Diversity of the Anisoptera & Zygoptera (Odonata: Insecta) of Swat, Pakistan

Abstract Odonates are important biological control agents for the control of insect pests and insect disease vectors of medical and veterinary importance. The present study was conducted to evaluate the odonate fauna of Swat, Pakistan from March to October 2019. A total of 200 specimens of odonates were collected from diverse habitats. The collected specimens of the order Odonata belonged to 5 families, three families of suborder Anisoptera namely Libellulidae, Gomphidae and Aeshnidae while two families of suborder Zygoptera (Chlorocyphidae and Coenagrionidae). The specimens were categorized into 12 genera and 22 species. Libellulidae was the dominant family (n = 138) accounting for 69% of the odonate fauna. Orthetrum was the dominant genus (n = 73) of suborder Anisoptera accounting for 36.5% of the odonate fauna. The least dominant genera were Anax, Paragomphus and Rhyothemis (n = 5 each) accounting each for 2.5% of the odonate fauna. In Zygoptera, the dominant genus was Ceriagrion (12.5%) and the least dominant genus was Ischnura (6%). Pantala flavescens (Fabricius, 1798) was the most abundant odonate species in the study area recorded from all surveyed habitats. Shannon Diversity Index (H) was 2.988 and Simpson Diversity Index (D) was 0.95 for the collected odonate fauna. The highest abundance of Odonata was recorded in August, September and May while no odonate species were recorded in January, February, November and December. Lotic water bodies were the most suitable habitats with abundant odonate fauna. Anax immaculifrons (Rambur, 1842) was the largest sized odonate species having a wingspan of 53.2±1.63 mm and body length of 56.3 ± 0.4 mm. The present study shows the status of odonate fauna of Swat, Pakistan in diverse habitats and seasonsonal variation throughout the year. Further work is recommended to bridge the gaps in the existing literature.

Resumo Odonatos são importantes agentes de controle biológico para o controle de insetos-praga e vetores de doenças de insetos de importância médica e veterinária. O presente estudo foi conduzido para avaliar a fauna de odonatos de Swat, Paquistão, de março a outubro de 2019. Um total de 200 espécimes de odonatos foi coletado em diversos habitats. Os espécimes coletados da ordem Odonata pertenciam a cinco famílias, três famílias da subordem Anisoptera, a saber, Libellulidae, Gomphidae e Aeshnidae, enquanto duas famílias eram da subordem Zygoptera (Chlorocyphidae e Coenagrionidae). Os espécimes foram classificados em 12 gêneros e 22 espécies. Libellulidae foi a família dominante (n = 138), respondendo por 69% da fauna de odonatos. Orthetrum foi o gênero dominante (n = 73) da subordem Anisoptera, responsável por 36,5% da fauna de odonatos. Os gêneros menos dominantes foram Anax, Paragomphus e Rhyothemis (n = 5 cada), representando cada um 2,5% da fauna de odonatos. Em Zygoptera, o gênero dominante foi Ceriagrion (12,5%), e o gênero menos dominante foi Ischnura (6%). Pantala flavescens (Fabricius, 1798) foi a espécie de odonato mais abundante na área de estudo, registrada em todos os habitats pesquisados. O Índice de Diversidade de Shannon (H) foi de 2,988, e o Índice de Diversidade de Simpson (D) foi de 0,95 para a fauna de odonatos coletados. A maior abundância de Odonata foi registrada em agosto, setembro e maio, enquanto nenhuma espécie de Odonata foi registrada em janeiro, fevereiro, novembro e dezembro. Corpos dágua lóticos foram os habitats mais adequados, com abundante fauna de odonatos. Anax imaculifrons (Rambur, 1842) foi a espécie de odonato de maior tamanho, com envergadura de 53,2 ± 1,63 mm e comprimento do corpo de 56,3 ± 0,4 mm. O presente estudo mostrou o status da fauna de odonatos de Swat, Paquistão, em diversos habitats e variação sazonal ao longo do ano. Recomenda-se trabalho adicional para preencher as lacunas na literatura existente.

Diversity of the Anisoptera & Zygoptera (Odonata: Insecta) of Swat, Pakistan / Diversidade de Anisoptera e Zygoptera (Odonata: Insecta) de Swat, Paquistão

Odonates are important biological control agents for the control of insect pests and insect disease vectors of medical and veterinary importance. The present study was conducted to evaluate the odonate fauna of Swat, Pakistan from March to October 2019. A total of 200 specimens of odonates were collected from diverse habitats. The collected specimens of the order Odonata belonged to 5 families, three families of suborder Anisoptera namely Libellulidae, Gomphidae and Aeshnidae while two families of suborder Zygoptera (Chlorocyphidae and Coenagrionidae). The specimens were categorized into 12 genera and 22 species. Libellulidae was the dominant family (n = 138) accounting for 69% of the odonate fauna. Orthetrum was the dominant genus (n = 73) of suborder Anisoptera accounting for 36.5% of the odonate fauna. The least dominant genera were Anax, Paragomphus and Rhyothemis (n = 5 each) accounting each for 2.5% of the odonate fauna. In Zygoptera, the dominant genus was Ceriagrion (12.5%) and the least dominant genus was Ischnura (6%). Pantala flavescens (Fabricius, 1798) was the most abundant odonate species in the study area recorded from all surveyed habitats. Shannon Diversity Index (H) was 2.988 and Simpson Diversity Index (D) was 0.95 for the collected odonate fauna. The highest abundance of Odonata was recorded in August, September and May while no odonate species were recorded in January, February, November and December. Lotic water bodies were the most suitable habitats with abundant odonate fauna. Anax immaculifrons (Rambur, 1842) was the largest sized odonate species having a wingspan of 53.2±1.63 mm and body length of 56.3 ± 0.4 mm. The present study shows the status of odonate fauna of Swat, Pakistan in diverse habitats and seasonsonal variation throughout the year. Further work is recommended to bridge the gaps in the existing literature.

Odonatos são importantes agentes de controle biológico para o controle de insetos-praga e vetores de doenças de insetos de importância médica e veterinária. O presente estudo foi conduzido para avaliar a fauna de odonatos de Swat, Paquistão, de março a outubro de 2019. Um total de 200 espécimes de odonatos foi coletado em diversos habitats. Os espécimes coletados da ordem Odonata pertenciam a cinco famílias, três famílias da subordem Anisoptera, a saber, Libellulidae, Gomphidae e Aeshnidae, enquanto duas famílias eram da subordem Zygoptera (Chlorocyphidae e Coenagrionidae). Os espécimes foram classificados em 12 gêneros e 22 espécies. Libellulidae foi a família dominante (n = 138), respondendo por 69% da fauna de odonatos. Orthetrum foi o gênero dominante (n = 73) da subordem Anisoptera, responsável por 36,5% da fauna de odonatos. Os gêneros menos dominantes foram Anax, Paragomphus e Rhyothemis (n = 5 cada), representando cada um 2,5% da fauna de odonatos. Em Zygoptera, o gênero dominante foi Ceriagrion (12,5%), e o gênero menos dominante foi Ischnura (6%). Pantala flavescens (Fabricius, 1798) foi a espécie de odonato mais abundante na área de estudo, registrada em todos os habitats pesquisados. O Índice de Diversidade de Shannon (H) foi de 2,988, e o Índice de Diversidade de Simpson (D) foi de 0,95 para a fauna de odonatos coletados. A maior abundância de Odonata foi registrada em agosto, setembro e maio, enquanto nenhuma espécie de Odonata foi registrada em janeiro, fevereiro, novembro e dezembro. Corpos d’água lóticos foram os habitats mais adequados, com abundante fauna de odonatos. Anax imaculifrons (Rambur, 1842) foi a espécie de odonato de maior tamanho, com envergadura de 53,2 ± 1,63 mm e comprimento do corpo de 56,3 ± 0,4 mm. O presente estudo mostrou o status da fauna de odonatos de Swat, Paquistão, em diversos habitats e variação sazonal ao longo do ano. Recomenda-se trabalho adicional para preencher as lacunas na literatura existente.

Diversity of the Anisoptera & Zygoptera (Odonata: Insecta) of Swat, Pakistan / Diversidade de Anisoptera e Zygoptera (Odonata: Insecta) de Swat, Paquistão

Abstract Odonates are important biological control agents for the control of insect pests and insect disease vectors of medical and veterinary importance. The present study was conducted to evaluate the odonate fauna of Swat, Pakistan from March to October 2019. A total of 200 specimens of odonates were collected from diverse habitats. The collected specimens of the order Odonata belonged to 5 families, three families of suborder Anisoptera namely Libellulidae, Gomphidae and Aeshnidae while two families of suborder Zygoptera (Chlorocyphidae and Coenagrionidae). The specimens were categorized into 12 genera and 22 species. Libellulidae was the dominant family (n = 138) accounting for 69% of the odonate fauna. Orthetrum was the dominant genus (n = 73) of suborder Anisoptera accounting for 36.5% of the odonate fauna. The least dominant genera were Anax, Paragomphus and Rhyothemis (n = 5 each) accounting each for 2.5% of the odonate fauna. In Zygoptera, the dominant genus was Ceriagrion (12.5%) and the least dominant genus was Ischnura (6%). Pantala flavescens (Fabricius, 1798) was the most abundant odonate species in the study area recorded from all surveyed habitats. Shannon Diversity Index (H) was 2.988 and Simpson Diversity Index (D) was 0.95 for the collected odonate fauna. The highest abundance of Odonata was recorded in August, September and May while no odonate species were recorded in January, February, November and December. Lotic water bodies were the most suitable habitats with abundant odonate fauna. Anax immaculifrons (Rambur, 1842) was the largest sized odonate species having a wingspan of 53.2±1.63 mm and body length of 56.3 ± 0.4 mm. The present study shows the status of odonate fauna of Swat, Pakistan in diverse habitats and seasonsonal variation throughout the year. Further work is recommended to bridge the gaps in the existing literature.

Resumo Odonatos são importantes agentes de controle biológico para o controle de insetos-praga e vetores de doenças de insetos de importância médica e veterinária. O presente estudo foi conduzido para avaliar a fauna de odonatos de Swat, Paquistão, de março a outubro de 2019. Um total de 200 espécimes de odonatos foi coletado em diversos habitats. Os espécimes coletados da ordem Odonata pertenciam a cinco famílias, três famílias da subordem Anisoptera, a saber, Libellulidae, Gomphidae e Aeshnidae, enquanto duas famílias eram da subordem Zygoptera (Chlorocyphidae e Coenagrionidae). Os espécimes foram classificados em 12 gêneros e 22 espécies. Libellulidae foi a família dominante (n = 138), respondendo por 69% da fauna de odonatos. Orthetrum foi o gênero dominante (n = 73) da subordem Anisoptera, responsável por 36,5% da fauna de odonatos. Os gêneros menos dominantes foram Anax, Paragomphus e Rhyothemis (n = 5 cada), representando cada um 2,5% da fauna de odonatos. Em Zygoptera, o gênero dominante foi Ceriagrion (12,5%), e o gênero menos dominante foi Ischnura (6%). Pantala flavescens (Fabricius, 1798) foi a espécie de odonato mais abundante na área de estudo, registrada em todos os habitats pesquisados. O Índice de Diversidade de Shannon (H) foi de 2,988, e o Índice de Diversidade de Simpson (D) foi de 0,95 para a fauna de odonatos coletados. A maior abundância de Odonata foi registrada em agosto, setembro e maio, enquanto nenhuma espécie de Odonata foi registrada em janeiro, fevereiro, novembro e dezembro. Corpos d'água lóticos foram os habitats mais adequados, com abundante fauna de odonatos. Anax imaculifrons (Rambur, 1842) foi a espécie de odonato de maior tamanho, com envergadura de 53,2 ± 1,63 mm e comprimento do corpo de 56,3 ± 0,4 mm. O presente estudo mostrou o status da fauna de odonatos de Swat, Paquistão, em diversos habitats e variação sazonal ao longo do ano. Recomenda-se trabalho adicional para preencher as lacunas na literatura existente.

Diversity of the Anisoptera & Zygoptera (Odonata: Insecta) of Swat, Pakistan / Diversidade de Anisoptera e Zygoptera (Odonata: Insecta) de Swat, Paquistão

Odonates are important biological control agents for the control of insect pests and insect disease vectors of medical and veterinary importance. The present study was conducted to evaluate the odonate fauna of Swat, Pakistan from March to October 2019. A total of 200 specimens of odonates were collected from diverse habitats. The collected specimens of the order Odonata belonged to 5 families, three families of suborder Anisoptera namely Libellulidae, Gomphidae and Aeshnidae while two families of suborder Zygoptera (Chlorocyphidae and Coenagrionidae). The specimens were categorized into 12 genera and 22 species. Libellulidae was the dominant family (n = 138) accounting for 69% of the odonate fauna. Orthetrum was the dominant genus (n = 73) of suborder Anisoptera accounting for 36.5% of the odonate fauna. The least dominant genera were Anax, Paragomphus and Rhyothemis (n = 5 each) accounting each for 2.5% of the odonate fauna. In Zygoptera, the dominant genus was Ceriagrion (12.5%) and the least dominant genus was Ischnura (6%). Pantala flavescens (Fabricius, 1798) was the most abundant odonate species in the study area recorded from all surveyed habitats. Shannon Diversity Index (H) was 2.988 and Simpson Diversity Index (D) was 0.95 for the collected odonate fauna. The highest abundance of Odonata was recorded in August, September and May while no odonate species were recorded in January, February, November and December. Lotic water bodies were the most suitable habitats with abundant odonate fauna. Anax immaculifrons (Rambur, 1842) was the largest sized odonate species having a wingspan of 53.2±1.63 mm and body length of 56.3 ± 0.4 mm. The present study shows the status of odonate fauna of Swat, Pakistan in diverse habitats and seasonsonal variation throughout the year. Further work is recommended to bridge the gaps in the existing literature.(AU)

Odonatos são importantes agentes de controle biológico para o controle de insetos-praga e vetores de doenças de insetos de importância médica e veterinária. O presente estudo foi conduzido para avaliar a fauna de odonatos de Swat, Paquistão, de março a outubro de 2019. Um total de 200 espécimes de odonatos foi coletado em diversos habitats. Os espécimes coletados da ordem Odonata pertenciam a cinco famílias, três famílias da subordem Anisoptera, a saber, Libellulidae, Gomphidae e Aeshnidae, enquanto duas famílias eram da subordem Zygoptera (Chlorocyphidae e Coenagrionidae). Os espécimes foram classificados em 12 gêneros e 22 espécies. Libellulidae foi a família dominante (n = 138), respondendo por 69% da fauna de odonatos. Orthetrum foi o gênero dominante (n = 73) da subordem Anisoptera, responsável por 36,5% da fauna de odonatos. Os gêneros menos dominantes foram Anax, Paragomphus e Rhyothemis (n = 5 cada), representando cada um 2,5% da fauna de odonatos. Em Zygoptera, o gênero dominante foi Ceriagrion (12,5%), e o gênero menos dominante foi Ischnura (6%). Pantala flavescens (Fabricius, 1798) foi a espécie de odonato mais abundante na área de estudo, registrada em todos os habitats pesquisados. O Índice de Diversidade de Shannon (H) foi de 2,988, e o Índice de Diversidade de Simpson (D) foi de 0,95 para a fauna de odonatos coletados. A maior abundância de Odonata foi registrada em agosto, setembro e maio, enquanto nenhuma espécie de Odonata foi registrada em janeiro, fevereiro, novembro e dezembro. Corpos dágua lóticos foram os habitats mais adequados, com abundante fauna de odonatos. Anax imaculifrons (Rambur, 1842) foi a espécie de odonato de maior tamanho, com envergadura de 53,2 ± 1,63 mm e comprimento do corpo de 56,3 ± 0,4 mm. O presente estudo mostrou o status da fauna de odonatos de Swat, Paquistão, em diversos habitats e variação sazonal ao longo do ano. Recomenda-se trabalho adicional para preencher as lacunas na literatura existente.(AU)

Odonate Communities of the Sucupira Reservoir, Rio Uberabinha, Minas Gerais, Brazil

Dragonflies and damselflies (Insecta: Odonata) are widely distributed among freshwater ecosystems of tropical and temperate environments. They are also particularly sensitive to anthropogenic changes. The objective of this study was to inventory the odonate fauna of a section of the Sucupira Reservoir on Rio Uberabinha, Uberlândia, Minas Gerais, Brazil, and to document the species composition of the odonate fauna during the dry and rainy seasons. The study also aimed to describe the distribution of the sampled species in Brazilian states. Sampling took place in August and September of 2017 (dry season) and in February and March of 2018 (rainy season), and recorded 860 individuals of 43 species belonging to 26 genera and six families. Six new records representing the families Gomphidae, Libellulidae and Coenagrionidae were recorded for the state of Minas Gerais. Seventeen species were collected only during the rainy season and eight only during the dry season, while 18 species were found in both seasons. The rainy season had greater abundance, with four times as many individuals as the dry season. This study increases the number of records for Odonata in the Minas Gerais state, and reinforces the trend for greater predominance of this group during the rainy season in this biome.

Odonate Communities of the Sucupira Reservoir, Rio Uberabinha, Minas Gerais, Brazil

Dragonflies and damselflies (Insecta: Odonata) are widely distributed among freshwater ecosystems of tropical and temperate environments. They are also particularly sensitive to anthropogenic changes. The objective of this study was to inventory the odonate fauna of a section of the Sucupira Reservoir on Rio Uberabinha, Uberlândia, Minas Gerais, Brazil, and to document the species composition of the odonate fauna during the dry and rainy seasons. The study also aimed to describe the distribution of the sampled species in Brazilian states. Sampling took place in August and September of 2017 (dry season) and in February and March of 2018 (rainy season), and recorded 860 individuals of 43 species belonging to 26 genera and six families. Six new records representing the families Gomphidae, Libellulidae and Coenagrionidae were recorded for the state of Minas Gerais. Seventeen species were collected only during the rainy season and eight only during the dry season, while 18 species were found in both seasons. The rainy season had greater abundance, with four times as many individuals as the dry season. This study increases the number of records for Odonata in the Minas Gerais state, and reinforces the trend for greater predominance of this group during the rainy season in this biome.(AU)

Libélulas (Odonata) predadas por moscas-assassinas (Diptera: Asilidae) no estado de Minas Gerais, sudeste do Brasil / Dragonflies (Odonata) preyed by robber flies (Diptera: Asilidae) in the state of Minas Gerais, southeasternBrazil

Os insetos da ordem Odonata são importantes nos ecossistemas aquáticos, atuando como predadores e algumas vezes como presas, sendo predados por aves, peixes e também outros insetos, tendo como exemplo as moscas-assassinas da família Asilidae. Entretanto, registros dessa interação são escassos no Brasil, sendo o objetivo desse relato, notificar a ocorrência de predação das espécies de odonata Hetaerina longipes Selys, 1853 (Calopterygidae) e de Argia claussenii Selys, 1865 (Coenagrionidae) por Archilestris capnoptera (Wiedemann, 1828). Os registros foram realizados ao acaso no Parque Estadual Serra do Papagaio e no Parque Estadual do Ibitipoca, nos anos de 2015 e 2017. A predação pode ser reflexo da frequência das espécies de odonatos na época dos registros, pois os asilídeos são predadores oportunistas e generalistas, porém, novos estudos são necessários para avaliar os impactos da predação nas populações de libélulas.

Insects of the Odonata order are important in aquatic ecosystems, acting sometimes as predatorsand sometimes as prey to birds, fish and other insects, such as the robber flies of the Asilidae family.However, records of this interaction are scarce for Brazil. The purpose of this report is notify the occurrence ofpredation of the odonata species Hetaerina longipes Selys, 1853 (Calopterygidae) and Argia claussenii Selys,1865 (Coenagrionidae) by Archilestris capnoptera (Wiedemann, 1828). The records were occasionally made atthe Parque Estadual Serra do Papagaio and at the Parque Estadual do Ibitipoca, in the years 2015 and 2017.Predation may be a reflection of the frequency of odonate species at the time of the registrations, because theasilids are opportunistic and generalist predators. New studies are however needed to assess the impacts ofpredation on dragonfly populations.

Libélulas (Odonata) predadas por moscas-assassinas (Diptera: Asilidae) no estado de Minas Gerais, sudeste do Brasil / Dragonflies (Odonata) preyed by robber flies (Diptera: Asilidae) in the state of Minas Gerais, southeasternBrazil

Os insetos da ordem Odonata são importantes nos ecossistemas aquáticos, atuando como predadores e algumas vezes como presas, sendo predados por aves, peixes e também outros insetos, tendo como exemplo as moscas-assassinas da família Asilidae. Entretanto, registros dessa interação são escassos no Brasil, sendo o objetivo desse relato, notificar a ocorrência de predação das espécies de odonata Hetaerina longipes Selys, 1853 (Calopterygidae) e de Argia claussenii Selys, 1865 (Coenagrionidae) por Archilestris capnoptera (Wiedemann, 1828). Os registros foram realizados ao acaso no Parque Estadual Serra do Papagaio e no Parque Estadual do Ibitipoca, nos anos de 2015 e 2017. A predação pode ser reflexo da frequência das espécies de odonatos na época dos registros, pois os asilídeos são predadores oportunistas e generalistas, porém, novos estudos são necessários para avaliar os impactos da predação nas populações de libélulas.(AU)

Insects of the Odonata order are important in aquatic ecosystems, acting sometimes as predatorsand sometimes as prey to birds, fish and other insects, such as the robber flies of the Asilidae family.However, records of this interaction are scarce for Brazil. The purpose of this report is notify the occurrence ofpredation of the odonata species Hetaerina longipes Selys, 1853 (Calopterygidae) and Argia claussenii Selys,1865 (Coenagrionidae) by Archilestris capnoptera (Wiedemann, 1828). The records were occasionally made atthe Parque Estadual Serra do Papagaio and at the Parque Estadual do Ibitipoca, in the years 2015 and 2017.Predation may be a reflection of the frequency of odonate species at the time of the registrations, because theasilids are opportunistic and generalist predators. New studies are however needed to assess the impacts ofpredation on dragonfly populations.(AU)

A new species of Ischnura (Odonata: Coenagrionidae) from high altitude eastern Andes, of Colombia

Ischnura mahechai sp. nov. is described and illustrated based on specimens collected at the Eastern Andean mountain range of Colômbia. The species is close to Ischnura cruzi De Marmels, 1987 but differs from it by the structure of male anal appendages and female hind prothoracic lobe. The specimens were collected on a small Andine lake at 3,600 m, the 4th altitudinal record for a resident odonate.

A new species of Ischnura (Odonata: Coenagrionidae) from high altitude eastern Andes, of Colombia

Ischnura mahechai sp. nov. is described and illustrated based on specimens collected at the Eastern Andean mountain range of Colômbia. The species is close to Ischnura cruzi De Marmels, 1987 but differs from it by the structure of male anal appendages and female hind prothoracic lobe. The specimens were collected on a small Andine lake at 3,600 m, the 4th altitudinal record for a resident odonate.

A new species of Ischnura (Odonata: Coenagrionidae) from high altitude eastern Andes, of Colombia

Ischnura mahechai sp. nov. is described and illustrated based on specimens collected at the Eastern Andean mountain range of Colômbia. The species is close to Ischnura cruzi De Marmels, 1987 but differs from it by the structure of male anal appendages and female hind prothoracic lobe. The specimens were collected on a small Andine lake at 3,600 m, the 4th altitudinal record for a resident odonate.

Predation of Piaractus mesopotamicus and Oreochromis niloticus larvae by Pantala flavescens with different length classes - doi: 10.4025/actascibiolsci.v33i4.5470 / Predation of Piaractus mesopotamicus and Oreochromis niloticus larvae by Pantala flavescens with different length classes - doi: 10.4025/actascibiolsci.v33i4.5470

The experiment had as objective to study the survival of Piaractus mesopotamicus and Oreochromis niloticus larvae subject to predation by Pantala flavescens larvae with different length classes. We used 120 larvae of P. mesopotamicus, 120 of O. niloticus, and also 24 larvae of Pantala flavescens, distributed in 24 aquariums with useful volume for 2 L, being placed one Odonate for aquarium. The treatments differed as regard to the prey species and the predator size, being kept a control treatment. An aquarium (2 L) containing one larvae of Odonate and 10 larvae of fish were considered an experimental unit. After the beginning, each three hours (18:00, 21:00, 0:00, 3:00, 6:00, 9:00, 12:00, 15:00 and 18:00h), the remnant larvae of fish (alive) in each experimental unit was quantified, and we replaced the consumed larvae, so that we always had 10 larvae of fish at each aquarium after each counting. For both fish species, there was a slight increase in consumption by the Odonate with intermediate size, but the values did not differ statistically (p > 0.05). Larvae of Odonate in the treatments with greater length presented a lower consumption (p 0.05) than in other treatments.

The experiment had as objective to study the survival of Piaractus mesopotamicus and Oreochromis niloticus larvae subject to predation by Pantala flavescens larvae with different length classes. We used 120 larvae of P. mesopotamicus, 120 of O. niloticus, and also 24 larvae of Pantala flavescens, distributed in 24 aquariums with useful volume for 2 L, being placed one Odonate for aquarium. The treatments differed as regard to the prey species and the predator size, being kept a control treatment. An aquarium (2 L) containing one larvae of Odonate and 10 larvae of fish were considered an experimental unit. After the beginning, each three hours (18:00, 21:00, 0:00, 3:00, 6:00, 9:00, 12:00, 15:00 and 18:00h), the remnant larvae of fish (alive) in each experimental unit was quantified, and we replaced the consumed larvae, so that we always had 10 larvae of fish at each aquarium after each counting. For both fish species, there was a slight increase in consumption by the Odonate with intermediate size, but the values did not differ statistically (p > 0.05). Larvae of Odonate in the treatments with greater length presented a lower consumption (p 0.05) than in other treatments.

Predation of Piaractus mesopotamicus and Oreochromis niloticus larvae by Pantala flavescens with different length classes / Predação de P. mesopotamicus e O. niloticus por larvas de Pantala flavescens de diferentes classes de coprimento

The experiment had as objective to study the survival of Piaractus mesopotamicus and Oreochromis niloticus larvae subject to predation by Pantala flavescens larvae with different length classes. We used 120 larvae of P. mesopotamicus, 120 of O. niloticus, and also 24 larvae of Pantala flavescens, distributed in 24 aquariums with useful volume for 2 L, being placed one Odonate for aquarium. The treatments differed as regard to the prey species and the predator size, being kept a control treatment. An aquarium (2 L) containing one larvae of Odonate and 10 larvae of fish were considered an experimental unit. After the beginning, each three hours (18:00, 21:00, 0:00, 3:00, 6:00, 9:00, 12:00, 15:00 and 18:00h), the remnant larvae of fish (alive) in each experimental unit was quantified, and we replaced the consumed larvae, so that we always had 10 larvae of fish at each aquarium after each counting. For both fish species, there was a slight increase in consumption by the Odonate with intermediate size, but the values did not differ statistically (p > 0.05). Larvae of Odonate in the treatments with greater length presented a lower consumption (p < 0.05) than in other treatments.

O experimento teve como objetivo avaliar a sobrevivência de larvas de P. mesopotamicus e O. niloticus submetidas à predação por larvas de Pantala flavescens de diferentes classes de comprimento. Foram utilizadas 120 larvas de cada espécie de peixe e 24 larvas de Odonata, distribuídas em 24 aquários (2 L), sendo colocada uma Odonata por aquário. Os tratamentos diferiram quanto à espécie de presa e o tamanho do predador, sendo mantido um tratamento-controle. Um aquário (2 L) com uma Odonata e dez larvas de peixe foi considerada uma unidade experimental. As Odonatas foram colocadas nos aquários 1h antes das larvas de peixe. Foram efetuadas contagens a cada 3h (18, 21, 0, 3, 6, 9, 12, 15 e 18h) das larvas de peixe remanescentes (vivas) em cada unidade experimental, sendo repostas as larvas consumidas, de modo a ter dez larvas de peixe em cada aquário logo após cada contagem. Para ambas as espécies de peixe, foi observado leve aumento no consumo das larvas pelas Odonatas de tamanho intermediário, porém os valores não diferiram estatisticamente (p > 0,05). As larvas de Odonata nos tratamentos em que apresentavam maior comprimento tiveram consumo menor (p < 0,05) que nos demais.

Influence of aquatic plants on the predation of Piaractusmesopotamicus larvae by Pantala flavescens / Influência de macrófitas aquáticas na predação de larvas de Piaractus mesopotamicus por Pantala flavescens

The experiment aimed to study the influence of the aquatic plants E. najas,P. stratiotes and S. auriculata on the predation of P. mesopotamicus larvae by P. flavescens. Onehundred and twenty larvae of P. mesopotamicus and 24 larvae of P. flavescens were placed in 24aquariums with capacity of 12 L, with one Odonate per aquarium. Treatments weredifferent regarding the species of aquatic plants E. najas, S. auriculata and P. stratiotes, withone control treatment without aquatic plants. One aquarium (12 L) containing oneOdonate and 30 P. mesopotamicus larvae was considered one experimental unit. After 18hours, the Odonates were removed from the aquariums and fish larvae left (alive) werecounted in each experimental unit. The survival rate of P. mesopotamicus larvae in thetreatment without aquatic plants (control) was significantly lower than in the treatmentwith E. najas. However, the survival rates in the aquariums with floating aquatic plants didnot differ from the control. The morphological characteristics of E. najas promoted higherstructural complexity in the environment, offering more protection to the fish larvae, andincreasing their survival. We concluded that the presence of the submerged aquatic plant E.najas promoted the reduction of predation of P. mesopotamicus larvae by Pantala flavescens.

O experimento teve como objetivo estudar ainfluência de macrófitas aquáticas na predação de larvas de peixe P. mesopotamicus por larvasde P. flavescens Foram utilizadas 720 larvas de P. mesopotamicus e 24 larvas de P. flavescens,distribuídas em 24 aquários com volume útil para 12 L, sendo colocada uma larva deOdonata por aquário. Os tratamentos diferiram quanto à espécie de macrófita E. najas (E),S. auriculata (S) e P. stratiotes (P) sendo mantido um tratamento controle (C) sem macrófitas.Um aquário contendo uma larva de Odonata e 30 larvas de P. mesopotamicus foi consideradouma unidade experimental. Após 18 horas do início do experimento, as Odonatas foramretiradas dos aquários e foi realizada a contagem das larvas de peixe remanescentes (vivas)em cada unidade experimental. A taxa de sobrevivência das larvas de P. mesopotamicus notratamento sem macrófita (controle) foi significativamente menor quando comparada aotratamento contendo a macrófita submersa E. najas. Entretanto o valor de sobrevivência nosaquários com macrófitas flutuantes não diferiu do controle. As características morfológicasda E. najas promoveram uma maior complexidade estrutural no ambiente, gerando ummaior numero de abrigos para as larvas de peixe, aumentando assim a sobrevivência dasmesmas. Conclui-se que a presença da macrófita aquática E. najas promove redução napredação das larvas de P. mesopotamicus por larvas de P. flavescens.

Influence of aquatic plants on the predation of Piaractusmesopotamicus larvae by Pantala flavescens / Influência de macrófitas aquáticas na predação de larvas de Piaractus mesopotamicus por Pantala flavescens

The experiment aimed to study the influence of the aquatic plants E. najas,P. stratiotes and S. auriculata on the predation of P. mesopotamicus larvae by P. flavescens. Onehundred and twenty larvae of P. mesopotamicus and 24 larvae of P. flavescens were placed in 24aquariums with capacity of 12 L, with one Odonate per aquarium. Treatments weredifferent regarding the species of aquatic plants E. najas, S. auriculata and P. stratiotes, withone control treatment without aquatic plants. One aquarium (12 L) containing oneOdonate and 30 P. mesopotamicus larvae was considered one experimental unit. After 18hours, the Odonates were removed from the aquariums and fish larvae left (alive) werecounted in each experimental unit. The survival rate of P. mesopotamicus larvae in thetreatment without aquatic plants (control) was significantly lower than in the treatmentwith E. najas. However, the survival rates in the aquariums with floating aquatic plants didnot differ from the control. The morphological characteristics of E. najas promoted higherstructural complexity in the environment, offering more protection to the fish larvae, andincreasing their survival. We concluded that the presence of the submerged aquatic plant E.najas promoted the reduction of predation of P. mesopotamicus larvae by Pantala flavescens.(AU)

O experimento teve como objetivo estudar ainfluência de macrófitas aquáticas na predação de larvas de peixe P. mesopotamicus por larvasde P. flavescens Foram utilizadas 720 larvas de P. mesopotamicus e 24 larvas de P. flavescens,distribuídas em 24 aquários com volume útil para 12 L, sendo colocada uma larva deOdonata por aquário. Os tratamentos diferiram quanto à espécie de macrófita E. najas (E),S. auriculata (S) e P. stratiotes (P) sendo mantido um tratamento controle (C) sem macrófitas.Um aquário contendo uma larva de Odonata e 30 larvas de P. mesopotamicus foi consideradouma unidade experimental. Após 18 horas do início do experimento, as Odonatas foramretiradas dos aquários e foi realizada a contagem das larvas de peixe remanescentes (vivas)em cada unidade experimental. A taxa de sobrevivência das larvas de P. mesopotamicus notratamento sem macrófita (controle) foi significativamente menor quando comparada aotratamento contendo a macrófita submersa E. najas. Entretanto o valor de sobrevivência nosaquários com macrófitas flutuantes não diferiu do controle. As características morfológicasda E. najas promoveram uma maior complexidade estrutural no ambiente, gerando ummaior numero de abrigos para as larvas de peixe, aumentando assim a sobrevivência dasmesmas. Conclui-se que a presença da macrófita aquática E. najas promove redução napredação das larvas de P. mesopotamicus por larvas de P. flavescens.(AU)

Predation of Piaractus mesopotamicus and Oreochromis niloticus larvae by Pantala flavescens with different length classes - doi: 10.4025/actascibiolsci.v33i4.5470 / Predation of Piaractus mesopotamicus and Oreochromis niloticus larvae by Pantala flavescens with different length classes - doi: 10.4025/actascibiolsci.v33i4.5470

The experiment had as objective to study the survival of Piaractus mesopotamicus and Oreochromis niloticus larvae subject to predation by Pantala flavescens larvae with different length classes. We used 120 larvae of P. mesopotamicus, 120 of O. niloticus, and also 24 larvae of Pantala flavescens, distributed in 24 aquariums with useful volume for 2 L, being placed one Odonate for aquarium. The treatments differed as regard to the prey species and the predator size, being kept a control treatment. An aquarium (2 L) containing one larvae of Odonate and 10 larvae of fish were considered an experimental unit. After the beginning, each three hours (18:00, 21:00, 0:00, 3:00, 6:00, 9:00, 12:00, 15:00 and 18:00h), the remnant larvae of fish (alive) in each experimental unit was quantified, and we replaced the consumed larvae, so that we always had 10 larvae of fish at each aquarium after each counting. For both fish species, there was a slight increase in consumption by the Odonate with intermediate size, but the values did not differ statistically (p > 0.05). Larvae of Odonate in the treatments with greater length presented a lower consumption (p 0.05) than in other treatments.

The experiment had as objective to study the survival of Piaractus mesopotamicus and Oreochromis niloticus larvae subject to predation by Pantala flavescens larvae with different length classes. We used 120 larvae of P. mesopotamicus, 120 of O. niloticus, and also 24 larvae of Pantala flavescens, distributed in 24 aquariums with useful volume for 2 L, being placed one Odonate for aquarium. The treatments differed as regard to the prey species and the predator size, being kept a control treatment. An aquarium (2 L) containing one larvae of Odonate and 10 larvae of fish were considered an experimental unit. After the beginning, each three hours (18:00, 21:00, 0:00, 3:00, 6:00, 9:00, 12:00, 15:00 and 18:00h), the remnant larvae of fish (alive) in each experimental unit was quantified, and we replaced the consumed larvae, so that we always had 10 larvae of fish at each aquarium after each counting. For both fish species, there was a slight increase in consumption by the Odonate with intermediate size, but the values did not differ statistically (p > 0.05). Larvae of Odonate in the treatments with greater length presented a lower consumption (p 0.05) than in other treatments.