Percentage of importance indice-production unknown: loss and solution sources identification on system / Percentagem de índice de importância-produção desconhecida: identificação de fontes de perda e de solução no sistema

Abstract Indices are used to help on decision-making. This study aims to develop and test an index, which can determine the loss (e.g., herbivorous insects) and solution (e.g., natural enemies) sources. They will be classified according to their importance regarding the ability to damage or to reduce the source of damage to the system when the final production is unknown. Acacia auriculiformis (Fabales: Fabaceae), a non-native pioneer species in Brazil with fast growth and rusticity, is used in restoration programs, and it is adequate to evaluate a new index. The formula was: Percentage of the Importance Indice-Production Unknown (% I.I.-PU) = [(ks1 x c1 x ds1)/Σ (ks1 x c1 x ds1) + (ks2 x c2 x ds2) + (ksn x cn x dsn)] x 100. The loss sources Aethalion reticulatum L., 1767 (Hemiptera: Aethalionidae), Aleyrodidae (Hemiptera), Stereoma anchoralis Lacordaire, 1848 (Coleoptera: Chrysomelidae), and Tettigoniidae, and solution sources Uspachus sp. (Araneae: Salticidae), Salticidae (Araneae), and Pseudomyrmex termitarius (Smith, 1877) (Hymenoptera: Formicidae) showed the highest % I.I.-PU on leaves of A. auriculiformis saplings. The number of Diabrotica speciosa Germar, 1824 (Coleoptera: Chrysomelidae) was reduced per number of Salticidae; that of A. reticulatum that of Uspachus sp.; and that of Cephalocoema sp. (Orthoptera: Proscopiidae) that of P. termitarius on A. auriculiformis saplings. However, the number of Aleyrodidae was increased per number of Cephalotes sp. (Hymenoptera: Formicidae) and that of A. reticulatum that of Brachymyrmex sp. (Hymenoptera: Formicidae) on A. auriculiformis saplings. The A. reticulatum damage was reduced per number of Uspachus sp., but the Aleyrodidae damage was increased per number of Cephalotes sp., totaling 23.81% of increase by insect damages on A. auriculiformis saplings. Here I show and test the % I.I.-PU. It is an new index that can detect the loss or solution sources on a system when production is unknown. It can be applied in some knowledge areas.

Resumo Índices são usados para ajudar na tomada de decisões. Este trabalho teve como objetivo desenvolver e testar um índice capaz de determinar fontes de perda (ex.: insetos herbívoros) e de solução (ex.: inimigos naturais). Eles serão classificados de acordo com sua importância quanto a habilidade de danificar ou reduzir danos no sistema, quando a produção final é desconhecida. Acacia auriculiformis (Fabales: Fabaceae), uma espécie pioneira não nativa do Brasil com rápido crescimento e rusticidade, usada em programas de restauração, é adequada para avaliar um novo índice. A fórmula foi: Porcentagem de Índice de Importância-Produção Desconhecida (% I.I.-PD) = [(ks1 x c1 x ds1)/Σ (ks1 x c1 x ds1) + (ks2 x c2 x ds2) + (ksn x cn x dsn)] x 100. As fontes de perda Aethalion reticulatum L., 1767 (Hemiptera: Aethalionidae), Aleyrodidae (Hemiptera), Stereoma anchoralis Lacordaire, 1848 (Coleoptera: Chrysomelidae) e Tettigoniidae, e as fontes de solução Uspachus sp. (Araneae: Salticidae), Salticidae (Araneae) e Pseudomyrmex termitarius (Smith, 1877) (Hymenoptera: Formicidae) apresentaram maiores % I.I.-PD nas folhas das mudas de A. auriculiformis. O número de Diabrotica speciosa Germar, 1824 (Coleoptera: Chrysomelidae) foi reduzido pelo número de Salticidae; o de A. reticulatum pelo de Uspachus sp.; e o de Cephalocoema sp. (Orthoptera: Proscopiidae) pelo de P. termitarius em mudas de A. auriculiformis. Entretanto, o número de Aleyrodidae foi aumentado pelo número de Cephalotes sp. (Hymenoptera: Formicidae) e o de A. reticulatum pelo de Brachymyrmex sp. (Hymenoptera: Formicidae) em mudas de A. auriculiformis. O dano de A. reticulatum foi reduzido pelo número de Uspachus sp., mas o dano de Aleyrodidae foi aumentado pelo número de Cephalotes sp., totalizando 23,81% de aumento de danos em mudas de A. auriculiformis. Aqui eu apresento e testo o % I.I.-PD. Ele é um novo índice capaz de detectar fontes de perda e de solução no sistema quando não se conhece a produção final. Ele pode ser aplicado em algumas áreas do conhecimento.

Riqueza y diversidad de hormigas (Hymenoptera: Formicidae) según uso de suelo en dos paisajes agroforestales de Colombia / Richness and diversity of ants (Hymenoptera: Formicidae) according to land use in two agroforestry landscapes of Colombia

Introducción: Las hormigas cumplen funciones ecológicas importantes en muchos ecosistemas, y son altamente sensibles a los cambios en el uso del suelo. Sin embargo, la respuesta ante estos cambios está poco documentada, a grandes escalas espaciales y en distintos usos de suelo, en ecosistemas poco estudiados como la Serranía del Perijá. Objetivo: Analizar la riqueza, diversidad y composición de las comunidades de hormigas en cuatro usos de suelo de dos paisajes agroforestales de la Serranía del Perijá, Cesar, Colombia. Métodos: En dos paisajes agroforestales (compensación y no compensación) se delimitaron dos ventanas de muestreo de 4 × 4 km. Dentro de cada ventana y paisaje se escogieron cuatro usos de suelo: bosques, sistemas agroforestales de café, regeneración natural y pastizales, en los cuales se aplicaron dos métodos de captura: trampas Pitfall y sacos Winkler. Se midieron seis variables ambientales: cobertura de dosel, altura de la hojarasca, densidad aparente, temperatura, humedad y dureza del suelo. El esfuerzo de muestreo fueron 384 trampas Pitfall y 192 m2 de extracción de hojarasca. El trabajo de campo se realizó entre febrero y marzo de 2021. Resultados: Las hormigas mostraron alta sensibilidad a los cambios en el uso del suelo. La diversidad y riqueza de especies disminuyó en los usos de suelo con menor cobertura vegetal natural, como los pastizales; mientras que los bosques, en ambos paisajes, conservaron la mayor riqueza de especies. La cobertura de dosel y la disponibilidad de hojarasca fueron los parámetros ambientales que favorecieron la diversidad y riqueza de las comunidades de hormigas en todos los usos de suelo. No se encontraron diferencias entre la composición de hormigas de los dos paisajes estudiados. Conclusiones: Las hormigas responden a los cambios de uso de suelo y en particular a la cobertura vegetal. Se confirmó nuestra hipótesis puesto que los usos de suelo con alta cobertura vegetal fueron los hábitats con mayor riqueza y diversidad de hormigas. La heterogeneidad ambiental, producto de la dinámica de transformación de los paisajes es un elemento que debe considerarse en futuras investigaciones.

Introduction: Ants fulfill important ecological functions in many ecosystems and are highly sensitive to changes in land use. However, the response to these changes is poorly documented, at large spatial scales and in different land uses, in poorly studied ecosystems such as the Serranía del Perijá. Objective: To analyze the richness, diversity, and composition of ant communities in four land uses of two agroforestry landscapes of the Serranía del Perijá, Cesar, Colombia. Methods: Two sampling windows of 4 × 4 km were delimited in two agroforestry landscapes (compensation and non-compensation). In each window and landscape four land uses were chosen: forests, coffee agroforestry systems, natural regeneration and pastures, in which two trapping methods were applied: Pitfall traps and Winkler bags. Six environmental variables were measured: canopy cover, leaf litter height, bulk density, temperature, humidity and soil hardness. The sampling effort was 384 Pitfall traps and 192 m2 of leaf litter extraction. The fieldwork was conducted between February and March 2021. Results: Ants showed high sensitivity to changes in land use. Species diversity and richness decreased in land uses with less natural vegetation cover, such as pastures; while forests, in both landscapes, retained the highest species richness. Canopy cover and leaf litter availability were the environmental parameters that favored the diversity and richness of ant communities in all land uses. No differences were found between the ant composition of the two landscapes studied. Conclusions: Ants respond to changes in land use, particularly to vegetation cover. Our hypothesis was confirmed since land uses with high vegetation cover were the habitats with the greatest richness and diversity of ants. Environmental heterogeneity, a product of the dynamics of landscape transformation, is an element that should be considered in future research.

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.

Ant diversity (Hymenoptera: Formicidae) in Turvo State Park, municipality of Derrubadas, state of Rio Grande do Sul, Brazil / Diversidade de formigas (Hymenoptera: Formicidae) no Parque Estadual do Turvo, Derrubadas, Rio Grande do Sul, Brasil

Abstract The knowledge of ant assemblages that occurs in Conservation Units in the Atlantic Forest domain is a priority, considering the number of endemic species and the impacts that this biome has been suffering. The aim of this study was to evaluate ant assemblages in the Turvo State Park, which is the largest conservation unit in the State of Rio Grande do Sul and presents an important role on biodiversity protection. Two samplings were conducted in 2019, one in the summer (January) and the other in the spring (November and December), at five sites 2 km apart, with pitfall traps (soil and canopy), sardine baits, glucose, beating net, sweeping net and manual collection. We sampled 121 species in the summer and 120 in the spring, totaling 163 ant species. A total of 78 species (47.8%) occurred in both sampling seasons. The richest genera in the study were Camponotus (S = 30), Pheidole (S = 23) and Linepithema (S = 11). Seventeen species were recorded for the first time for Rio Grande do Sul state. The results indicate that this is one of the most species-rich assemblages of ants ever surveyed in a conservation unit in southern Brazil. The study highlights the importance of Conservation Units as protected environments against habitat loss for ant biodiversity. The results of this study contribute to myrmecofauna knowledge and serve as a basis for environmental impact studies, management plans and conservation of Atlantic Forest remnants.

Resumo O conhecimento das assembleias de formigas que ocorrem em Unidades de Conservação no domínio Mata Atlântica é prioritário, considerando-se o número de espécies endêmicas e os impactos que este bioma vem sofrendo. O objetivo desse trabalho foi caracterizar a assembleia de formigas que ocorre no Parque Estadual do Turvo, a maior unidade de conservação do Rio Grande do Sul que se destaca pelo seu papel na proteção da biodiversidade da Mata Atlântica austral. Foram realizadas duas amostragens no ano de 2019, uma no verão (janeiro) e a outra na primavera (novembro e dezembro), em cinco pontos distantes 2 km entre si, com armadilhas pitfall (solo e dossel), iscas de sardinha, iscas de glicose, guarda-chuva entomológico, rede de varredura e coleta manual. A riqueza amostrada no verão foi de 121 e na primavera de 120, totalizando 163 espécies. Ao todo, 78 espécies (47,8%) ocorreram concomitantemente nas duas amostragens. Os gêneros mais ricos foram Camponotus (S=30), Pheidole (S=23) e Linepithema (S=11). Dezessete espécies foram registradas pela primeira vez para o estado do Rio Grande do Sul. Os resultados se constituem em uma das mais ricas assembleias de formigas já inventariadas em uma unidade de conservação na região sul do Brasil. O estudo destaca a importância das Unidades de Conservação como ambientes protegidos contra a perda de habitat para a biodiversidade de formigas. Os resultados deste estudo contribuem para o conhecimento da mirmecofauna e servem como base para estudos de impacto ambiental, planos de manejo e conservação de remanescentes da Mata Atlântica.

Arthropod fauna on the abaxial and adaxial surfaces of Acacia mangium (Fabaceae) leaves / Fauna de artrópodes nas superfícies abaxial e adaxial de folhas de Acacia mangium (Fabaceae)

Abstract Acacia mangium (Willd., 1806) (Fabales: Fabaceae) is a fast growing, rustic, pioneer species, with potential to fix nitrogen, and for programs to recover degraded areas. The objective was to evaluate the distribution and the functional diversity of interactions and the K-dominance of arthropod groups on A. mangium saplings. The number of individuals of eleven species of phytophagous insects, three bee species, and fourteen natural enemy species were highest on the adaxial leaf surface of this plant. Abundance, diversity and species richness of phytophagous insects and natural enemies, and abundance and species richness of pollinators were highest on the adaxial A. mangium leaf surface. The distribution of five species of sap-sucking hemipterans and six of protocooperating ants (Hymenoptera), with positive interaction between these groups, and three bee species (Hymenoptera) were aggregated on leaves of A. mangium saplings. Aethalion reticulatum (L.) (Hemiptera: Aethalionidae) and Bemisia sp. (Hemiptera: Aleyrodidae); Brachymyrmex sp. and Camponotus sp. (Hymenoptera: Formicidae); and Trigona spinipes Fabricius (Hymenoptera: Apidae) were the most dominant phytophagous insects, natural enemies, and pollinators, respectively, on A. mangium leaves. Knowledge of preferred leaf surfaces could help integrated pest management programs.

Resumo Acacia mangium (Willd., 1806) (Fabales: Fabaceae) é uma planta pioneira com rápido crescimento, rusticidade, potencial nitrificador e importante em programas de recuperação de áreas degradadas. O objetivo foi avaliar a distribuição e a diversidade funcional das interações e a dominância-K de grupos de artrópodes em árvores jovens de A. mangium. Os números de indivíduos de onze espécies de insetos fitófagos, três de abelhas e quatorze de inimigos naturais foram maiores na superfície adaxial de folhas dessa planta. A abundância, diversidade e riqueza de espécies de insetos fitófagos e inimigos naturais, e a abundância e riqueza de espécies de polinizadores foram maiores na face adaxial de folhas de A. mangium. A distribuição de cinco espécies de hemípteros sugadores de seiva e seis de formigas protocooperantes (Hymenoptera), com interação positiva entre esses grupos, e três de abelhas (Hymenoptera) foi agregada em folhas de plantas jovens de A. mangium. Aethalion reticulatum (L.) (Hemiptera: Aethalionidae) e Bemisia sp. (Hemiptera: Aleyrodidae); Brachymyrmex sp. e Camponotus sp. (Hymenoptera: Formicidae); e Trigona spinipes Fabricius (Hymenoptera: Apidae) foram os insetos fitófagos, inimigos naturais e polinizadores mais dominantes, respectivamente, em folhas de A. mangium. A definição da superfície foliar preferida pode auxiliar programas de manejo integrado de pragas.

Distribution pattern of arthropods on the leaf surfaces of Acacia auriculiformis saplings / Padrão de distribuição de artrópodes nas superfícies foliares de plantas de Acacia auriculiformis

Abstract Acacia auriculiformis A. Cunn. Ex Benth. (Fabaceae), a non-native pioneer species in Brazil with fast growth and rusticity, is used in restoration programs. Our goal was to assess during a 24-month survey the pattern of arthropods (phytophagous insects, bees, spiders, and predator insects) on the leaf surfaces of A. auriculiformis saplings. Fourteen species of phytophagous, two of bees and eleven of predators were most abundant on the adaxial surface. The values of the ecological indexes (abundance, diversity, and species richness) and the rarefaction, and k-dominance curves of phytophagous, bees and arthropod predators were highest on the adaxial leaf surface of A. auriculiformis. The k-dominance and abundance of Aleyrodidae (Hemiptera) (both leaf surfaces), the native stingless bee Tetragonisca angustula Latreille (Hymenoptera: Apidae) (both leaf surfaces) and the ant Brachymyrmex sp. (adaxial surface) and Pheidole sp. (Hymenoptera: Formicidae) (abaxial surface) were the highest between the taxonomic groups of phytophagous, bees, and predators, respectively on A. auriculiformis saplings. The ecological indexes and rarefaction, abundance, and k-dominance curves of phytophagous insects, bees, and predators were highest on the adaxial leaf surface. The preference of phytophagous insects for the adaxial leaf surface is probably due to the lower effort required to move on this surface. Understanding the arthropod preferences between leaf surfaces may help to develop sampling and pest management plans for the most abundant phytophagous insects on A. auriculiformis saplings. Also, knowledge on the preference pattern of bees and predators may be used to favour their conservation.

Resumo Acacia auriculiformis A. Cunn. Ex Benth. (Fabaceae), espécie pioneira com rápido crescimento e rusticidade, é utilizada em programas de recuperação de áreas degradadas. O objetivo deste trabalho foi avaliar, durante 24 meses, o padrão de distribuição de artrópodes (insetos fitófagos, abelhas, aranhas e insetos predadores) nas superfícies foliares de A. auriculiformis. Quatorze espécies de fitófagos, duas de abelhas e onze de predadores foram mais abundantes na superfície adaxial. Índices ecológicos (abundância, diversidade e riqueza de espécies) e curvas de rarefação e dominância-k de fitófagos, abelhas e artrópodes predadores foram maiores na face adaxial de folhas de A. auriculiformis. A dominância-k e a abundância de Aleyrodidae (Hemiptera) (ambas as superfícies foliares), da abelha nativa sem ferrão Tetragonisca angustula Latreille (Hymenoptera: Apidae) (ambas as superfícies foliares) e das formigas Brachymyrmex sp. (superfície adaxial) e Pheidole sp. (Hymenoptera: Formicidae) (superfície abaxial) foram as maiores entre os grupos taxonômicos de fitófagos polinizadores e predadores, respectivamente, em plantas jovens de A. auriculiformis. A abundância, diversidade e riqueza e as curvas de rarefação e dominância-k de artrópodes fitófagos, abelhas e predadores foram maiores nas superfícies adaxiais das folhas dessa árvore. A preferência pela superfície adaxial da folha se deve, provavelmente, ao menor esforço para se movimentarem na mesma. Compreender as preferências dos artrópodes pelas superfícies foliares pode auxiliar no desenvolvimento de planos de amostragem e manejo de pragas em A. auriculiformis. Além disso, o conhecimento da distribuição de abelhas e predadores pode favorecer a conservação desses insetos.

Ant diversity (Hymenoptera: Formicidae) in Turvo State Park, municipality of Derrubadas, state of Rio Grande do Sul, Brazil / Diversidade de formigas (Hymenoptera: Formicidae) no Parque Estadual do Turvo, Derrubadas, Rio Grande do Sul, Brasil

The knowledge of ant assemblages that occurs in Conservation Units in the Atlantic Forest domain is a priority, considering the number of endemic species and the impacts that this biome has been suffering. The aim of this study was to evaluate ant assemblages in the Turvo State Park, which is the largest conservation unit in the State of Rio Grande do Sul and presents an important role on biodiversity protection. Two samplings were conducted in 2019, one in the summer (January) and the other in the spring (November and December), at five sites 2 km apart, with pitfall traps (soil and canopy), sardine baits, glucose, beating net, sweeping net and manual collection. We sampled 121 species in the summer and 120 in the spring, totaling 163 ant species. A total of 78 species (47.8%) occurred in both sampling seasons. The richest genera in the study were Camponotus (S = 30), Pheidole (S = 23) and Linepithema (S = 11). Seventeen species were recorded for the first time for Rio Grande do Sul state. The results indicate that this is one of the most species-rich assemblages of ants ever surveyed in a conservation unit in southern Brazil. The study highlights the importance of Conservation Units as protected environments against habitat loss for ant biodiversity. The results of this study contribute to myrmecofauna knowledge and serve as a basis for environmental impact studies, management plans and conservation of Atlantic Forest remnants.

O conhecimento das assembleias de formigas que ocorrem em Unidades de Conservação no domínio Mata Atlântica é prioritário, considerando-se o número de espécies endêmicas e os impactos que este bioma vem sofrendo. O objetivo desse trabalho foi caracterizar a assembleia de formigas que ocorre no Parque Estadual do Turvo, a maior unidade de conservação do Rio Grande do Sul que se destaca pelo seu papel na proteção da biodiversidade da Mata Atlântica austral. Foram realizadas duas amostragens no ano de 2019, uma no verão (janeiro) e a outra na primavera (novembro e dezembro), em cinco pontos distantes 2 km entre si, com armadilhas pitfall (solo e dossel), iscas de sardinha, iscas de glicose, guarda-chuva entomológico, rede de varredura e coleta manual. A riqueza amostrada no verão foi de 121 e na primavera de 120, totalizando 163 espécies. Ao todo, 78 espécies (47,8%) ocorreram concomitantemente nas duas amostragens. Os gêneros mais ricos foram Camponotus (S=30), Pheidole (S=23) e Linepithema (S=11). Dezessete espécies foram registradas pela primeira vez para o estado do Rio Grande do Sul. Os resultados se constituem em uma das mais ricas assembleias de formigas já inventariadas em uma unidade de conservação na região sul do Brasil. O estudo destaca a importância das Unidades de Conservação como ambientes protegidos contra a perda de habitat para a biodiversidade de formigas. Os resultados deste estudo contribuem para o conhecimento da mirmecofauna e servem como base para estudos de impacto ambiental, planos de manejo e conservação de remanescentes da Mata Atlântica.

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.

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.

Basic ecology of ant gardens in a dry-premontane transitional forest / Ecología básica de jardines de hormigas en un bosque transicional seco-premontano

Abstract Introduction: "Ant gardens'' are ant nests located at different heights on trees on which vascular epiphytic plants that have been transported and sown by ants have germinated. Although this mutualistic relationship has been studied in humid tropical ecosystems, information on other tropical and Colombian ecosystems is scarce. Objective: To characterize the distribution, building, diversity, demography and phenology of ant gardens in dry tropical forest. Methods: In January and February, 2018, we identified 170 ant gardens on a 100x5 m transect on the banks of the Quesada River, Colombia, and in adjacent secondary dry premontane transitional forest; we monitored changes, for gardens and plants, in 28 of them, every two weeks (March 2018-February 2019). Results: The gardens, built by Azteca ulei, were aggregated near water bodies; had 10 species of epiphytes and were on 13 tree species. Larger gardens had more epiphyte species. Some epiphytes had a bimodal phenological pattern. Less seedlings become established in the dry season, and less adults remain in the gardens. Garden characteristics benefit both epiphytes and ants. Conclusions: The gardens built by A. ulei have ecological characteristics that favor the germination, establishment, and reproduction of diverse epiphytes in this dry tropical ecosystem, including aggregation near water flows.

Resumen Introducción: Los "jardines de hormigas'' son nidos de hormigas en árboles, que se localizan a diferentes alturas, sobre los que germinan plantas epífitas vasculares que han sido transportadas y sembradas previamente por hormigas. Aunque esta relación mutualista ha sido estudiada en ecosistemas húmedos tropicales, la información en otros ecosistemas tropicales y en Colombia, es escasa. Objetivo: Caracterizar la distribución, construcción, diversidad, demografía y fenología de los hormigueros en bosque tropical seco. Métodos: En enero y febrero de 2018, identificamos 170 hormigueros en un transecto de 100x5 m a orillas del río Quesada, Colombia, y en el bosque secundario premontano seco de transición adyacente; monitoreamos cambios, para jardines y plantas, en 28 de ellos, cada dos semanas (marzo 2018-febrero 2019). Resultados: Los jardines, construidos por Azteca ulei, se agregaron cerca de cuerpos de agua; tenían 10 especies de epífitas y estaban sobre 13 especies arbóreas. Los jardines más grandes tenían más especies epífitas. Algunas epífitas tuvieron un patrón fenológico bimodal. Se establecen menos plántulas en la estación seca y quedan menos adultos en los jardines. Las características del jardín benefician tanto a las epífitas como a las hormigas. Conclusiones: Los jardines construidos por A. ulei tienen características ecológicas que favorecen la germinación, establecimiento y reproducción de diversas epífitas en este ecosistema tropical seco, incluyendo la agregación cerca de cursos de agua.

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 the pesticides chlorpyriphos, metsulfuron-methyl, and thiamethoxam on ant communities in wheat crop

Ants are important components of food webs in several ecosystems. In anthropic areas, they can be used as bioindicators of the environmental impacts caused by many factors or in the evaluation of the dynamics of the recovery of an area after a certain disturbance. In this context, ants can be used as bioindicators in studies on the evaluation of environmental disturbances caused by pesticide use. Thus, the present work investigated the environmental impacts caused by the application of the insecticides chlorpyriphos and thiamethoxam and the herbicide metsulfuron-methyl in the community of ants in wheat crop (Triticum aestivum L.). The data were collected by pitfall traps and Berlese funnels. A Principal Response Curve was used for a relative abundance analysis. In addition, diversity index and richness were calculated for ant communities. The presence of six families, 11 tribes, 15 genera, and 19 morphospecies of ants belonging to the guilds of fungivorous, omnivorous, and predaceous ants were observed in the soil of the wheat crop. The insecticides chlorpyriphos and thiamethoxam reduced the richness, diversity, and relative abundance of ants of all the guilds on the surface and inside the soil. The effect of the herbicide metsulfuron-methyl on the community of ants was lower than the impact of the insecticides on these insects.

Bacterial communities of big-headed ants (Pheidole rugaticeps) and American cockroaches (Periplaneta americana) revealed pathogens of public health importance

Aims@#Several cockroach and ant species have been revealed to infest households with inadequate insect control and food storage practices. These household insects harbor countless bacteria species of public health, agricultural and industrial importance. Many studies have reported disease-causing bacteria from both cockroaches and ant’s species collected from hospitals and residential areas. The aim of this study was to characterize the culturable bacterial communities of two common household insects, big headed ants (Pheidole rugaticeps) and American cockroaches (Periplaneta americana) using 16S rRNA genes sequencing.@*Methodology and results@#A total of 64 bacterial sequences were obtained from P. rugaticeps (48.44%) and P. americana (51.56%) and Firmicutes was the most dominant phylum from both insect species. Bacillus was the most dominant bacterial genus from both cockroach and ant samples. Other important genera isolated were Pseudomonas and Stenotrophomonas which have previously been suggested to have members that are of biotechnological importance. Food poisoning bacterial species, B. cereus and other bacterial strains such as B. subtilis, Acinetobacter baumannii, Burkholderia cepacia, P. aeruginosa, Staphylococcus epidermidis, Serratia marcescens and S. pseudintermedius with the history of human infections were isolated from some of the insect’s specimens.@*Conclusion, significance and impact of study@#Thus, these household insect pests harbor bacterial species known to cause diseases of serious public health importance that needs serious attentions. Similarly, the insects harbor other bacteria species that may provide opportunities for biotechnological exploration.

Trap rebuilding by Myrmeleon brasiliensis larvae (Neuroptera: Myrmeleontidae) in response to flooding: the effect of body size / Reconstrucción de trampas por larvas de Myrmeleon brasiliensis (Neuroptera: Myrmeleontidae) tras las inundaciones: efecto del tamaño corporal

Abstract Introduction: Immature forms of the antlion Myrmeleon brasiliensis (Neuroptera, Myrmeleontidae) build traps in dry sandy soil to capture prey. Objective: The aim of the present study was to investigate how the waterlogging of the soil due to rain affects the trap rebuilding and relocation behavior of M. brasiliensis of different sizes. Methods: The study was conducted between July and December 2019. Larvae M. brasiliensis were observed and collected from a forest reserve in the municipality of Aquidauana in the state of Mato Grosso do Sul, Brazil. Results: In the natural environment, most larvae rebuilt their traps in the same location seven days after the simulation of rain, with a smaller diameter than that observed prior to the simulation of rain. In the laboratory, the movements of M. brasiliensis larvae and rebuilding of the traps after the waterlogging of the soil was affected by body size. Larger larvae moved more and were more likely to rebuild their traps. Conclusions: The saturation of the soil affects the foraging of M. brasiliensis larvae, which are impeded from rebuilding their traps for a period. In situations of long periods of saturated soil, the mortality rate of the larvae is high and rebuilding of the traps occurs after the soil dries out, but with a smaller trap size. These data suggest that changes in the rainfall pattern can affect the population structure of M. brasiliensis larvae, with the selection of larger individuals in situations of more severe rains. In this process, the smaller larvae are more affected, as their foraging is impeded.

Resumen Introducción: Los insectos inmaduros de hormiga león de la especie Myrmeleon brasiliensis (Neuroptera, Myrmeleontidae), construyen trampas en el suelo arenoso seco para capturar a sus presas. Objetivo: El objetivo de este trabajo fue analizar cómo la inundación del suelo, como la lluvia, afecta al comportamiento de reconstrucción y de desplazamiento de las trampas de M. brasiliensis según las diferentes tallas. Métodos: El estudio fue conducido entre julio y diciembre del 2019. Las larvas fueron observadas y recolectadas en una Reserva Forestal en la ciudad de Aquidauana, Estado de Mato Grosso del Sur, Brasil. Resultados: Observamos que, en el ambiente natural, siete días después de la lluvia simulada, la mayoría de las larvas reconstruyeron a sus trampas en el mismo sitio y con diámetro más pequeño que el observado antes de la lluvia simulada. En el laboratorio fue observado que después de la inundación del suelo, el desplazamiento de las larvas y la reconstrucción de las trampas es afectado por el tamaño de su cuerpo. Así, larvas de M. brasiliensis más grandes se desplazan más y presentan una probabilidad más grande de reconstruir a sus trampas. Conclusión: De esa manera, la inundación del suelo afecta el forrajeo de las larvas M. brasiliensis, que se quedan impedidas por un tiempo durante la reconstrucción de sus trampas. Además, en situaciones de largos periodos de inundación del suelo, las larvas presentan una alta tasa de mortalidad y la reconstrucción de sus trampas ocurre después que se seca el suelo, pero esas trampas suelen ser más pequeñas. Esos datos sugieren que es posible que variaciones en el patrón de lluvia pueden afectar la estructura poblacional de las larvas M. brasiliensis, pues en situaciones de lluvias más fuertes, las larvas más grandes suelen tener más éxito. En este proceso, las larvas más pequeñas se ven más afectadas, ya que se impide su búsqueda de alimento.

Ant diversity sampling in the Brazilian Amazon: a comparison of litter collection and pitfall trapping / Muestreo de la diversidad de hormigas en la Amazonía brasileña: una comparación de recolección de hojarasca y trampas de caída

Abstract Introduction: Ants in tropical forests are a hyper-diverse group that plays important ecological roles. Several studies on tropical forests have used different sampling protocols to capture soil ants, making it difficult to compare responses and patterns of diversity between studies. Thus, research that compares different well-structured and standardized sampling methodologies to adequately estimate the richness of ant species in tropical forests is necessary. Objective: In this study, we examined the combination of catches with pitfall traps with and without baits and litter collections for soil ant sampling. Methods: In the fall traps, we use two baited (sardines and bananas) and one non-baited. For the manual collections (litter sampling), the litter and only the topsoil of the loose soil were collected. Results: We found that traps containing sardine baits collected a greater abundance of ants, whereas non-baited traps collected a greater richness of ant species. On the other hand, litter collections captured the largest number of exclusive species, presenting a different species composition from the pitfall traps (with and without baits). In general, baited traps showed greater abundance in more degraded locations, while manual collections and unbaited pitfalls captured more individuals in preserved environments. Conclusions: Our results provide evidence that, for accurate sampling of soil ant assemblages in tropical forests, the use of different methodologies is necessary to capture a greater diversity of species because the methods differ in effectiveness according to habitat.

Resumen Introducción: Las hormigas en los bosques tropicales son un grupo hiperdiverso que juega un papel ecológico importante. Varios estudios en los bosques tropicales han utilizado diferentes protocolos de muestreo para capturar las hormigas de suelo, lo que dificulta la comparación de respuestas y patrones de diversidad entre estudios. Por lo tanto, es necesaria una investigación que compare diferentes metodologías de muestreo bien estructuradas y estandarizadas para estimar adecuadamente la riqueza y uniformidad de las especies de hormigas en los bosques tropicales. Objetivo: En este estudio, examinamos la combinación de capturas con trampas de caída con y sin cebos y recolecciones manuales para muestreo de hormigas en el suelo. Métodos: En las trampas de otoño, utilizamos dos cebos (sardinas y plátanos) y uno sin cebo. Para las recolecciones manuales (muestreo de hojarasca), se recogió la hojarasca y solo la capa superior de suelo suelto. Resultados: Encontramos que las trampas que contenían cebos de sardina recolectaron una mayor abundancia de hormigas, mientras que las trampas sin cebo recolectaron una mayor riqueza de especies de hormigas. Por otro lado, las recolecciones de hojarasca capturaron el mayor número de especies exclusivas, presentando una composición de especies diferente a las trampas de caída (con y sin cebo). En general, las trampas con cebo mostraron mayor abundancia en lugares más degradados, mientras que las recolecciones manuales y las trampas sin cebo capturaron más individuos en ambientes preservados. Conclusiones: Nuestros resultados proporcionan evidencia de que, para un muestreo preciso de ensambles de las hormigas de suelo en los bosques tropicales, el uso de diferentes metodologías es necesario para capturar una mayor diversidad de especies, ya que los métodos difieren en la efectividad de acuerdo con el hábitat.