Nest refuse of Acromyrmex balzani (Hymenoptera: Formicidae) increases the plant vigor in Turnera subulata (Turneraceae) / O substrato de descarte de Acromyrmex balzani (Hymenoptera: Formicidae) aumenta o vigor da planta Turnera subulata (Turneraceae)

Some studies report the positive effect of organic residues from ant nests on soil properties and on the structure of the adjacent plant community in field experiments, but there is a gap about the effect on individual species. The purpose of the present study was to compare the soil nutrient content and the development of Turnera subulata Smith, an ornamental species, in the presence of the nest refuse (basically composed of fragments of grass leaves and the symbiotic fungus) produced by the leaf-cutting ant Acromyrmex balzani (Emery, 1890) or in control soil through a greenhouse pot experiment. The experiment was carried out with two treatments: control soil and soil with 25% of nest refuse. The plants were kept in 1L pots for 90 days. We evaluated the parameters: plant height, stem diameter, root length, number of leaves, dry weight of the root, dry and fresh aboveground biomass. Additionally, the relative chlorophyll content and leaf nutrients were used as nutritional parameters. As a result, plants that grew in the soil with nest refuse showed significant higher values of all parameters evaluated when compared to the control treatment (p < 0.001). We conclude that this biofertilizer contributed to the production of more vigorous plants, being able to act on the local dynamics of nutrients in the ecosystems where A. balzani occurs. As it is relatively abundant and easy to collect, the refuse of A. balzani has the potential to be used as an alternative substrate in the production of shortlife cycle plants.

Alguns estudos relatam o efeito positivo de resíduos orgânicos de formigueiros nas propriedades do solo e na estrutura da comunidade de plantas adjacentes em experimentos de campo, mas há uma lacuna sobre o efeito em espécies individuais. O objetivo do presente estudo foi comparar o desenvolvimento de Turnera subulata Smith, uma espécie ornamental, na presença do substrato de descarte (SD) de formigueiros produzido pela formiga cortadeira Acromyrmex balzani (Emery, 1890) por meio de experimento em casa de vegetação. O experimento foi conduzido com dois tratamentos: solo controle e solo com 25% de SD. As plantas foram mantidas em vasos de 1L por 90 dias. Foram avaliados os parâmetros: altura da planta, diâmetro do caule, comprimento da raiz, número de folhas, massa seca da raiz, biomassa seca e fresca da parte aérea. Além disso, o conteúdo relativo de clorofila e os nutrientes foliares foram usados como parâmetros fisiológicos. Como resultado, as plantas que cresceram no solo com SD apresentaram valores significativamente maiores de todos os parâmetros avaliados quando comparadas ao tratamento controle (p < 0.001). Concluímos que esse biofertilizante contribuiu para a produção de plantas mais vigorosas, podendo atuar na dinâmica local de nutrientes nos ecossistemas onde A. balzani ocorre. Além disso, por ser relativamente abundante e fácil de coletar, o SD de A. balzani tem potencial para ser utilizado como biofertilizante na produção de plantas de ciclo de vida curta.

Nest refuse of Acromyrmex balzani (Hymenoptera: Formicidae) increases the plant vigor in Turnera subulata (Turneraceae)

Abstract Some studies report the positive effect of organic residues from ant nests on soil properties and on the structure of the adjacent plant community in field experiments, but there is a gap about the effect on individual species. The purpose of the present study was to compare the soil nutrient content and the development of Turnera subulata Smith, an ornamental species, in the presence of the nest refuse (basically composed of fragments of grass leaves and the symbiotic fungus) produced by the leaf-cutting ant Acromyrmex balzani (Emery, 1890) or in control soil through a greenhouse pot experiment. The experiment was carried out with two treatments: control soil and soil with 25% of nest refuse. The plants were kept in 1L pots for 90 days. We evaluated the parameters: plant height, stem diameter, root length, number of leaves, dry weight of the root, dry and fresh aboveground biomass. Additionally, the relative chlorophyll content and leaf nutrients were used as nutritional parameters. As a result, plants that grew in the soil with nest refuse showed significant higher values of all parameters evaluated when compared to the control treatment (p 0.001). We conclude that this biofertilizer contributed to the production of more vigorous plants, being able to act on the local dynamics of nutrients in the ecosystems where A. balzani occurs. As it is relatively abundant and easy to collect, the refuse of A. balzani has the potential to be used as an alternative substrate in the production of shortlife cycle plants.

Resumo Alguns estudos relatam o efeito positivo de resíduos orgânicos de formigueiros nas propriedades do solo e na estrutura da comunidade de plantas adjacentes em experimentos de campo, mas há uma lacuna sobre o efeito em espécies individuais. O objetivo do presente estudo foi comparar o desenvolvimento de Turnera subulata Smith, uma espécie ornamental, na presença do substrato de descarte (SD) de formigueiros produzido pela formiga cortadeira Acromyrmex balzani (Emery, 1890) por meio de experimento em casa de vegetação. O experimento foi conduzido com dois tratamentos: solo controle e solo com 25% de SD. As plantas foram mantidas em vasos de 1L por 90 dias. Foram avaliados os parâmetros: altura da planta, diâmetro do caule, comprimento da raiz, número de folhas, massa seca da raiz, biomassa seca e fresca da parte aérea. Além disso, o conteúdo relativo de clorofila e os nutrientes foliares foram usados como parâmetros fisiológicos. Como resultado, as plantas que cresceram no solo com SD apresentaram valores significativamente maiores de todos os parâmetros avaliados quando comparadas ao tratamento controle (p 0.001). Concluímos que esse biofertilizante contribuiu para a produção de plantas mais vigorosas, podendo atuar na dinâmica local de nutrientes nos ecossistemas onde A. balzani ocorre. Além disso, por ser relativamente abundante e fácil de coletar, o SD de A. balzani tem potencial para ser utilizado como biofertilizante na produção de plantas de ciclo de vida curta.

Nest refuse of Acromyrmex balzani (Hymenoptera: Formicidae) increases the plant vigor in Turnera subulata (Turneraceae) / O substrato de descarte de Acromyrmex balzani (Hymenoptera: Formicidae) aumenta o vigor da planta Turnera subulata (Turneraceae)

Abstract Some studies report the positive effect of organic residues from ant nests on soil properties and on the structure of the adjacent plant community in field experiments, but there is a gap about the effect on individual species. The purpose of the present study was to compare the soil nutrient content and the development of Turnera subulata Smith, an ornamental species, in the presence of the nest refuse (basically composed of fragments of grass leaves and the symbiotic fungus) produced by the leaf-cutting ant Acromyrmex balzani (Emery, 1890) or in control soil through a greenhouse pot experiment. The experiment was carried out with two treatments: control soil and soil with 25% of nest refuse. The plants were kept in 1L pots for 90 days. We evaluated the parameters: plant height, stem diameter, root length, number of leaves, dry weight of the root, dry and fresh aboveground biomass. Additionally, the relative chlorophyll content and leaf nutrients were used as nutritional parameters. As a result, plants that grew in the soil with nest refuse showed significant higher values of all parameters evaluated when compared to the control treatment (p < 0.001). We conclude that this biofertilizer contributed to the production of more vigorous plants, being able to act on the local dynamics of nutrients in the ecosystems where A. balzani occurs. As it is relatively abundant and easy to collect, the refuse of A. balzani has the potential to be used as an alternative substrate in the production of shortlife cycle plants.

Resumo Alguns estudos relatam o efeito positivo de resíduos orgânicos de formigueiros nas propriedades do solo e na estrutura da comunidade de plantas adjacentes em experimentos de campo, mas há uma lacuna sobre o efeito em espécies individuais. O objetivo do presente estudo foi comparar o desenvolvimento de Turnera subulata Smith, uma espécie ornamental, na presença do substrato de descarte (SD) de formigueiros produzido pela formiga cortadeira Acromyrmex balzani (Emery, 1890) por meio de experimento em casa de vegetação. O experimento foi conduzido com dois tratamentos: solo controle e solo com 25% de SD. As plantas foram mantidas em vasos de 1L por 90 dias. Foram avaliados os parâmetros: altura da planta, diâmetro do caule, comprimento da raiz, número de folhas, massa seca da raiz, biomassa seca e fresca da parte aérea. Além disso, o conteúdo relativo de clorofila e os nutrientes foliares foram usados como parâmetros fisiológicos. Como resultado, as plantas que cresceram no solo com SD apresentaram valores significativamente maiores de todos os parâmetros avaliados quando comparadas ao tratamento controle (p < 0.001). Concluímos que esse biofertilizante contribuiu para a produção de plantas mais vigorosas, podendo atuar na dinâmica local de nutrientes nos ecossistemas onde A. balzani ocorre. Além disso, por ser relativamente abundante e fácil de coletar, o SD de A. balzani tem potencial para ser utilizado como biofertilizante na produção de plantas de ciclo de vida curta.

Effects of habitat loss on three insect assemblages in modified ecosystems of foothills of the Colombian Orinoquia / Efectos de la pérdida de hábitat en tres ensambles de insectos en ecosistemas modificados de Piedemonte en la Orinoquia colombiana

Abstract Introduction: The effects of habitat transformation have been widely studied and the effects are well-known at different levels of biological organization. However, few studies have focused on responses to this process at the level of multiple taxa in diverse taxonomic and functional groups. Objective: Determine the variations in taxonomic and functional diversity of ants, butterflies, and dung beetles, at a spatial and temporal level in a landscape mosaic of the ecoregion of the Colombian foothills. Methods: We assessed amount of natural habitat and landscape composition in four types of vegetation, during the highest and lowest rain periods. We collected butterflies with hand nets and used baited pitfall traps for dung beetles and ants. Results: Habitat loss positively affected ant and butterfly species richness, and negatively affected dung beetles. The abundance of ants and butterflies had a positive effect on the dominance of species in the transformed vegetation, for dung beetles the abundance was negatively affected by the absence of canopy cover. Habitat loss had no negative effect on functional diversity as there is no difference between natural and transformed vegetation. Conclusions: The amount of habitat, habitat connectivity and different types of vegetation cover were important factors in the maintenance of insect diversity in the modified ecosystems of foothills of the Colombian Orinoquia. The lack of a common spatial and temporal pattern shows that studies of multiple insect taxa should be carried out for biodiversity monitoring and conservation processes.

Resumen Introducción: Los efectos de la transformación del hábitat han sido ampliamente estudiados y son bien conocidos los efectos a diferentes niveles de organización biológica. Sin embargo, pocos estudios se han centrado en las respuestas a este proceso a nivel de múltiples taxones en diversos grupos taxonómicos y funcionales. Objetivo: Determinar las variaciones en la diversidad taxonómica y funcional de hormigas, mariposas y escarabajos coprófagos, a nivel espacial y temporal en un mosaico paisajístico de la ecorregión del piedemonte colombiano. Métodos: Evaluamos la cantidad de hábitat natural y la composición del paisaje en cuatro tipos de vegetación, durante los períodos de mayor y menor lluvia. Recolectamos mariposas con redes de mano y usamos trampas de caída con cebo para escarabajos coprófagos y hormigas. Resultados: La pérdida de hábitat afectó positivamente la riqueza de especies de hormigas y mariposas y afectó negativamente a los escarabajos peloteros. La abundancia de hormigas y mariposas tuvo un efecto positivo sobre la dominancia de especies en la vegetación transformada, para los escarabajos coprófagos la abundancia se vio afectada negativamente por la ausencia de cobertura de dosel. La pérdida de hábitat no tuvo un efecto negativo sobre la diversidad funcional ya que no hay diferencia entre la vegetación natural y la transformada. Conclusiones: La cantidad de hábitat, la conectividad del hábitat y los diferentes tipos de cobertura vegetal fueron factores importantes en el mantenimiento de la diversidad de insectos en los ecosistemas modificados del piedemonte de la Orinoquia colombiana. La falta de un patrón espacial y temporal común muestra que se deben realizar estudios de múltiples taxones de insectos para los procesos de monitoreo y conservación de la biodiversidad.

Remoción de semillas por Dorymyrmex insanus (Hymenoptera: Formicidae) en una reserva ecológica en la Ciudad de México, México / Seed removal by Dorymyrmex insanus (Hymenoptera: Formicidae) in an ecological reserve in Mexico City, Mexico

Abstract Introduction: Seed removal by ants is an interaction that may greatly affect the dynamic and structure of the vegetation. This aspect is well known for granivorous ants; however, there is little information on the effect of omnivorous ants. Objective: To assess the potential impact of the omnivorous ant Dorymyrmex insanus on vegetation. Methods: In the Pedregal Reserve, Mexico City, we identified the items in the refuse piles of ten ant colonies, for one year, covering the rainy and dry seasons. For each season we calculated seed diversity and analyzed the possible relationship between seed size and their abundance in the refuse piles, with regression models. We also did germination tests with seeds of Tagetes micrantha, comparing seeds from piles and from plants. Results: D. insanus removed seeds of 19 plant species as well as plant remains (such as leaves, twigs, roots), and remains of insects. Seed diversity was higher in the rainy season but the greatest abundance was in the dry season. When analyzing the relationship between seed length and abundance in the refuse piles, we found that the ants preferred seeds of around 10 mm. We also found that more seeds of T. micrantha germinated when they were previously handled by ants. Conclusions: The ant D. insanus actively participates in the removal of seeds from several species, favoring germination, and seasonality affects the selectivity of resources.

Resumen Introducción: La remoción de semillas por parte de las hormigas es una interacción que puede afectar en gran medida la dinámica y estructura de la vegetación. Este aspecto es bien conocido para las hormigas granívoras; sin embargo, hay poca información sobre el efecto de las omnívoras. Objetivo: Evaluar el impacto potencial de la hormiga omnívora Dorymyrmex insanus sobre la vegetación. Métodos: En la Reserva Pedregal, Ciudad de México, se identificaron los ítems en el área del basurero para diez colonias de hormigas, durante un año, cubriendo la época de lluvia y sequía. Para cada temporada calculamos la diversidad de semillas y analizamos la posible relación entre el tamaño de las semillas y su abundancia en los basureros, con modelos de regresión. También hicimos pruebas de germinación con semillas de Tagetes micrantha, comparando las encontradas en los basureros con las provenientes de las plantas. Resultados: D. insanus eliminó semillas de 19 especies de plantas, así como restos de plantas (hojas, ramitas, raíces) y restos de insectos. La diversidad de semillas fue mayor en la estación lluviosa pero la mayor abundancia lo fue en la estación seca. Al analizar la relación entre la longitud de las semillas y la abundancia en el área del basurero, encontramos que las hormigas preferían semillas de alrededor de 10 mm. También encontramos que germinaron más semillas de T. micrantha cuando fueron manipuladas previamente por hormigas. Conclusiones: La hormiga D. insanus participa activamente en la remoción de semillas de varias especies, favoreciendo la germinación, y la estacionalidad afecta la selectividad de recursos.

Effects of Layered Clothing on the Post-mortem Decomposition of Rat Carcasses on Grass Bushes and Dead Leaves (Kesan Pakaian Berlapis Terhadap Penguraian Postmortem Bangkai Tikus di atas Dedaun Rumput yang Telah Mati) / Jurnal Sains Kesihatan Malaysia

@#A post-mortem decomposition is defined by the evaluation of the physical and chemical changes of a cadaver or a carcass in order to estimate the cause of death and the time of death. The purpose of this study is not to replicate a real crime scene but to enhance knowledge of the effects of clothing in a decomposition process, mainly, the effects of layered cotton clothing on the post-mortem decomposition of adult female rat carcasses. Fifteen rats were divided into three groups: control, one-layered and two-layered clothed. The control subjects were unclothed and used to compare the post-mortem changes with the clothed subjects, one-layered and two-layered rat carcasses. All subjects were placed outdoor, 2.5 meters away from each other on grass bushes and dead leaves. Ambient temperature and humidity were recorded to observe if it associates with the post-mortem changes of the rats. Insect activity on each subject was observed. Post-mortem changes were measured using the Total Body Score system. The results showed that the control group underwent a faster decomposition compared to the clothed groups. The different layers of clothing did not show a vast difference in post-mortem changes. The ambient temperature of 28°C influences the post-mortem decomposition. The decomposition was rapid under the dominance of maggots compared to ants as ant colonies delayed the decomposition process. The study gave the knowledge of the effect of clothing in decomposition of female rats in forensic science.

Review of the Leptogenys unistimulosa species group (Hymenoptera: Formicidae) with the description of a new Amazonian species

ABSTRACT Leptogenys elzasoares new species, is described from workers and a male collected near Manaus in the Brazilian Amazon. The worker is recognizable by the presence of 12 chaetae (stout setae) on the clypeal median lobe, the straight mandible, and its bicolored body; the head and mesosoma are black while the gaster is brightly ferruginous. For the first time, the males of L. bohlsi Emery, 1896, L. unistimulosa Roger, 1863, and L. parensis Lattke, 2011 are described. A new key to the males of the unistimulosa species group is provided, and the key to workers of Lattke (2011) is updated to include the new species. Finally, we also report new records of L. parensis from French Guiana, expanding the known distribution by over 780 km northwest.

Mutualistic interaction of aphids and ants in pepper, Capsicum annuum and Capsicum frutenscens (Solanaceae) / Interacción mutualista de pulgones y hormigas en pimiento, Capsicum annuum y Capsicum frutenscens (Solanaceae)

Abstract Introduction: Adequate biological identification is fundamental for establishing integrated pest management programs and identifying the trophic and mutualist relationships that can affect pest population dynamics. Aphids are the main pest of pepper Capsicum spp. (Solanaceae) crops in Southwestern Colombia, due to their role as vectors of viruses. However, the identification of aphid species is complex, limiting the investigations performed to address their interactions with other organisms. Ants and aphids present a facultative mutualistic relationship, that promotes the growth of hemipteran colonies, for this reason, the study of the ecological mutualistic association between aphids and ants is important. Objective: The main objective was to discriminate the aphid species present in commercial crops of Capsicum spp., and to identify the ant community that attends the aphid colonies and its effects on the size of the aphid colonies. Methods: Aphid species, and their ant mutualist, were collected from Capsicum annuum and Capsicum frutescens, in the Cauca valley, Southwestern Colombia. We used the DNA barcoding approach to identify aphid species, and the ants were identified by morphology-based taxonomy. To evaluate the effect of ant care on the size and structure of aphid colonies, generalized linear models were calculated using as the response variables the total number of aphids for each colony and the proportion of nymphs. Results: The aphid species that attack pepper crops, are: Aphis gossypii and Myzus persicae (Hemiptera: Aphididae), with A. gossypii being the species that interacts with ants (19 ant species). A. gossypii colonies attended by ants had larger sizes and more nymphs per colony, than those not attended. Conclusions: Although the aphid-ant interaction is not species-specific, it is necessary to consider its role in the propagation of viral diseases in peppers and to determine how this interaction may affect regional biological control strategies.

Resumen Introducción: La adecuada identificación biológica es fundamental para establecer programas de manejo integrado de plagas e identificar las relaciones tróficas y mutualistas que pueden afectar la dinámica poblacional de insectos plaga. Los áfidos son las principales plagas del ají Capsicum spp. (Solanaceae) en el suroccidente colombiano, debido a su rol como vectores de virus. Sin embargo, su identificación es compleja, y limita las investigaciones que intentan revelar sus interacciones con otros organismos. Las hormigas y los áfidos presentan una relación mutualista facultativa, que promueve el crecimiento de las colonias de los hemípteros, por esta razón, el estudio de la asociación ecológica y mutualista entre áfidos y hormigas es importante. Objetivo: El principal objetivo de esta investigación fue discriminar las especies de áfidos presentes en cultivos comerciales de Capsicum spp., e identificar la comunidad de hormigas que atiende las colonias de áfidos y su efecto en el tamaño de las colonias de áfidos. Métodos: Los áfidos, y las hormigas mutualistas de estos áfidos, se recolectaron de Capsicum annuum y Capsicum frutescens, en el valle del rio Cauca, en el suroccidente colombiano. Se empleó el Código de barras del ADN para identificar las especies de áfidos, y las hormigas se identificaron empleando taxonomía basada en morfología. Para evaluar el efecto que tiene el cuidado de las hormigas sobre el tamaño de las colonias de áfidos, se empleó un modelo lineal generalizado, utilizando como variables de respuesta el número total de áfidos por cada colonia y la proporción de ninfas por colonia. Resultados: Las especies de áfidos que atacan los cultivos de ají, son: Aphis gossypii y Myzus persicae (Hemiptera: Aphididae), siendo A. gossypii la especie que interactúa con hormigas (19 especies). Las colonias de A. gossypii atendidas por hormigas presentan mayor tamaño y número de ninfas, que aquellas desatendidas. Conclusiones: Aunque la interacción áfido-hormiga no es especie específica, es necesario considerar su rol en la propagación de enfermedades virales en plantas cultivadas y determinar cómo esta interacción puede afectar la implementación de estrategias de control biológico.

Medically important ants: a systematic review of the global distribution and clinical consequences of their bites and stings / Hormigas de importancia médica: revisión sistemática de su distribución global y consecuencias clínicas de sus mordeduras y picaduras

Introduction: From the medical point of view, only some ants are of special interest. Due to the diversity of ants and the growing contact with humans, it is necessary to have a better understanding of the factors and problems, which lead to adverse clinical outcomes. Objective: The aim of this study was to conduct a systematic review of published studies on ants and their impact on the medical field to synthesize fragmented knowledge and to inform the current state of this problem. Methods: A systematic literature review was conducted in Medline, EMBASE, SciELO and Google Scholar, with no time threshold. The search strategy was limited to articles published in Portuguese, English and Spanish. Eligible studies were case reports and case series that reported outcomes in humans caused by ant stings. Patient-level and study-level information was extracted. Results: The literature search yielded 1909 studies; of which 30 case reports and 16 case series reporting a total of 95 cases were included. Of these 48 patients were women (50.5 percent, and the median age was 36.1 ± 25.5 years old. The most frequently reported complications were severe pain, anaphylaxis and acute respiratory distress syndrome. The death of eighteen patients was documented (18.9 percent). Ants from the genera Solenopsis spp., Myrmecia sp., Paraponera clavata, Pachycondyla sennaarensis, Myrmecia rubra caused most of the accidents Conclusions: Severe allergic reactions caused by ants are a rare event, however, mortality can be high. An increase of ant related accidents is expected, a quick diagnosis and treatment is necessary to avoid fatalities(AU)

Introducción: Desde el punto de vista médico, solo algunas hormigas son de especial interés. Debido a la diversidad de hormigas y al creciente contacto con humanos, es necesario comprender mejor los factores y problemas que conducen a resultados clínicos adversos. Objetivo: Realizar una revisión sistemática de estudios publicados sobre las hormigas y su impacto en el campo médico para sintetizar conocimientos fragmentados e informar sobre el estado actual del problema. Métodos: Se realizó una revisión bibliográfica sistemática en Medline, EMBASE, SciELO y Google Scholar, sin límite de tiempo. La estrategia de búsqueda se limitó a artículos publicados en portugués, inglés y español. Se seleccionaron informes y series de casos sobre consecuencias de las picaduras de hormigas en humanos. Se extrajo información a nivel de paciente y a nivel de estudio. Resultados: La búsqueda bibliográfica obtuvo 1 909 estudios, de los cuales se seleccionaron 30 informes y 16 series sobre un total de 95 casos. De estos, 48 pacientes eran mujeres (50,5 por ciento) y la media de edad era 36,1 ± 25,5 años. Las complicaciones más frecuentes fueron dolor intenso, anafilaxia y síndrome de dificultad respiratoria aguda. Se documentó la muerte de 18 pacientes (18,9 por ciento). Hormigas de los géneros Solenopsis spp., Myrmecia sp., Paraponera clavata, Pachycondyla sennaarensis y Myrmecia rubra causaron la mayoría de los accidentes. Conclusiones: Las reacciones alérgicas graves provocadas por hormigas son un evento raro; sin embargo, la mortalidad puede ser alta. Se espera un incremento de los accidentes relacionados con las hormigas. Se requiere un diagnóstico y tratamiento rápidos para evitar muertes(AU)

A 3D model to illustrate the nest architecture of Acromyrmex balzani (Hymenoptera; Formicidae)

ABSTRACT For eusocial insects, the nest is a place where the main social interactions occur. The nest architecture ensures protection from predators and the environment, as well as suitable conditions for brood rearing, food storage, and in some cases the cultivation of fungus farms. Variations in nest architecture can occur, according to the environmental conditions. In order to elucidate the internal organization of nests, most studies use 2D schemes and photographs to illustrate the nest architecture models. However, 3D models can provide a different and more realistic view of the nest architecture. The aim of this study was to describe the nest architecture and colony size of the grass-cutting ant Acromyrmex balzani (Emery), using 3D models to illustrate these features. The structures of eight colonies were measured and the data were used to create a 3D model of each nest. Externally, the nests had one or more piles of loose soil and waste, with a single straw turret over the entrance. Underground, the nests had from 2 to 6 chambers, at a maximum depth of 122 cm. It could be concluded that the observed nest architecture of Acromyrmex balzani followed, at least in part, the pattern already reported in the literature. However, this is the first report of connection between two chambers made by two shafts, as well as the presence of the turret at the nest entrance/exit, regardless of the season of the year. These differences evidence that the nest structures may vary, depending on intrinsic or local environmental conditions.

Flexibility in the integration of environmental information by Dinoponera quadriceps Kempf during foraging

Abstract Foraging behavior requires animals' behavioral flexibility to exhibit efficient strategies that result in the successful search for food. The navigation of ants enables long distance trips back and forth from the nest, using orientation cues. We analyzed the flexibility of Dinoponera quadriceps workers in integrating information introduced into the environment. We studied workers from two colonies in an area of secondary Atlantic Forest, with the use of a physical obstacle placed in front of the entrance of the nest with no fixed angular position. There was no significant difference in the resolution time workers to bypass the obstacle, in the angles between trips when exiting and returning to the nest, or in the positioning angles when returning to the nest. However, we found an increase in positioning angles when leaving the nest to search food, from the second contact onwards. They overcame the new obstacle as they would any other natural one. The presence of the obstacle did not prevent workers from maintaining route fidelity to individual areas. The behavior of D. quadriceps workers indicates that they have the flexibility to incorporate new information in a familiar environment. They likely use multimodal cues, which prevent them from wandering outside the familiar area.

First record of the association of the weevil Loncophorus longinasus with the fruit of munguba, Pseudobombax munguba in Central Amazonia, Brazil

We report the first record of occurrence of Loncophorus longinasus in fruits of munguba, Pseudobombax munguba, in the state of Amazonas, Brazil. Some morphological and biological aspects of L. longinasus are presented. Adults were obtained through natural emergence from munguba fruits that opened for seed dispersal. The fruits had perforations leading to galleries through the exocarp. Inside the fruit, larvae were found at the seed insertion points on the central seed attachment structure. The pupae developed in a cocoon at the same structure and turned mature simultaneously with the capsule opening. Together with the larvae, the presence of ants (Pseudomyrmex sp.) was observed, that apparently maintained the galleries open for access and feeding on larval exudates. (AU)

A new species of the Gnamptogenys Mordax subgroup (Hymenoptera: Formicidae), with an Identification key to the species within the subgroup

Abstract We describe, Gnamptogenys rugimala n. sp, a very distinct new species of the ectatommine genus Gnamptogenys, from specimens collected in forests of southeastern Brazil. We provide some data about G. rugimala n. sp occurrence and ecology as well as a species identification key for the mordax subgroup.

Nest Architecture Development of Grass-Cutting Ants, Atta capiguara (Hymenoptera: Formicidae)

ABSTRACT Atta capiguara grass-cutting ants are commonly found in the Cerrado biome, in open fields. Although grass-cutting ants build giant nests, little has been elucidated about this building pattern and when chambers and tunnels emerge. The present study describes the nest architecture development of A. capiguara grass-cutting ants from data on 31 cement-molded nests. A. capiguara nests grow with increases in the number of fungus chambers and emergence and increase of waste chambers and foraging tunnels. The structural growth of A. capiguara nests in the first year and a half of age (18 months) is vertical, with the building of the first chambers in the soil profile. After 18 months, the nests grow sideways with the addition of chambers and tunnels, and the first waste chambers appear. Between 18 and 54 months, the number of fungus chambers increases from 1-3 to 21-32, and the chambers are concentrated at the soil surface, although they can be found more than 3 m deep. In addition, the total volume of the waste chambers increases with the increment in the fungus chambers volume. Thus, this study contributes to understanding the nest architecture development of A. capiguara grass-cutting ants and demonstrates that the total volume of waste chambers is proportional to the total volume of fungus chambers suitable for the colony.

Fumigant toxicity and biochemical properties of (α + β) thujone and 1, 8-cineole derived from Seriphidium brevifolium volatile oil against the red imported fire ant Solenopsis invicta (Hymenoptera: Formicidae)

ABSTRACT The excessive use of chemical insecticides has led to negative effects on human health and the environment. Volatile oils are one of the possible potential alternatives to chemical insecticides. Traditionally Seriphidium brevifolium (Wall. ex DC.) Ling & Y.R.Ling, Asteraceae, powder from its leaves is used to treat gastric problems and expel intestinal worms by local peoples, but yet there is no literature available regarding its insecticidal activity. In this study fumigant toxicity and enzyme inhibition activities of the S. brevifolium volatile oil collected from the highlands of Skardu Baltistan, Pakistan, was evaluated against the red imported fire ant Solenopsis invicta. The phytochemical studies indicated that monoterpenes were the most abundant constituents, accounting for 88% of the total oil. The major dominant constituents were 2-bornanone (28.2%), 1,8-cineole (19.9%), α-thujone (7.5%), β-thujone (6.7%) which accounts for 62.3% of total constituents identified, with volatile oil yield of 4.11% (w/w). The fumigation assay indicated that the volatile oil was acutely toxic to fire ants, with an LC50 of 16.47 µl/l. Among the constituents tested, only (α + β) thujone and 1,8-cineole were toxic, with LC50 of 17.68 and 30.66 µl/ after 12 h of exposure. The volatile oil, (α + β) thujone and 1, 8-cineole showed strong fumigant activity against the red imported fire ant workers in a time- and dose-dependent manner. The volatile oil caused 100% mortality of the red imported fire ant workers, even at the lowest concentration of 20 µl/l after 24 h of exposure. In addition, the volatile oil and 1,8-cineole inhibited acetylcholinesterase activity, while (α + β) thujone inhibited carboxylesterase activity in the fire ant workers. It has been concluded that the volatile oil and some of the compounds from S. brevifolium might be developed as eco-friendly approaches for the control of red imported fire ants.

Bacterial extracts for the control of Atta cephalotes (Hymenoptera: Formicidae) and its symbiotic fungus Leucoagaricus gongylophorus (Agaricales: Agaricaceae)

Introduction: Leaf-cutting ants Atta cephalotes (Linnaeus) are one of the main insect pests in Latin America; these ants (along with Acromyrmex spp.) present a unique characteristic amongst ants, - the cultivation of the Leucoagaricus gongylophorus Möller (Singer) fungus as a food source. They belong to tribe Attini and build nests in underground chambers which are interconnected by pathways. These voracious ants have attacked over 45 crop fields in Colombia. The main control method has been the use of synthetic chemical products; however, alternative control measures must be established. One alternative that has a great potential are bacteria and their secondary metabolites. Objective: The aim of this study was to evaluate the insecticidal and antifungal effect of bacterial extracts on major worker A. cephalotes ants and the L. gongylophorus fungus. Methods: A total of 118 extracts produced by the same number of bacteria were evaluated. Among the strains that produced the active extracts were: Serratia sp., Xenorhabdus nematophila, Photorhabdus sp., and Bacillus thuringiensis. From each bacterium, extracts were prepared to test both insecticidal and repellent activity on worker ants, also to evaluate growth inhibition assays on L. gongylophorus. Results: Seventeen extracts showed insecticidal activity upon contact, 13 by ingestion, while 8 showed antifungal activity that was statistically significant. In total, 23 bacterial extracts exhibited some type of activity to control Atta cephalotes. Conclusions: The results show 23 bacterial extracts with some type of activity to control A. cephalotes, which exposes the potential there is to explore bacteria, especially entomopathogenic bacteria, which may contain interesting genes for the biological control of insects.

Introducción: Las hormigas cortadoras de hojas (Atta cephalotes) son una de las mayores plagas en América Tropical, estas hormigas (junto con Acromyrmex spp.) presentan una característica única entre las hormigas - el cultivo de un hongo como fuente de alimento (Leucoagaricus gongylophorus). Pertenecen a la tribu Attini y construyen sus nidos en cámaras subterráneas interconectadas por caminos. En el campo son muy voraces atacando más de 45 cultivos en Colombia. La metodología de control usada para el manejo de esta plaga ha sido principalmente el uso de productos químicos sintéticos, sin embargo, es importante establecer alternativas de control. Una fuente con gran potencial son las bacterias y sus metabolitos secundarios. Objetivo: El objetivo de la presente investigación fue evaluar la acción insecticida y antifúngica de los extractos bacterianos en obreras de A. cephalotes y el hongo L. gongylophorus. Métodos: Un total de 118 extractos, producidos por el mismo tipo de bacterias fueron evaluados. Resultados: Entre las cepas productoras se encontraban: Serratia sp., Xenorhabdus nematophila, Photorhabdus sp. y Bacillus thuringiensis. Diecisiete extractos mostraron actividad insecticida por contacto, 13 actividad por ingestión y 8 con actividad antifúngica estadísticamente significativa. En total 23 extractos bacterianos exhibieron algún tipo de actividad para el control de Atta cephalotes. Conclusiones: Los resultados muestran 23 extractos bacterianos con algún tipo de actividad hacia el control de A. cephalotes, los cuales exponen el potencial que hay para explorar bacterias, en especial las entomopatógenas. Estas bacterias pueden contener genes importantes para el control biológico de insectos.

¿Refleja Formicidae el impacto de la degradación de los bosques ribereños en la Amazonía Oriental?

La creciente presión antropogénica sobre la Amazonia Oriental hace imperativo el diagnóstico de la degradación forestal y, particularmente, su efecto sobre las comunidades clave dentro de los ecosistemas ribereños, unos de los últimos bosques amazónicos remantes en el estado de Maranhão. La familia de hormigas Formicidae juega un papel fundamental en el suelo, refleja los cambios en el uso de la tierra y es un grupo abundante en los bosques estudiados. Este trabajo tuvo como objetivo determinar el efecto del gradiente sucesional en la riqueza, frecuencia y composición de esta familia. El muestreo fue realizado durante los periodos seco y lluvioso con el método TSBF. Los organismos recolectados se identificaron a nivel de morfoespecies y se crearon curvas de acumulación de especies. Fueron utilizados modelos lineales mixtos para evaluar los efectos del periodo de recolecta local y estado de sucesión en la riqueza y la frecuencia de las hormigas. Por otro lado, se utilizaron regresiones polinómicas para investigar la relación entre la riqueza y la frecuencia de los formícidos según la cobertura del dosel y la altura de la vegetación. La composición de especies fue representada a través del índice de similitud de Jaccard. En total, 1 940 individuos fueron separados en 86 morfoespecies. Se obtuvo más del 80 % de la riqueza de especies probables. La frecuencia y riqueza de hormigas aumentó significativamente siguiendo la sucesión con valores bajos en las áreas abiertas durante la estación seca. Asimismo, durante esta estación, la cobertura del dosel y la altura de la vegetación tuvieron un efecto parcial en la riqueza y frecuencia de Formicidae. Por su parte, las áreas de sucesión intermedia y avanzada presentaron una composición similar con 50 especies compartidas, seguidas de las áreas de sucesión temprana con 43 y el uso antrópico con 34. Concluimos que la eliminación de los bosques ribereños tiene un efecto considerable sobre la riqueza y frecuencia de Formicidae, con valores mínimos en áreas degradadas durante la estación seca. Por otro lado, las áreas de bosques transformadas en sistemas agrícolas sufrieron pérdidas de 41 y 56% en la riqueza y frecuencia respectivamente. Con la sucesión, se restauran la estructura y las funciones del bosque favoreciendo la recolonización de las especies de hormigas. Finalmente, estos himenópteros son un grupo clave en los programas de monitoreo para la conservación/restauración de los bosques ribereños locales.

The increasing anthropogenic pressure on Eastern Amazon makes imperative the diagnosis of forest degradation, particularly the effect on key communities within the riparian ecosystems, one of the last remaining Amazonian forests in Maranhão State. The ant family Formicidae is an abundant group in these types of forests plays a fundamental role on the soil and also reflects the land use changes. Therefore, this study aimed to determine the impact of riparian forest successional stages on the Formicidae richness, frequency, and composition. Sampling was performed during both dry and wet seasons using the TSBF method. Collected organisms were identified as morphospecies. Also, species-accumulation curves were created. Linear mixed models were used to evaluate the effects of seasonal, local, and successional stage on ant richness and frequency. Polynomial regression models were applied to investigate the relationship between ant richness and frequency with canopy cover and vegetation height. Lastly, the species composition was represented by the Jaccard similarity index. In total, we observed 1 940 individuals grouped into 86 morphospecies. We obtained more than 80 % of the probable species richness. Ant frequency and richness increased significantly, following the successional stage, with low values in the open areas, especially during the dry season. Canopy cover and vegetation height seemed to affect partially both Formicidae richness and frequency during the dry season. Intermediate and advanced successional areas presented similar composition (50) shared species, followed by the areas of early succession (43) and anthropic use (34). We concluded that the elimination of riparian forests produces a considerable effect on the richness and frequency of the Formicidae family, minimally affecting them in open areas during the dry season, but resulting in losses of 41 % in richness and 56 % in frequency in forest areas when they are transformed into agricultural systems. Nevertheless, succession restores forest structure and functions, thus favoring re-colonization of ant species. Formicidae reflects forest degradation and is a key group in monitoring programs for the conservation/restoration of local riparian forests.

Foraging plasticity of Atta cephalotes (Hymenoptera: Formicidae) in response to temperature differences between forest and pasture

Introduction: Changes in microclimatic conditions due to land cover transformations influence variations in population life histories and the developmental patterns of organisms. These variations can have a genetic basis, an environmental basis, or both. Objective:To determine the differences between habitats in the foraging activity of Atta cephalotes in response to changes in temperature and the extent to which any such differences are due to phenotypic plasticity, genetic variability, or both.Methods:We performed foraging experiments; each colony (4 colonies sourced from pasture and 3 colonies sourced from forest) underwent eight temperature treatments from 10 to 45 ºC (± 1 ºC) at 5 ºC intervals, using common garden and reciprocal transplant experiments. Results:We found high plasticity in the foraging activity of Atta cephalotes in response to temperature, with the foraging activity gradually increasing from 15 to 35 ºC. Additionally, we found no significant differences in the foraging activity between the colonies sourced from the pasture and forest. Conclusions:The foraging activity of A. cephalotes was directly proportional to temperature, with ants exhibiting thermophilic behaviors and high plasticity, and there were no differences in the foraging activity between colonies sourced from both habitats.

Introducción: Los cambios en las condiciones microclimáticas debidos a la transformación de las coberturas vegetales genera variaciones en las historias de vida de las poblaciones y en los patrones de desarrollo de los organismos. Estas variaciones pueden tener bases genéticas, ambientales o ser el resultado de una interacción entre ambas. Objetivo: determinar las diferencias en la actividad de "forrajeo" de Atta cephalotes en respuesta a los cambios de temperatura en dos hábitats adyacentes y hasta qué grado estas diferencias son dadas por la plasticidad fenotípica, la variabilidad genética o la interacción de las dos. Métodología: se realizaron experimentos de "forrajeo"; cada colonia (4 colonias originarias de pasturas y 3 colonias originarias de bosque) se sometió a 8 tratamientos de temperatura de 10 a 45 ºC (± 1 ºC) a intervalos de 5 ºC usando experimentos de crianza común y transferencia recíproca. Resultados: se observó una alta plasticidad en la actividad de "forrajeo" de Atta cephalotes en respuesta a la temperatura, con un incremento gradual del "forrajeo" desde los hasta los 35 ºC. Adicionalmente no se encontraron diferencias significativas en la actividad de "forrajeo" entre las colonias originarias de la pastura y las del bosque. Conclusiones: la actividad de "forrajeo" de A. cephalotes, fue directamente proporcional a la temperatura, las hormigas mostraron un comportamiento termofílico y una alta plasticidad, y no hubo diferencias en la actividad de "forrajeo" entre colonias de los dos hábitats.

New records of three Neotropical arboreal ant species of Camponotus, subgenus Dendromyrmex (Hymenoptera: Formicidae) for the southern Amazon, including biological information / Novos registros de três espécies neotropicais de formigas arborícolas de Camponotus, subgênero Dendromyrmex (Hymenoptera: Formicidae) para a Amazônia meridional, incluindo dados de história natural

Camponotus (Formicinae) is the most specious and abundant genus of the family Formicidae. The genus is represented by ants that both forage and nest in the most diverse terrestrial and arboreal environments. Among the arboreal species of Camponotus are those of the subgenus Dendromyrmex. We recorded, for the first time, evidence of Camponotus chartifex (Smith, 1860) in the state of Mato Grosso, Brazil, and expanded the distributions of Camponotus nidulans (Smith, 1860) and Camponotus apicalis (Mann, 1916). We include information on the biology of the species and a discussion on the sampling of arboreal and winged ants. (AU)

Camponotus é um dos gêneros mais especiosos e abundantes da subfamília Formicidae. O gênero é representado por formigas que se alimentam e nidificam nos mais diversos habitats de ambientes terrestres e arbóreos. Entre as espécies arborícolas de Camponotus, estão as do subgênero Dendromyrmex. Registramos, pela primeira vez, Camponotus chartifex (Smith, 1860) para o estado de Mato Grosso, Brasil, e expandimos a distribuição de Camponotus nidulans (Smith, 1860) e Camponotus apicalis (Mann, 1916), incluindo informações biológicas sobre as espécies e uma discussão sobre a amostragem de formigas arborícolas e aladas.(AU)

A new species and new records of minuta-group Gnamptogenys from Brazil (Hymenoptera: Formicidae)

ABSTRACT We report new records of Gnamptogenys caelata Kempf (1967) and Gnamptogenys minuta (Emery, 1896) from Brazil. We also describe Gnamptogenys piei n. sp. from Southeast Brazil. This distinctive new species is known only from a single worker found in leaf litter from montane forests of the Mantiqueira mountains in Itatiaia National Park, Rio de Janeiro State, Brazil. The specimen was collected at 1991 m above sea level, an infrequent altitude for minuta-group ants, usually more common at lower altitudes. The new species is imaged, compared with other minuta-group species, and an updated identification key for all known species of the minuta-group is included.