation) statistics corresponding to the biparietal diameter. The 95% confidence interval (CI) for mean biparietal diameter difference was also calculated. In addition, an analysis of ROC curves was performed to determine if biparietal diameter and fetal weight predict large trophic condition for gestational age in the second and third gestational trimester. Data were gathered from the health area genetics registry book. Results: Biparietal diameter in the second and third trimester of gestation had an area under curve of 0.60 (95% CI: 0.54-0.65) and 0.59 (95% CI: 0.54-0.64) respectively. The established cut-off points (T2: 56.55 mm, T3: 81.55 mm) have a specificity and accuracy greater than 78%. Conclusions: Biparietal diameter and the Shepard and Hadlock V regression models showed ability to discriminate large for gestational age birth from adequate for gestational age birth from the second trimester of gestation onward, being more effective in the third trimester.

Relación entre biometría fetal, producto de acumulación de los lípidos y condición trófica al nacer / Relationship between fetal biometry, lipid accumulation product and the trophic condition at birth

Fundamento: Las alteraciones del estado nutricional materno generalmente se relacionan con desviaciones del crecimiento fetal, que pueden detectarse por los parámetros biofísicos fetales e identifican la posible condición trófica al nacer. Objetivo: Determinar la posible relación entre los parámetros biométricos fetales, la condición trófica al nacer y el producto de acumulación de los lípidos. Metodología: Se realizó un estudio transversal en el Policlínico Chiqui Gómez Lubian del municipio Santa Clara, durante el año 2019, en una población de 253 gestantes normopeso supuestamente sanas al inicio de la gestación. La muestra no probabilística fue de 144 gestantes. Las variables de estudio fueron: producto de acumulación de los lípidos, biometría fetal y condición trófica al nacer. Se utilizaron métodos teóricos, empíricos y estadísticos. Resultados: En el segundo trimestre ningún parámetro biométrico coincidió con la condición al nacer de pequeño, mientras que para el grande coincidieron las circunferencias cefálica y abdominal. En el tercer trimestre la longitud del fémur y la circunferencia abdominal coinciden en la identificación del pequeño y del grande. El PAL se correlacionó con la circunferencia abdominal del tercer trimestre y con el peso al nacer; presentando mayor frecuencia de valores en el tercer tertil para los nacimientos grandes. Conclusiones: La circunferencia abdominal fue el parámetro biométrico con mayor coincidencia con la condición trófica al nacer, la que se asoció con valores en el tercer tertil del PAL para la detección de nacimientos grandes, relacionándose el fenotipo normopeso metabólicamente obeso con el crecimiento fetal por exceso.

Background: Maternal nutritional status disorders are usually related to fetal growth deviations, which can be detected by fetal biophysical parameters and identify the possible trophic condition at birth. Objective: To determine the possible relationship between fetal biometric parameters, the birth trophic state and lipid accumulation product. Methodology: A cross-sectional study was conducted at the Chiqui Gómez Lubian Polyclinic in Santa Clara municipality, during 2019, in a population of 253 normal-weight pregnant women who were apparently healthy at the beginning of their gestation. The non-probability sample was made up of 144 pregnant women. Study variables were: lipid accumulation product, fetal biometry and trophic condition at birth. Theoretical, empirical and statistical methods were used. Results: In the second trimester, none of the biometric parameters matched the condition at birth as a small child, while in the large one the head and abdominal circumferences matched. In the third trimester, femoral length and abdominal circumference coincide in identifying the small one and the large one. LAP correlated with third trimester abdominal circumference and birth weight, presenting higher frequency of values in the third tertile for large births. Conclusions: Abdominal circumference was the biometric parameter with the highest coincidence with trophic condition at birth, associated with values in the third tertile of the LAP for detecting large births, relating the metabolically obese normal weight phenotype with excessive fetal growth.

Diet of Moenkhausia bonita (Benine, Castro & Sabino 2004) (Characiformes: Characidae) in streams in the basin of rio Formoso, Brazilian Midwest

To characterize the diet composition of Moenkhausia bonita and its temporal and ontogenetic variations in streams in the Formoso River basin (MS). The collections were carried out in seven sampling points in two periods throughout the year (dry and rainy). The food items were analyzed according to the volumetric and occurrence frequency methods and the diet was characterized through the Food Index (IAi%). To determine ontogeny, the specimens were divided into five size classes in the dry (D1 to D5) and rainy (R1 to R5) periods. To verify the difference between the species' diet between the size classes and the periods of the year, the Permutational Multivariate Analysis of Variance ­ PERMANOVA analysis was performed. Moenkhausia bonita was classified as an invertivore when it consumed basically both aquatic and terrestrial invertebrates (99.5% of the diet), with higher consumption of aquatic invertebrates. There was a significant difference in the diet of between the dry and rainy periods, and although the species basically consumed the same items in the two studied periods, the proportions were different and there was no difference in the diet between size classes. M. bonita diet is based on autochthonous resources regardless of the size class, but that there were different consumption patterns when comparing the different periods of the year. The present study provided the first information on the feeding of M. bonita in a lotic environment and diet spectrum in the developmental phases, (ontogeny) and periods of the year, enabling a better understanding of the species, the importance of invertebrates in its diet, and the need for future studies on the biology, autoecology, and behavior of this species.

Minimalist revision of Mesochorus Gravenhorst, 1829 (Hymenoptera: Ichneumonidae: Mesochorinae) from Área de Conservación Guanacaste, Costa Rica, with 158 new species and host records for 129 species / Revisión minimalista de Mesochorus Gravenhorst, 1829 (Hymenoptera: Ichneumonidae: Mesochorinae) del Área de Conservación Guanacaste, Costa Rica, con 158 especies nuevas y registros de hospedantes para 129 especies

Introduction: Species of Mesochorus are found worldwide and members of this genus are primarily hyperparasitoids of Ichneumonoidea and Tachinidae. Objectives: To describe species of Costa Rican Mesochorus reared from caterpillars and to a lesser extent Malaise-trapped. Methods: The species are diagnosed by COI mtDNA barcodes, morphological inspection, and host data. A suite of images and host data (plant, caterpillar, and primary parasitoid) are provided for each species. Results: A total of 158 new species of Mesochorus. Sharkey is the taxonomic authority for all. Conclusions: This demonstrates a practical application of DNA barcoding that can be applied to the masses of undescribed neotropical insect species in hyperdiverse groups.

Introducción: Las especies de Mesochorus se encuentran en todo el mundo y los miembros de este género son principalmente hiperparasitoides de las familias Ichneumonoidea y Tachinidae. Objetivos: Describir las especies de Mesochorus costarricenses obtenidas de orugas y en menor medida por trampas Malaise. Métodos: Las especies se diagnosticaron mediante el uso de código de barra molecular por COI del ADNmt, inspección morfológica y datos del huésped. Se proporciona un conjunto de imágenes y datos de los huéspedes (planta, oruga y parasitoide primario) para cada especie. Resultados: Se encontró un total de 158 nuevas especies de Mesochorus. Sharkey es la autoridad taxonómica para todas las especies. Conclusiones: Se demuestra una aplicación práctica del código de barras de ADN que se puede aplicar a grandes cantidades de especies de insectos neotropicales no descritas para grupos hiperdiversos.

Diet of Moenkhausia bonita (Benine, Castro & Sabino 2004) (Characiformes: Characidae) in streams in the basin of rio Formoso, Brazilian Midwest

To characterize the diet composition of Moenkhausia bonita and its temporal and ontogenetic variations in streams in the Formoso River basin (MS). The collections were carried out in seven sampling points in two periods throughout the year (dry and rainy). The food items were analyzed according to the volumetric and occurrence frequency methods and the diet was characterized through the Food Index (IAi%). To determine ontogeny, the specimens were divided into five size classes in the dry (D1 to D5) and rainy (R1 to R5) periods. To verify the difference between the species' diet between the size classes and the periods of the year, the Permutational Multivariate Analysis of Variance ­ PERMANOVA analysis was performed. Moenkhausia bonita was classified as an invertivore when it consumed basically both aquatic and terrestrial invertebrates (99.5% of the diet), with higher consumption of aquatic invertebrates. There was a significant difference in the diet of between the dry and rainy periods, and although the species basically consumed the same items in the two studied periods, the proportions were different and there was no difference in the diet between size classes. M. bonita diet is based on autochthonous resources regardless of the size class, but that there were different consumption patterns when comparing the different periods of the year. The present study provided the first information on the feeding of M. bonita in a lotic environment and diet spectrum in the developmental phases, (ontogeny) and periods of the year, enabling a better understanding of the species, the importance of invertebrates in its diet, and the need for future studies on the biology, autoecology, and behavior of this species.

: Caracterizar a composição alimentar de Moenkhausia bonita e as variações temporais e ontogenéticas na dieta desta espécie em riachos da bacia do rio Formoso (MS). As coletas foram realizadas em sete pontos amostrais em dois períodos do ano (seco e chuvoso). Os itens alimentares foram analisados de acordo com os métodos volumétrico e de frequência de ocorrência e a dieta foi caracterizada através do Índice Alimentar (IAi%). Para determinar a ontogenia, os espécimes foram divididos em cinco classes de tamanho nos períodos seco (D1 a D5) e chuvoso (R1 a R5). Para verificar a diferença entre a dieta da espécie entre as classes de tamanho e os períodos do ano foi realizado a Análise de Variância Multivariada Permutacional ­ PERMANOVA. M. bonita foi classificada como invertívora ao consumir basicamente invertebrados tanto aquáticos quanto terrestres (99,5% da dieta), com consumo maior de invertebrados aquáticos. Houve diferença significativa na dieta entre os períodos seco e chuvoso, apesar da espécie consumir basicamente os mesmos itens nos dois períodos estudados, as proporções foram distintas e não houve diferença na dieta entre as classes de tamanho. A dieta de M. bonita é baseada em recursos autóctones independente da classe de tamanho, mas que houve consumo diferente entre os períodos do ano. O presente estudo forneceu as primeiras informações sobre a alimentação de M. bonita em ambiente lótico e seu espectro alimentar nas fases de desenvolvimento(ontogenia)e períodos do ano, possibilitando melhor conhecimento da espécie, a importância dos invertebrados em sua dieta e a necessidade de estudos futuros sobre a biologia, autoecologia e comportamento desta espécie.

Infection of perennial ryegrass (Lolium perenne) by an endophyte fungus (Neotyphodium lolii) decreases the abundance and diversity of predators and parasitoids

ABSTRACT Perennial ryegrass is one of the most important food sources in animal production. However, several pests affect this crop, and one of the primary control strategies is the symbiotic relationships between ryegrass endophyte fungi. This fungus produces alkaloids that exhibit toxic activity against arthropods. Furthermore, the effect of fungi may extend to higher trophic levels, including predators (spiders and/or insects), decreasing their abundance and diversity. Given the importance of spiders and insects as predators, whether the symbiotic interaction between perennial ryegrass and endophyte fungus reduces the abundance and diversity of predators pose an important question. To address this question, natural enemies in perennial ryegrass were collected and analyzed over a year, and the percentage of endophyte fungus was evaluated by the presence of hyphae from two ryegrass cultivars, Jumbo (E-) and Alto AR1 (E+). We observed an 80% endophyte infection rate for (E+) and 0% for (E-). Moreover, 222 individual spiders corresponding to 10 families were identified in both perennial ryegrasses, including 209 individuals for (E-) and 13 for (E+). The most abundant spider family was Lycosidae, representing 71.17% of the total spiders. In addition, 65 insects were collected, corresponding to 6 families, with Carabidae being the most abundant. Furthermore, the Simpson index indicated the dominance of the family Lycosidae. Overall, spider and insect abundance and diversity were reduced in (E+), suggesting a negative effect of the endophyte on predator populations.

Altitudinal distribution of the functional feeding groups of aquatic macroinvertebrates using an ecological network in Andean streams / Distribución altitudinal de los grupos funcionales de alimentación de macroinvertebrados acuáticos utilizando una red ecológica en arroyos andinos

Abstract Introduction: Analysis of functional feeding groups (FFG) in aquatic macroinvertebrates is important in understanding the structure, function, and dynamics of ecological processes in ecosystems. Modularity refers to the degree of compartmentalization of food webs and varies between -1 and 1. A network with a modularity value close to 1 is resilient to disturbances and can be interpreted as an indicating factor for the stability of communities. Objective: In this study, we analyzed the trophic structure of benthic macroinvertebrates in La Nitrera stream, the San Juan River, and the Cauca River in the Colombian Andes. Methods: The study was supported by ecological networking techniques using Gephi software. We studied nine sites in dry, rainy, and transition seasons in 2017 and 2018, monitoring changes in the altitude gradient. At each of the sites, the organisms were captured and determined, and physicochemical and hydraulic information was obtained. Results: The variance component analysis allowed to explain the variability of the data by relating the following environmental variables: FFG, diversity, richness, modularity, season, and time. Simple multifactorial ANOVA indicated that significant changes in FFG were associated with altitude, and modularity to time. The allocation of the FFG was done by stomach analysis and secondary information. Conclusion: The transition season had the highest modularity, possibly due to the recolonization of some biotopes caused by the decrease in the velocity of water currents. La Nitrera and San Juan presented higher values than the Cauca, which may indicate that the altitudinal change and velocity of water currents affects the compartmentalization of the network.

Resumen Introducción: El análisis de grupos funcionales de alimentación (GFA) en macroinvertebrados acuáticos es importante para comprender la estructura, función y dinámica de los ecosistemas de procesos ecológicos. La modularidad se refiere al grado de compartimentación de las redes alimentarias y varía entre -1 y 1. Una red con un valor de modularidad cercano a 1 es resistente a las alteraciones y puede interpretarse como un factor indicativo para la estabilidad de las comunidades. Objetivo: En este estudio se analizó la estructura trófica de los macroinvertebrados bentónicos, un elemento importante en la calidad ambiental, en el arroyo La Nitrera, el río San Juan y el río Cauca. Métodos: El estudio contó con el apoyo de técnicas de redes ecológicas utilizando el software Gephi. En 2017 y 2018, estudiamos nueve sitios en estaciones secas, lluviosas y de transición, monitoreando cambios en el gradiente de altitud. En cada uno de los sitios se capturaron y determinaron los organismos y se recogió información fisicoquímica e hidráulica. Resultados: El análisis de componentes de varianza permitió explicar la variabilidad de los datos relacionando las siguientes variables ambientales: GFA, diversidad, riqueza, modularidad, estación y tiempo. La ANOVA simple multifactorial indicó que existen cambios significativos en los GFA en relación con la altitud, y la modularidad con el tiempo. La asignación de los GFA se realizó mediante análisis estomacal e información secundaria. Conclusión: La temporada de transición tuvo la mayor modularidad, posiblemente debido a la recolonización de algunos biotopos provocada por la disminución de la velocidad del cauce. La Nitrera y San Juan presentaron valores superiores a los del Cauca, lo que puede indicar que el cambio altitudinal y la velocidad de las corrientes de agua influyen en la compartimentación de la red.

A new interaction in an invasive plant in Brazil: Horismenus abnormicaulis (Hymenoptera, Eulophidae) parasitizing Acanthoscelides macrophthalmus (Coleoptera, Chrysomelidae, Bruchinae) in seeds pods of Leucaena leucocephala (Fabaceae)

ABSTRACT The parasitism of Acanthoscelides macrophthalmus (Coleoptera, Chrysomelidae, Bruchinae) by the parasitoid Horismenus abnormicaulis (Hymenoptera: Eulophidae) is described for the first time. We harvested 90 Leucaena leucocephala (Fabaceae, Mimosoideae) fruit pods, in June 2019 on the campus of the Federal University of Lavras in the municipality of Lavras, Minas Gerais, Brazil. We found 21 individuals of H. abnormicaulis and 334 of A. macrophthalmus. The presence of cephalic capsule of beetle's pupa and evidence of predation into seed pods from which the wasps emerged suggested H. abnormicaulis is a parasitoid of A. macrophthalmus. Horismenus abnormicaulis has been added to the list of A. macrophthalmus parasitoids, and its occurrence has been expanded to the state of Minas Gerais. This discovery expands our knowledge of H. abnormicaulis biology and distribution in Brazil, as well as the tri-trophic interaction, plant-herbivore-parasitoid in invasive plant systems.

Linking toxicity and predation in a venomous arthropod: the case of Tityus fuhrmanni (Scorpiones: Buthidae), a generalist predator scorpion

Background: Scorpions are arachnids that have a generalist diet, which use venom to subdue their prey. The study of their trophic ecology and capture behavior is still limited compared to other organisms, and aspects such as trophic specialization in this group have been little explored. Methods: In order to determine the relationship between feeding behavior and venom toxicity in the scorpion species Tityus fuhrmanni, 33 specimens were offered prey with different morphologies and defense mechanisms: spiders, cockroaches and crickets. In each of the experiments we recorded the following aspects: acceptance rate, immobilization time and the number of capture attempts. The median lethal dose of T. fuhrmanni venom against the three different types of prey was also evaluated. Results: We found that this species does not have a marked difference in acceptance for any of the evaluated prey, but the number of capture attempts of spiders is higher when compared to the other types of prey. The immobilization time is shorter in spiders compared to other prey and the LD50 was higher for cockroaches. Conclusions: These results indicate that T. fuhrmanni is a scorpion with a generalist diet, has a venom with a different potency among prey and is capable of discriminating between prey types and employing distinct strategies to subdue them.(AU)

Linking toxicity and predation in a venomous arthropod: the case of Tityus fuhrmanni (Scorpiones: Buthidae), a generalist predator scorpion

Abstract Background: Scorpions are arachnids that have a generalist diet, which use venom to subdue their prey. The study of their trophic ecology and capture behavior is still limited compared to other organisms, and aspects such as trophic specialization in this group have been little explored. Methods: In order to determine the relationship between feeding behavior and venom toxicity in the scorpion species Tityus fuhrmanni, 33 specimens were offered prey with different morphologies and defense mechanisms: spiders, cockroaches and crickets. In each of the experiments we recorded the following aspects: acceptance rate, immobilization time and the number of capture attempts. The median lethal dose of T. fuhrmanni venom against the three different types of prey was also evaluated. Results: We found that this species does not have a marked difference in acceptance for any of the evaluated prey, but the number of capture attempts of spiders is higher when compared to the other types of prey. The immobilization time is shorter in spiders compared to other prey and the LD50 was higher for cockroaches. Conclusions: These results indicate that T. fuhrmanni is a scorpion with a generalist diet, has a venom with a different potency among prey and is capable of discriminating between prey types and employing distinct strategies to subdue them.

Simulación de la dinámica de la biomasa en plancton de un embalse colombiano tropical andino de alta montaña / Simulation of biomass dynamics in plankton of a high-altitude andean tropical reservoir in colombia

ABSTRACT The understanding of the relationships between the planktonic communities in a reservoir allows us to infer possible changes in the redistribution of matter and energy flows in these systems. This work proposes a dynamic model for the trophic network of the Riogrande II tropical reservoir, which integrates the planktonic trophic chains of detritus and grazing, limiting the prey-predator interactions by introducing the prey meeting factor (pmf). We built a dynamic model of mass balance supported by an extensive bibliographic search. The limitations of consumers and resources were represented simultaneously by means of the pmf. The data used to validate the model were compiled from previous investigations carried out in this reservoir from 2010 to 2013. The values of pmf that we found in each simulation suggest that the top predator can access its main prey in certain concentrations of total phosphorus, with a probability of encounter ranging from 9.3 % to 17.7 %. Our simulations indicate that most of the primary production is poorly used by the primary consumers in the photic zone, however, it enters in the flows of the detrital chain and supports the production of zooplankton almost entirely. According to this finding, the biomass densities obtained in the previous studies can be better explained by the causal relationships assumed in this model.

RESUMEN Entender las relaciones entre las comunidades planctónicas en un embalse nos permite inferir posibles cambios en la redistribución de los flujos de materia y energía en este sistema. Este trabajo propone un modelo dinámico para representar la red trófica del embalse tropical Riogrande II, donde se integran las cadenas tróficas de pastoreo y detritus y se limitan las interacciones entre predadores, presas y recursos al introducir un factor limitante de encuentro con la presa (pmf). El modelo dinámico se enfoca en el balance de masas sustentado en una amplia búsqueda bibliográfica. Los datos usados para validar el modelo se colectaron de datos previamente reportados para el embalse durante los años 2010 y 2013. Los valores de pmf obtenidos en cada simulación, sugieren que el predador dominante puede acceder a su presa principal a ciertas concentraciones de fósforo total, con una probabilidad de encuentro que va desde 9,3 % hasta 17,7 %. Nuestros resultados indican que la mayor parte de la producción primaria es poco aprovechada por los consumidores en la zona fótica, sin embargo, ingresa en el flujo de la cadena detrítica de manera que soporta la producción de zooplancton casi por completo. Las relaciones causales asumidas en este modelo explican en gran medida las densidades de biomasa reportadas en estudios previos.

Vertical stratification of arthropods in the dry ecosystems of Colombian Guyana: morphological patterns and their ecological implications / Estratificación vertical de artrópodos en ecosistemas secos de la Guayana colombiana: patrones morfológicos y sus implicaciones ecológicas

Abstract Introduction: Despite growing interest by the ecosystems derived from the Guyanese formations, the vertical structure of the communities and relationships of the biota with the climatic conditions in these ecosystems are unknown. Objective: Characterize the structure and vertical composition of the arthropod fauna associated with three of the most representative ecosystems of the Northern area of the serranía de La Lindosa in Colombia based on morphological and ecological parameters. Methods: The arthropod fauna was sampled, from the subsurface soil level to the shrub and tree stratum. The fauna was determined up to the level of family or supraspecific group and the values of Alfa and Beta diversity were determined. Body length measurements were made, and the coloration and trophic level of each group were determined. Results: The composition and diversity of the arthropod fauna was different in each ecosystem and vertical stratum and most of the groups in all the ecosystems studied present low abundances. Groups of phytophagous and predatory habits were frequent in all ecosystems and the highest biomass of arthropod fauna comes from groups of polyphagous habits, of medium size and great abundance. Light and dark colorations are the most frequent in landscape-scale. Conclusion: The ecosystems studied are characterized by the low values of diversity and replacement and the large number of non-shared groups that apparently respond to the microclimatic characteristics; however, there are some generalities on a landsc ape scale such as the greater richness and abundance of groups in the intermediate strata, the greater proportion of groups with phytophagous habits and medium body sizes, and the predominance of dark colorations in the lower strata.

Resumen Introducción: A pesar del interés que despiertan los ecosistemas derivados de las formaciones guyanesas, se desconoce la estructura vertical de las comunidades y las relaciones de la biota con las condiciones climáticas. Objetivo: Caracterizar la estructura y composición vertical de la artropofauna asociada a tres de los ecosistemas más representativos de la zona norte de la serranía de La Lindosa en Colombia, con base en parámetros morfológicos y ecológicos. Métodos: Se muestreó la artropofauna, desde el nivel del suelo subsuperficial hasta los estratos arbustivos y arbóreos, y se identificó hasta el nivel de familia o grupo supraespecífico. Se determinaron los valores de diversidad Alfa y Beta, se realizaron mediciones de la longitud corporal y se determinó la coloración y el nivel trófico de cada grupo. Resultados: La composición y diversidad de la artropofauna fue diferente en cada ecosistema y estrato vertical y la mayoría de los grupos de artrópodos en todos los ecosistemas estudiados presentan abundancias bajas. Los grupos de hábitos fitófagos y depredadores fueron frecuentes en todos los ecosistemas y la mayor biomasa de artropofauna proviene de grupos de hábitos polífagos, de tamaño medio y de gran abundancia. Las coloraciones claras y oscuras son las más frecuentes a escala de paisaje. Conclusión: Los ecosistemas estudiados se caracterizan por los bajos valores de diversidad y recambio y por la gran cantidad de grupos no compartidos que aparentemente responden a las características microclimáticas; sin embargo, existen algunas generalidades a escala de paisaje como la mayor riqueza y abundancia de grupos en los estratos intermedios, la mayor proporción de grupos de hábitos fitófagos y tallas corporales medianas y el predominio de coloraciones oscuras en los estratos inferiores.

Zooplankton communities and their relationship with water quality in eight reservoirs from the midwestern and southeastern regions of Brazil / Comunidades de zooplâncton e sua relação com a qualidade da água em oito reservatórios das regiões Centro-Oeste e Sudeste do Brasil

Abstract Zooplankton are widely recognised as being regulated primarily by predators and food availability. In reservoirs, the quantity and quality of food resources are generally affected by the characteristics of the water, which in turn are controlled by the flow pulse generated by operation of the dams. In this study, we investigated the relationship between zooplankton, water quality and food availability (phytoplankton) in eight hydroelectric reservoirs located in Brazil. Samples were collected during the rainy and dry periods between 2008 and 2009. In general, the reservoirs exhibited mesotrophic conditions and Cyanobacteria were the predominant phytoplankton. The results showed that the rotifers Kellicottia bostoniensis, Hexarthra mira, Keratella spp., and Polyarthra vulgaris were present, indicating nutrient-rich environments. In addition, the copepod Thermocyclops decipiens occurred in eutrophic environments. In contrast, the cladoceran Daphnia gessneri and copepod Notodiaptomus henseni were considered indicators of more desirable water quality, owing to their relationship with waters with lower levels of nutrients and suspended solids. The results support the use of these organisms as a useful tool for understanding changes in water quality and in the ecosystem processes involved.

Resumo O zooplâncton é amplamente reconhecido como sendo regulado principalmente por predadores e pela disponibilidade de alimento. Em reservatórios, a quantidade e a qualidade de recursos alimentares são afetadas pelas características da água que, por sua vez, são controladas pelo pulso de fluxo gerado pela operação das barragens. Neste estudo, investigamos a relação entre o zooplâncton, qualidade d'água e a disponibilidade de alimento (fitoplâncton) em oito reservatórios hidrelétricos localizados no Brasil. Amostras foram coletadas durante os períodos chuvoso e seco, entre os anos de 2008 e 2009. Em geral, os reservatórios exibiram condições mesotróficas e Cyanobacteria foi o fitoplâncton predominante. Os resultados mostraram que os rotíferos Kellicottia bostoniensis, Hexarthra mira, Keratella spp. e Polyarthra vulgaris foram indicadores de ambientes ricos em nutrientes. Além disso, o copépode Thermocyclops decipiens ocorreu em ambientes eutróficos. Por outro lado, o cladócero Daphnia gessneri e o copépode Notodiaptomus henseni foram considerados indicadores de melhor qualidade da água, devido a sua relação com águas com baixos níveis de nutrientes e sólidos em suspensão. Os resultados suportam o uso desses organismos como uma ferramenta útil para o entendimento das mudanças na qualidade d'água e nos processos ecossistêmicos envolvidos.

Hábitos alimentarios de tres especies de peces lenguados (Pleuronectiformes: Achiridae) en la Bahía de Buenaventura, Pacífico Colombiano / Feeding habits of three species of sole fish (Pleuronectiformes: Achiridae) in Buenaventura Bay, Colombian Pacific

Resumen Introducción: La dinámica de las condiciones ambientales influencia la variación del alimento disponible para los organismos estuarinos, afectando el consumo de alimento de los organismos bentónicos como los lenguados, esenciales para establecer y monitorear la calidad ambiental en estos ecosistemas. Objetivo: Determinar los hábitos tróficos de tres especies de la familia Achiridae en la Bahía de Buenaventura, Pacífico colombiano. Métodos: Los peces se recolectaron por medio de pesca de arrastre artesanal. Así mismo, en laboratorio se determinó la dieta de cada una de las especies y se calcularon diferentes índices tróficos, registrando diferencias en los hábitos alimentarios entre estas especies. Resultados: Se recolectó un total de 159 peces del género Achirus, siendo la especie más abundante Achirus klunzingeri (98), luego Achirus mazatlanus (44) y finalmente Achirus scutum (17). La dieta de A. scutum se basó en detritos, la de A. mazatlanus en detritos y peces y la de A. klunzingeri en crustáceos y peces. Los individuos de A. klunzingeri presentaron diferencias en su dieta entre la zona interna y externa del estuario, en la zona interna los peces fueron la presa principal y en la zona externa fueron los crustáceos. Las especies A. klunzingeri y A. mazatlanus presentaron ingesta de microplásticos, principalmente fibras alargadas e incoloras presentes en individuos de todas las tallas. La dinámica de los hábitos tróficos de A. klunzingeri, se relacionaron con algunas variables ambientales, como temperatura, trasparencia y oxígeno disuelto. Por ejemplo, estas tres variables presentaron correlaciones negativas con el ítem peces, y positivas para la categoría crustáceos. Conclusión: Se evidenció que estas especies son generalistas y que las condiciones ambientales no solo influenciaron la dinámica del consumo alimentario, sino que también, determinaron la presencia de los microplásticos.

Abstract Introduction: The dynamic of the environmental conditions influences the availability of the food resources for the estuarine organisms, affecting the food consumption of the benthic organism such as the soles, which are essential for establishing and monitoring the environmental quality of these ecosystems. Objective: To determine the trophic habits of three species of the Achiridae family in Buenaventura Bay, Colombian Pacific. Methods: Fish were captured using artisanal trawling. Then, the diet of each species was determined and different trophic indexes were calculated registering differences in alimentary habits among species. Results: It was collected a total of 159 fishes of the genus Achirus, being the most abundant Achirus klunzingeri (98), then Achirus mazatlanus (44) and finally Achirus scutum (17). The diet of A. scutum was based on detritus, the diet of A. mazatlanus was mainly detritus and fish whereas the diet of A. klunzingeri presented a dynamic pattern based mainly on crustaceans and fish. The individuals of Achirus klunzingeri presented differences in the diet between the internal and external area of the estuary, in the internal zone the fish were the main prey while in the external zone were the crustaceans. The species A. klunzingeri and A. mazatlanus presented ingestion of microplastics, mainly elongated and colorless fibers which were present in individuals of all sizes. The dynamic of the trophic habits of A. klunzingeri was related to the environmental variables such as temperature, transparency and dissolved oxygen. For example, these three variables presented negative correlations with the item fishes, and positive for the crustacean category. Conclusions: Despite the generalist nature of the studied species, the environmental conditions, not only influenced the food consumption dynamic, but also determined the presence of microplastics.

Bat (Mammalia: Chiroptera) biodiversity in a subtropical inselberg ecosystem of Northeastern Argentina / Biodiversidad de murciélagos (Mammalia: Chiroptera) en un ecosistema inselberg subtropical del Noreste de Argentina

Abstract Introduction: Rocky outcrops influence both micro and macro habitat for plants and animals by increasing the availability and predictability of food, providing shelter, and unique microclimatic conditions. Objective: We describe the bat assemblage in three isolated rocky outcrops and their surrounding pediments, adding new data about trophic guilds and roosts. Methods: We surveyed the bat fauna of Paraje Tres Cerros, Corrientes Province, Argentina, exploring 13 sites during 26 field trips, using mist nets and search of roosts. We made an accumulation species curve and calculate inventory completeness. The similarity and composition of different habitats was compared by a Non-Metric Multidimensional Scaling (NMDS) and an ANOSIM test. Results: We reported 13 species, with a completeness inventory of the 80 % (Jacknife1), corresponding to the families Vespertilionidae, Molossidae and Phyllostomidae. The insectivorous bats were the best represented guild. We found nine types of roost for eight species in different sites. The analysis expressed low differences in the species composition between both types of habitats in the area. Conclusions: The rocky outcrops and their pediments are important ecosystems for the conservation and diversity of the bats in the region, since their assemblages are regionally unique.

Resumen Introducción: Los afloramientos rocosos influyen tanto en el micro como en el macro hábitat de plantas y animales al incrementar la disponibilidad de alimentos, proporcionar refugios y brindar condiciones microclimáticas únicas. Objetivo: Describir el ensamble de murciélagos en tres afloramientos rocosos aislados y sus pendientes circundantes, incorporando nuevos datos sobre gremios tróficos y refugios. Métodos: Muestreamos la fauna de murciélagos del Paraje Tres Cerros, provincia de Corrientes, Argentina, exploramos 13 sitios durante 26 viajes de campo, usando redes de niebla y búsqueda de refugios. Realizamos una curva de acumulación de especies y calculamos la completitud del inventario. La similitud y composición de diferentes hábitats se comparó mediante un escalado multidimensional no métrico (NMDS) y una prueba ANOSIM. Resultados: Reportamos 13 especies, con una completitud del 80 % del inventario (Jacknife1), correspondientes a las familias Vespertilionidae, Molossidae y Phyllostomidae. Los gremios mejor representados fueron los insectívoros. Encontramos nueve tipos de refugios para ocho especies en diferentes sitios. Los análisis expresaron bajas diferencias en la composición de especies entre ambos tipos de hábitats en el área. Conclusión: Los afloramientos rocosos y pendientes son ecosistemas importantes para la conservación y diversidad de los murciélagos en la región, ya que sus comunidades son regionalmente únicas.

Síndrome trófico trigeminal / Trigeminal trophic syndrome

El síndrome trófico trigeminal es una enfermedad infrecuente caracterizada por úlceras faciales autoprovocadas en regiones de anestesia o hipoestesia, secundarias al daño del nervio trigémino. Presentamos tres casos de este síndrome en seguimiento en nuestro centro.

Trigeminal trophic syndrome is an uncommon disease characterized by self-inflicted facial ulcers in anesthetic or hypoesthetic areas, secondary to trigeminal nerve damage. We present three cases in follow up at our hospital.