Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 20 de 57
Filtrer
Plus de filtres











Gamme d'année
1.
Bull Entomol Res ; 110(5): 638-644, 2020 Oct.
Article de Anglais | MEDLINE | ID: mdl-32381143

RÉSUMÉ

Telenomus podisi Ashmead (Hymenoptera: Scelionidae) is the most important egg parasitoid of Euschistus heros (Fabricius) (Hemiptera: Pentatomidae), and its successful parasitism is related to their searching ability to find suitable hosts under a complex chemical environment using host-reliable cues. Thus, the objective of this study was to elucidate chemical substances on the external layer of E. heros eggs and report its potential kairomonal activity on T. podisi. We tested female wasps in olfactometer system to synthetic compounds obtained from a chemical identification of E. heros egg masses. The synthetic blend was also evaluated in parasitism tests under laboratory and semi-field conditions. We identified 31 substances from egg surface extracts, including monoterpenes, aldehydes and alkanes. Among those compounds, a synthetic solution including camphene, ß-pinene, limonene and benzaldehyde-induced chemotaxic behaviour on the wasps and increased the parasitism on E. heros eggs, either in laboratory or semi-field test, suggesting its potential use to T. podisi manipulation and parasitism improvement.


Sujet(s)
Heteroptera/composition chimique , Ovule/composition chimique , Phéromones/pharmacologie , Guêpes/effets des médicaments et des substances chimiques , Animaux , Comportement animal/effets des médicaments et des substances chimiques , Femelle , Heteroptera/parasitologie , Ovule/parasitologie
2.
Neotrop Entomol ; 48(6): 983-991, 2019 Dec.
Article de Anglais | MEDLINE | ID: mdl-31823153

RÉSUMÉ

Aphidius colemani (Viereck) was reported in Brazil before the Biological Control Program of Wheat Aphids (BCPWA) when Mediterranean genotypes were introduced from France and Israel. This species was re-described as a complex called A. colemani group composed of three species. Consequently, uncertainty remains about which parasitoid of the group is occurring in southern Brazil. This study has two main objectives: (i) re-examine the species status of A. colemani group collected during the introduction of parasitoids and from a 10-year (2009-2018) monitoring program in wheat fields in northern Rio Grande do Sul (RS), Brazil; (ii) describe the variation in the population density of parasitoids and its association with meteorological factors during this period. We examined 116 specimens from the Embrapa Wheat entomological collection, and those collected in Moericke traps in Coxilha, RS. All the parasitoids of the A. colemani group from the BCPWA period were identified as Aphidius platensis (Brèthes). In traps, 6541 cereal aphid parasitoids were collected, of which 61.9% (n = 4047) were from A. colemani group and all those were identified as A. platensis. Temperature was the factor that effected population density with the highest number of parasitoids recorded in the winter months. Sex ratio changed between years varying from 0.50 to 0.97. The parasitoid A. platensis was the only species in the A. colemani group sampled during 10 years of monitoring.


Sujet(s)
Aphides/parasitologie , Agents de lutte biologique , Guêpes/classification , Guêpes/croissance et développement , Animaux , Brésil , Femelle , Mâle , Lutte biologique contre les nuisibles , Densité de population , Saisons , Sexe-ratio , Température , Triticum , Guêpes/anatomie et histologie , Ailes d'animaux/anatomie et histologie
3.
Neotrop Entomol ; 47(5): 689-697, 2018 Oct.
Article de Anglais | MEDLINE | ID: mdl-29679311

RÉSUMÉ

Parasitoid host selection is mainly mediated by chemical cues, which can be adjusted by experience, changing their innate behavior. Therefore, this study evaluated if immature experience (pre-imaginal conditioning) on eggs and volatiles from different host eggs has influence on parasitism and chemotaxic behavior of Telenomus podisi Ashmead and/or Trissolcus basalis Wollaston (Hymenoptera: Scelionidae). Both wasp species were submitted to a multiple-choice parasitism test among Euschistus heros (Fabricius), Piezodorus guildinii (Westwood), and Nezara viridula L. (Hemiptera: Pentatomidae) (Hemiptera: Pentatomidae) egg masses. Eggs from these three stink bugs were equally offered to female parasitoids. After that, adults which emerged from each host were also exposed to parasitism in a multiple-choice test for up to an additional generation. Moreover, in olfactometer "Y," the behavior of innate and experienced T. podisi females to volatiles from hosts' egg extracts was tested, to study their learning and memory ability. The original host had influence on T. podisi parasitism; however, T. basalis always parasitized more N. viridula eggs independently of its last rearing host. Innate T. podisi females responded positively to E. heros and P. guildinii egg volatiles, but this behavior was not observed in N. viridula. When T. podisi females were experienced on egg volatiles from a new host, they showed significant learning and memory ability for the specific host volatile for, at least, 24 h. Experienced wasps responded positively to N. viridula and through this result we have evidences about the possibility to manipulate wasp's preferences to a specific target host.


Sujet(s)
Heteroptera/parasitologie , Spécificité d'hôte , Interactions hôte-parasite , Guêpes/physiologie , Animaux , Femelle , Apprentissage , Olfactométrie , Ovule/composition chimique , Ovule/parasitologie , Composés organiques volatils/composition chimique
4.
Braz. J. Biol. ; 77(4): 731-744, Nov. 2017. ilus, tab, graf
Article de Anglais | VETINDEX | ID: vti-20391

RÉSUMÉ

Simplified environments characterize agroecosystems, reducing the diversity of associated plants, which are not cultivated for economic purposes, causing unbalances that can promote the emergence of cultivated plants pests, as well as the reduction of their natural enemies. Management systems that increase diversity in agroecosystems can extend the action of natural enemies of pests. Studies to understand the diversity of insects associated with rice cultivation and determine their ecological guilds can provide information about the composition and structure of such ecosystems, which can be applied to integrated pest management. Therefore, the study aimed to describe and compare groups of insects in irrigated rice fields, with organic management using two different systems of levees vegetation management, and relate them to the phenological states of rice cultivation (seedling, vegetative, and reproductive). Samples were taken in a plantation located in Águas Claras district of Viamão, RS. The total area of 18 ha was divided into two. A subarea called not cut (NC), where wild vegetation of levees was maintained, and the subarea named cut (C), where monthly cuts were made to levees vegetation, from the beginning of soil preparation until the harvest. From October 2012 to March 2013 were held weekly collections in quadrats randomly located in both the rice fields and the levees. A total of 800 insects were collected, 429 in the C subarea and 371 in the NC. There were identified 97 morphospecies in the C and 108 in NC, being 54 shared between the subareas. The captured insects were grouped into guilds: saprophages (C = 38.2%; NC = 27.5%), phytophagous (C = 28.5%; NC = 33.2%), entomophagous (grouping parasitoids and predators) (C = 29.4%; NC = 35%) and finally other insects (C = 4 %; NC = 4.3%). The peak abundance of phytophagous and entomophagous was registered in the vegetative stage of rice.(AU)


Os agroecossistemas se caracterizam por ambientes simplificados, com redução da diversidade de plantas associadas, que não são as cultivadas para fins econômicos, causando desequilíbrios que podem levar ao surgimento de insetos nocivos, assim como a diminuição de seus inimigos naturais. Sistemas de manejo que priorizem o aumento da diversidade no agroecossistema podem ampliar a ação de inimigos naturais de pragas. Estudos que busquem entender a diversidade de insetos associados ao cultivo de arroz irrigado, bem como determinar as guildas ou grupos ecológicos aos quais pertencem, podem trazer informações sobre a composição e estrutura dos ecossistemas que possam ser aplicadas no manejo integrado de pragas. Neste sentido, o estudo objetivou conhecer e comparar a diversidade de insetos entre áreas de cultivo orgânico de arroz irrigado, diferenciadas pelo manejo da vegetação das taipas e relacionar com os estádios fenológicos da cultura. As amostragens foram realizadas no distrito de Águas Claras, município de Viamão, RS. A área total de 18 ha foi subdividida em duas. Numa subárea, denominada não roçada (NR) a vegetação espontânea das taipas foi mantida, na outra, roçada (R), foram feitas roçadas mensais das taipas, desde o início do preparo do solo, até a colheita. Entre outubro de 2012 a março de 2013 realizaram-se coletas semanais, em quadrats, situados aleatoriamente tanto nas quadras de arroz quanto nas taipas. Foi coletado um total de 800 insetos, 429 na R e 371 na NR. Foram identificadas 97 morfoespécies na R e 108 na NR, das quais 54 foram compartilhadas entre as subáreas. As guildas registradas foram: saprófagos (R = 38,2%; NR = 27,5%), fitófagos (R = 28,5%; NR = 33,2%), entomófagos (reunindo parasitoides e predadores) (R = 29,4%; NR = 35%) e outros (R = 4%; NR = 4,3%). O pico de abundância de fitófagos e entomófagos foi registrado na fase vegetativa do arroz.(AU)

5.
Braz. j. biol ; Braz. j. biol;77(4): 731-744, Nov. 2017. tab, graf
Article de Anglais | LILACS | ID: biblio-888811

RÉSUMÉ

Abstract Simplified environments characterize agroecosystems, reducing the diversity of associated plants, which are not cultivated for economic purposes, causing unbalances that can promote the emergence of cultivated plants pests, as well as the reduction of their natural enemies. Management systems that increase diversity in agroecosystems can extend the action of natural enemies of pests. Studies to understand the diversity of insects associated with rice cultivation and determine their ecological guilds can provide information about the composition and structure of such ecosystems, which can be applied to integrated pest management. Therefore, the study aimed to describe and compare groups of insects in irrigated rice fields, with organic management using two different systems of levees vegetation management, and relate them to the phenological states of rice cultivation (seedling, vegetative, and reproductive). Samples were taken in a plantation located in Águas Claras district of Viamão, RS. The total area of 18 ha was divided into two. A subarea called not cut (NC), where wild vegetation of levees was maintained, and the subarea named cut (C), where monthly cuts were made to levees vegetation, from the beginning of soil preparation until the harvest. From October 2012 to March 2013 were held weekly collections in quadrats randomly located in both the rice fields and the levees. A total of 800 insects were collected, 429 in the C subarea and 371 in the NC. There were identified 97 morphospecies in the C and 108 in NC, being 54 shared between the subareas. The captured insects were grouped into guilds: saprophages (C = 38.2%; NC = 27.5%), phytophagous (C = 28.5%; NC = 33.2%), entomophagous (grouping parasitoids and predators) (C = 29.4%; NC = 35%) and finally other insects (C = 4 %; NC = 4.3%). The peak abundance of phytophagous and entomophagous was registered in the vegetative stage of rice. At the same stage the UPGMA analysis showed that similarity in species composition was greater than 90% in the groups obtained in the paddy fields of C and NC subareas. The vegetation of levees can positively influence the presence of entomophagous in the field. Although the abundance did not change clearly, the greatest diversity in the NC areas of all the groups, may contribute to the maintenance of ecological services expanding the system resilience.


Resumo Os agroecossistemas se caracterizam por ambientes simplificados, com redução da diversidade de plantas associadas, que não são as cultivadas para fins econômicos, causando desequilíbrios que podem levar ao surgimento de insetos nocivos, assim como a diminuição de seus inimigos naturais. Sistemas de manejo que priorizem o aumento da diversidade no agroecossistema podem ampliar a ação de inimigos naturais de pragas. Estudos que busquem entender a diversidade de insetos associados ao cultivo de arroz irrigado, bem como determinar as guildas ou grupos ecológicos aos quais pertencem, podem trazer informações sobre a composição e estrutura dos ecossistemas que possam ser aplicadas no manejo integrado de pragas. Neste sentido, o estudo objetivou conhecer e comparar a diversidade de insetos entre áreas de cultivo orgânico de arroz irrigado, diferenciadas pelo manejo da vegetação das taipas e relacionar com os estádios fenológicos da cultura. As amostragens foram realizadas no distrito de Águas Claras, município de Viamão, RS. A área total de 18 ha foi subdividida em duas. Numa subárea, denominada não roçada (NR) a vegetação espontânea das taipas foi mantida, na outra, roçada (R), foram feitas roçadas mensais das taipas, desde o início do preparo do solo, até a colheita. Entre outubro de 2012 a março de 2013 realizaram-se coletas semanais, em quadrats, situados aleatoriamente tanto nas quadras de arroz quanto nas taipas. Foi coletado um total de 800 insetos, 429 na R e 371 na NR. Foram identificadas 97 morfoespécies na R e 108 na NR, das quais 54 foram compartilhadas entre as subáreas. As guildas registradas foram: saprófagos (R = 38,2%; NR = 27,5%), fitófagos (R = 28,5%; NR = 33,2%), entomófagos (reunindo parasitoides e predadores) (R = 29,4%; NR = 35%) e outros (R = 4%; NR = 4,3%). O pico de abundância de fitófagos e entomófagos foi registrado na fase vegetativa do arroz. Nesta mesma fase, a análise de UPGMA apontou que a similaridade na composição de espécies foi superior a 90% nos grupos obtidos nas lavouras das subáreas R e NR. A vegetação das taipas pode influenciar positivamente a presença de insetos entomófagos no campo. Embora a abundância não tenha variado significativamente entre as áreas, a maior diversidade na área não roçada em todos os grupos, pode contribuir na manutenção de serviços ecológicos aumentando a resiliência dos sistemas.


Sujet(s)
Animaux , Oryza/croissance et développement , Biodiversité , Agriculture/méthodes , Insectes/physiologie , Brésil , Environnement
6.
Braz J Biol ; 77(4): 731-744, 2017 Nov.
Article de Anglais | MEDLINE | ID: mdl-28355392

RÉSUMÉ

Simplified environments characterize agroecosystems, reducing the diversity of associated plants, which are not cultivated for economic purposes, causing unbalances that can promote the emergence of cultivated plants pests, as well as the reduction of their natural enemies. Management systems that increase diversity in agroecosystems can extend the action of natural enemies of pests. Studies to understand the diversity of insects associated with rice cultivation and determine their ecological guilds can provide information about the composition and structure of such ecosystems, which can be applied to integrated pest management. Therefore, the study aimed to describe and compare groups of insects in irrigated rice fields, with organic management using two different systems of levees vegetation management, and relate them to the phenological states of rice cultivation (seedling, vegetative, and reproductive). Samples were taken in a plantation located in Águas Claras district of Viamão, RS. The total area of 18 ha was divided into two. A subarea called not cut (NC), where wild vegetation of levees was maintained, and the subarea named cut (C), where monthly cuts were made to levees vegetation, from the beginning of soil preparation until the harvest. From October 2012 to March 2013 were held weekly collections in quadrats randomly located in both the rice fields and the levees. A total of 800 insects were collected, 429 in the C subarea and 371 in the NC. There were identified 97 morphospecies in the C and 108 in NC, being 54 shared between the subareas. The captured insects were grouped into guilds: saprophages (C = 38.2%; NC = 27.5%), phytophagous (C = 28.5%; NC = 33.2%), entomophagous (grouping parasitoids and predators) (C = 29.4%; NC = 35%) and finally other insects (C = 4 %; NC = 4.3%). The peak abundance of phytophagous and entomophagous was registered in the vegetative stage of rice. At the same stage the UPGMA analysis showed that similarity in species composition was greater than 90% in the groups obtained in the paddy fields of C and NC subareas. The vegetation of levees can positively influence the presence of entomophagous in the field. Although the abundance did not change clearly, the greatest diversity in the NC areas of all the groups, may contribute to the maintenance of ecological services expanding the system resilience.


Sujet(s)
Agriculture/méthodes , Biodiversité , Insectes/physiologie , Oryza , Animaux , Brésil , Environnement , Oryza/croissance et développement
7.
Braz. j. biol ; 76(3): 774-781, July-Sept. 2016. ilus, graf, tab
Article de Anglais | VETINDEX | ID: vti-25427

RÉSUMÉ

Among the natural enemies of insect pests in rice fields, parasitoids are especially notable. To better understand the space-time dynamics of these insects, the objectives of this study were to describe and compare groups of parasitoids in organic irrigated rice fields using two management approaches for levee vegetation, and to relate them to the phenological stages of rice cultivation (the seedling, vegetative, and reproductive stages). The samples were taken in a plantation located in Viamão, RS, Brazil. The total area of 18 ha was divided into two parts: a no-cut (NC) subarea in which the wild vegetation of the levees was maintained, and a cut (C) subarea in which the levee vegetation was cut monthly. In each subarea, four Malaise traps considered as pseudo-replicas were installed and remained in the field for 24 hours at each sampling location. Collections occurred twice a month from the beginning of cultivation (October 2012) until harvest (March 2013). A total of 3,184 Hymenoptera parasitoids were collected: 2,038 individuals in the NC subarea and 1,146 in the C subarea. We identified 458 morphospecies distributed in 24 families. Mymaridae was the most abundant and Eulophidae was the richest in both subareas. A total of 198 morphospecies was shared between the subareas, including Platygastridae, Eulophidae, and Mymaridae, which were the families with the highest number of shared species. The richness and abundance of parasitoids varied according to their phenological developmental stages, with peak abundance registering during the vegetative period. The Morisita index identified three groupings, indicating a similarity that was related to the three phases of rice growth and development: seedling, vegetative and post-harvest.(AU)


Entre os inimigos naturais de insetos pragas em campos de arroz, parasitoides são especialmente notáveis. Para melhor entender a dinâmica espaço-temporal destes insetos, os objetivos desse estudo foram descrever e comparar os grupos de parasitoides em campos de arroz orgânico irrigado utilizando duas abordagens de manejo da vegetação das taipas, e relacioná-los com os estádios fenológicos da cultura (plântula, vegetativo e reprodutivo). As amostragens foram realizadas em uma plantação localizada em Viamão, RS. A área total de 18 ha foi dividida em duas partes: uma subárea não roçada (NR) na qual a vegetação espontânea das taipas foi mantida, e uma roçada (R) subárea em que a vegetação das taipas foi roçada mensalmente. Em cada subárea, quatro armadilhas Malaise consideradas pseudo-réplicas foram instaladas e mantiveram-se no campo durante 24 horas, em cada local de amostragem. As coletas ocorreram duas vezes por mês, desde o início do cultivo (outubro de 2012) até a colheita (março de 2013). Um total de 3.184 himenópteros parasitoides foram coletados: 2.038 indivíduos na subárea NR e 1.146 na R. Foram identificadas 458 morfoespécies, distribuídas em 24 famílias. Mymaridae foi a mais abundante e Eulophidae a mais rica para ambas as subáreas. Um total de 198 morfoespécies foi compartilhado entre as subáreas, incluindo Platygastridae, Eulophidae e Mymaridae, que foram as famílias com o maior número de espécies compartilhadas. A riqueza e a abundância de parasitoides variou de acordo com as fases de desenvolvimento fenológico da cultura, com pico de abundância registrado no período vegetativo. O Índice de Morisita identificou três grupamentos indicando uma similaridade relacionada às fases da cultura, plântula, vegetativo e, na pós-colheita.(AU)


Sujet(s)
Animaux , Hymenoptera/classification , Irrigation agricole/méthodes , Oryza/croissance et développement
8.
Braz. j. biol ; Braz. j. biol;76(3): 774-781, tab, graf
Article de Anglais | LILACS | ID: lil-785026

RÉSUMÉ

Abstract Among the natural enemies of insect pests in rice fields, parasitoids are especially notable. To better understand the space-time dynamics of these insects, the objectives of this study were to describe and compare groups of parasitoids in organic irrigated rice fields using two management approaches for levee vegetation, and to relate them to the phenological stages of rice cultivation (the seedling, vegetative, and reproductive stages). The samples were taken in a plantation located in Viamão, RS, Brazil. The total area of 18 ha was divided into two parts: a no-cut (NC) subarea in which the wild vegetation of the levees was maintained, and a cut (C) subarea in which the levee vegetation was cut monthly. In each subarea, four Malaise traps considered as pseudo-replicas were installed and remained in the field for 24 hours at each sampling location. Collections occurred twice a month from the beginning of cultivation (October 2012) until harvest (March 2013). A total of 3,184 Hymenoptera parasitoids were collected: 2,038 individuals in the NC subarea and 1,146 in the C subarea. We identified 458 morphospecies distributed in 24 families. Mymaridae was the most abundant and Eulophidae was the richest in both subareas. A total of 198 morphospecies was shared between the subareas, including Platygastridae, Eulophidae, and Mymaridae, which were the families with the highest number of shared species. The richness and abundance of parasitoids varied according to their phenological developmental stages, with peak abundance registering during the vegetative period. The Morisita index identified three groupings, indicating a similarity that was related to the three phases of rice growth and development: seedling, vegetative and post-harvest.


Resumo Entre os inimigos naturais de insetos pragas em campos de arroz, parasitoides são especialmente notáveis. Para melhor entender a dinâmica espaço-temporal destes insetos, os objetivos desse estudo foram descrever e comparar os grupos de parasitoides em campos de arroz orgânico irrigado utilizando duas abordagens de manejo da vegetação das taipas, e relacioná-los com os estádios fenológicos da cultura (plântula, vegetativo e reprodutivo). As amostragens foram realizadas em uma plantação localizada em Viamão, RS. A área total de 18 ha foi dividida em duas partes: uma subárea não roçada (NR) na qual a vegetação espontânea das taipas foi mantida, e uma roçada (R) subárea em que a vegetação das taipas foi roçada mensalmente. Em cada subárea, quatro armadilhas Malaise consideradas pseudo-réplicas foram instaladas e mantiveram-se no campo durante 24 horas, em cada local de amostragem. As coletas ocorreram duas vezes por mês, desde o início do cultivo (outubro de 2012) até a colheita (março de 2013). Um total de 3.184 himenópteros parasitoides foram coletados: 2.038 indivíduos na subárea NR e 1.146 na R. Foram identificadas 458 morfoespécies, distribuídas em 24 famílias. Mymaridae foi a mais abundante e Eulophidae a mais rica para ambas as subáreas. Um total de 198 morfoespécies foi compartilhado entre as subáreas, incluindo Platygastridae, Eulophidae e Mymaridae, que foram as famílias com o maior número de espécies compartilhadas. A riqueza e a abundância de parasitoides variou de acordo com as fases de desenvolvimento fenológico da cultura, com pico de abundância registrado no período vegetativo. O Índice de Morisita identificou três grupamentos indicando uma similaridade relacionada às fases da cultura, plântula, vegetativo e, na pós-colheita.


Sujet(s)
Humains , Animaux , Oryza/croissance et développement , Oryza/parasitologie , Biodiversité , Irrigation agricole , Hymenoptera/physiologie , Brésil , Dynamique des populations , Densité de population , Chaine alimentaire , Biote
9.
Braz J Biol ; 76(3): 774-81, 2016 Apr 19.
Article de Anglais | MEDLINE | ID: mdl-27097090

RÉSUMÉ

Among the natural enemies of insect pests in rice fields, parasitoids are especially notable. To better understand the space-time dynamics of these insects, the objectives of this study were to describe and compare groups of parasitoids in organic irrigated rice fields using two management approaches for levee vegetation, and to relate them to the phenological stages of rice cultivation (the seedling, vegetative, and reproductive stages). The samples were taken in a plantation located in Viamão, RS, Brazil. The total area of 18 ha was divided into two parts: a no-cut (NC) subarea in which the wild vegetation of the levees was maintained, and a cut (C) subarea in which the levee vegetation was cut monthly. In each subarea, four Malaise traps considered as pseudo-replicas were installed and remained in the field for 24 hours at each sampling location. Collections occurred twice a month from the beginning of cultivation (October 2012) until harvest (March 2013). A total of 3,184 Hymenoptera parasitoids were collected: 2,038 individuals in the NC subarea and 1,146 in the C subarea. We identified 458 morphospecies distributed in 24 families. Mymaridae was the most abundant and Eulophidae was the richest in both subareas. A total of 198 morphospecies was shared between the subareas, including Platygastridae, Eulophidae, and Mymaridae, which were the families with the highest number of shared species. The richness and abundance of parasitoids varied according to their phenological developmental stages, with peak abundance registering during the vegetative period. The Morisita index identified three groupings, indicating a similarity that was related to the three phases of rice growth and development: seedling, vegetative and post-harvest.


Sujet(s)
Irrigation agricole , Biodiversité , Hymenoptera/physiologie , Oryza/croissance et développement , Oryza/parasitologie , Animaux , Biote , Brésil , Chaine alimentaire , Humains , Densité de population , Dynamique des populations
10.
Braz. J. Biol. ; 76(3)2016.
Article de Anglais | VETINDEX | ID: vti-744784

RÉSUMÉ

Abstract Among the natural enemies of insect pests in rice fields, parasitoids are especially notable. To better understand the space-time dynamics of these insects, the objectives of this study were to describe and compare groups of parasitoids in organic irrigated rice fields using two management approaches for levee vegetation, and to relate them to the phenological stages of rice cultivation (the seedling, vegetative, and reproductive stages). The samples were taken in a plantation located in Viamão, RS, Brazil. The total area of 18 ha was divided into two parts: a no-cut (NC) subarea in which the wild vegetation of the levees was maintained, and a cut (C) subarea in which the levee vegetation was cut monthly. In each subarea, four Malaise traps considered as pseudo-replicas were installed and remained in the field for 24 hours at each sampling location. Collections occurred twice a month from the beginning of cultivation (October 2012) until harvest (March 2013). A total of 3,184 Hymenoptera parasitoids were collected: 2,038 individuals in the NC subarea and 1,146 in the C subarea. We identified 458 morphospecies distributed in 24 families. Mymaridae was the most abundant and Eulophidae was the richest in both subareas. A total of 198 morphospecies was shared between the subareas, including Platygastridae, Eulophidae, and Mymaridae, which were the families with the highest number of shared species. The richness and abundance of parasitoids varied according to their phenological developmental stages, with peak abundance registering during the vegetative period. The Morisita index identified three groupings, indicating a similarity that was related to the three phases of rice growth and development: seedling, vegetative and post-harvest.


Resumo Entre os inimigos naturais de insetos pragas em campos de arroz, parasitoides são especialmente notáveis. Para melhor entender a dinâmica espaço-temporal destes insetos, os objetivos desse estudo foram descrever e comparar os grupos de parasitoides em campos de arroz orgânico irrigado utilizando duas abordagens de manejo da vegetação das taipas, e relacioná-los com os estádios fenológicos da cultura (plântula, vegetativo e reprodutivo). As amostragens foram realizadas em uma plantação localizada em Viamão, RS. A área total de 18 ha foi dividida em duas partes: uma subárea não roçada (NR) na qual a vegetação espontânea das taipas foi mantida, e uma roçada (R) subárea em que a vegetação das taipas foi roçada mensalmente. Em cada subárea, quatro armadilhas Malaise consideradas pseudo-réplicas foram instaladas e mantiveram-se no campo durante 24 horas, em cada local de amostragem. As coletas ocorreram duas vezes por mês, desde o início do cultivo (outubro de 2012) até a colheita (março de 2013). Um total de 3.184 himenópteros parasitoides foram coletados: 2.038 indivíduos na subárea NR e 1.146 na R. Foram identificadas 458 morfoespécies, distribuídas em 24 famílias. Mymaridae foi a mais abundante e Eulophidae a mais rica para ambas as subáreas. Um total de 198 morfoespécies foi compartilhado entre as subáreas, incluindo Platygastridae, Eulophidae e Mymaridae, que foram as famílias com o maior número de espécies compartilhadas. A riqueza e a abundância de parasitoides variou de acordo com as fases de desenvolvimento fenológico da cultura, com pico de abundância registrado no período vegetativo. O Índice de Morisita identificou três grupamentos indicando uma similaridade relacionada às fases da cultura, plântula, vegetativo e, na pós-colheita.

11.
Neotrop Entomol ; 42(3): 240-5, 2013 Jun.
Article de Anglais | MEDLINE | ID: mdl-23949805

RÉSUMÉ

Tussocks of Andropogon bicornis (Poaceae) make up a significant part of the landscape of the rice-growing region of south Brazil. However, little is known about their role in maintaining insect diversity in anthropized regions. We tested the hypothesis that A. bicornis is a hibernation site for Pentatomoidea (Hemiptera: Heteroptera) by analyzing the composition, structure, and diversity of pentatomoid assemblages over the course of a year. A total of 208 tussocks were removed at fortnightly intervals from April 2010 to March 2011. We collected 3,423 pentatomoid specimens belonging to 22 species distributed in 13 genera of three families, Pentatomidae, Scutelleridae, and Thyreocoridae. The most common species was Tibraca limbativentris Stål, the main rice pest in southern Brazil, followed by Oebalus ypsilongriseus (De Geer) and Edessa meditabunda (Fabricius). Abundance and species richness were the lowest in January, February, and March and the highest in July, August, and September. A combination of high species diversity observed during the colder months, including several unrelated to rice, and the absence of immature specimens in the tussocks strengthens the hypothesis that A. bicornis is a hibernation site for pentatomoids in the region.


Sujet(s)
Heteroptera/physiologie , Hibernation , Poaceae/parasitologie , Andropogon , Animaux , Brésil , Oryza , Saisons
12.
Arq. Inst. Biol. ; 79(2): 185-192, 2012. ilus, tab, graf
Article de Portugais | VETINDEX | ID: vti-5515

RÉSUMÉ

A mosca-das-frutas sul-americana, Anastrepha fraterculus (Wiedemann, 1830) (Diptera: Tephritidae), é a principal praga das frutíferas no Sul do Brasil. Este trabalho buscou caracterizar as populações de moscas-das-frutas desta espécie capturadas em armadilhas com atrativos alimentares, através da comparação do estágio de maturação dos órgãos reprodutivos de fêmeas de campo e de laboratório. Realizaram-se coletas em dois pomares, um de pessegueiro, com manejo convencional e um de goiabeira, sem manejo, durante uma safra, com dois diferentes atrativos alimentares, em diferentes fases das culturas. Foram utilizadas armadilhas do tipo McPhail com suco de uva a 25% e proteína hidrolisada a 5%. As fêmeas coletadas foram dissecadas, seus ovários medidos em largura e comprimento e foi determinado o grau de maturação sexual, assim com as de laboratório, com a idade controlada. Foram capturadas 895 fêmeas de A. fraterculus no pomar de goiabeiras e 139 no de pessegueiros. Determinaram-se três estágios fisiológicos das fêmeas a partir da diferenciação celular dos ovários: imaturas, em desenvolvimento e maduras. Fêmeas maduras de laboratório apresentaram ovários significativamente menores que as de campo. No pomar de pessegueiros identificaram-se, através dos picos de coletas de moscas imaturas, três gerações durante o ciclo da cultura, até a colheita. Nas goiabeiras, o maior pico populacional de moscas imaturas ocorreu no final do ciclo, indicando uma população apta a colonizar outras frutíferas.(AU)


The South American fruit fly, Anastrepha fraterculus (Wiedemann, 1830) (Diptera: Tephritidae) is a major pest of fruit trees in southern Brazil. This study aimed to characterize the populations of fruit flies captured in traps with food baits, through the characterization of reproductive organs of females compared with females of the laboratory strain. Collections were performed in two orchards; the first, peach trees with conventional management; the second, guava trees without management; during a crop cycle. McPhail traps were used with grape juice at 25% and hydrolyzed protein at 5%. Collected females were dissected; their ovaries were measured in width and length, and the degree of sexual maturation was determined. Females maintained in the laboratory, with age controlled, were also dissected to serve as a comparison to the field specimens. A total of 895 females of A. fraterculus were captured in the orchard of guava and 139 in peach trees. Three physiological stages of the females from the ovarian cell differentiation were determined: immature, in development and mature. Ovaries from mature laboratory females were significantly smaller than those from the field. In the peach orchard, through the peaks of immature flies, three generations were identified during the crop cycle, until the harvest. In guava, the population peak of immature flies occurred at the end of the cycle, indicating that the population was able to colonize other fruit.(AU)


Sujet(s)
Animaux , Ovaire/anatomie et histologie , Parasites Agricoles , Reproduction/physiologie , Diptera/classification , Tephritidae/classification
13.
Arq. Inst. Biol. ; 79(2)2012.
Article de Portugais | VETINDEX | ID: vti-698615

RÉSUMÉ

The South American fruit fly, Anastrepha fraterculus (Wiedemann, 1830) (Diptera: Tephritidae) is a major pest of fruit trees in southern Brazil. This study aimed to characterize the populations of fruit flies captured in traps with food baits, through the characterization of reproductive organs of females compared with females of the laboratory strain. Collections were performed in two orchards; the first, peach trees with conventional management; the second, guava trees without management; during a crop cycle. McPhail traps were used with grape juice at 25% and hydrolyzed protein at 5%. Collected females were dissected; their ovaries were measured in width and length, and the degree of sexual maturation was determined. Females maintained in the laboratory, with age controlled, were also dissected to serve as a comparison to the field specimens. A total of 895 females of A. fraterculus were captured in the orchard of guava and 139 in peach trees. Three physiological stages of the females from the ovarian cell differentiation were determined: immature, in development and mature. Ovaries from mature laboratory females were significantly smaller than those from the field. In the peach orchard, through the peaks of immature flies, three generations were identified during the crop cycle, until the harvest. In guava, the population peak of immature flies occurred at the end of the cycle, indicating that the population was able to colonize other fruit.


A mosca-das-frutas sul-americana, Anastrepha fraterculus (Wiedemann, 1830) (Diptera: Tephritidae), é a principal praga das frutíferas no Sul do Brasil. Este trabalho buscou caracterizar as populações de moscas-das-frutas desta espécie capturadas em armadilhas com atrativos alimentares, através da comparação do estágio de maturação dos órgãos reprodutivos de fêmeas de campo e de laboratório. Realizaram-se coletas em dois pomares, um de pessegueiro, com manejo convencional e um de goiabeira, sem manejo, durante uma safra, com dois diferentes atrativos alimentares, em diferentes fases das culturas. Foram utilizadas armadilhas do tipo McPhail com suco de uva a 25% e proteína hidrolisada a 5%. As fêmeas coletadas foram dissecadas, seus ovários medidos em largura e comprimento e foi determinado o grau de maturação sexual, assim com as de laboratório, com a idade controlada. Foram capturadas 895 fêmeas de A. fraterculus no pomar de goiabeiras e 139 no de pessegueiros. Determinaram-se três estágios fisiológicos das fêmeas a partir da diferenciação celular dos ovários: imaturas, em desenvolvimento e maduras. Fêmeas maduras de laboratório apresentaram ovários significativamente menores que as de campo. No pomar de pessegueiros identificaram-se, através dos picos de coletas de moscas imaturas, três gerações durante o ciclo da cultura, até a colheita. Nas goiabeiras, o maior pico populacional de moscas imaturas ocorreu no final do ciclo, indicando uma população apta a colonizar outras frutíferas.

14.
Arq. Inst. Biol. (Online) ; 79(2): 185-192, 2012. ilus, tab, graf
Article de Portugais | VETINDEX | ID: biblio-1461739

RÉSUMÉ

A mosca-das-frutas sul-americana, Anastrepha fraterculus (Wiedemann, 1830) (Diptera: Tephritidae), é a principal praga das frutíferas no Sul do Brasil. Este trabalho buscou caracterizar as populações de moscas-das-frutas desta espécie capturadas em armadilhas com atrativos alimentares, através da comparação do estágio de maturação dos órgãos reprodutivos de fêmeas de campo e de laboratório. Realizaram-se coletas em dois pomares, um de pessegueiro, com manejo convencional e um de goiabeira, sem manejo, durante uma safra, com dois diferentes atrativos alimentares, em diferentes fases das culturas. Foram utilizadas armadilhas do tipo McPhail com suco de uva a 25% e proteína hidrolisada a 5%. As fêmeas coletadas foram dissecadas, seus ovários medidos em largura e comprimento e foi determinado o grau de maturação sexual, assim com as de laboratório, com a idade controlada. Foram capturadas 895 fêmeas de A. fraterculus no pomar de goiabeiras e 139 no de pessegueiros. Determinaram-se três estágios fisiológicos das fêmeas a partir da diferenciação celular dos ovários: imaturas, em desenvolvimento e maduras. Fêmeas maduras de laboratório apresentaram ovários significativamente menores que as de campo. No pomar de pessegueiros identificaram-se, através dos picos de coletas de moscas imaturas, três gerações durante o ciclo da cultura, até a colheita. Nas goiabeiras, o maior pico populacional de moscas imaturas ocorreu no final do ciclo, indicando uma população apta a colonizar outras frutíferas.


The South American fruit fly, Anastrepha fraterculus (Wiedemann, 1830) (Diptera: Tephritidae) is a major pest of fruit trees in southern Brazil. This study aimed to characterize the populations of fruit flies captured in traps with food baits, through the characterization of reproductive organs of females compared with females of the laboratory strain. Collections were performed in two orchards; the first, peach trees with conventional management; the second, guava trees without management; during a crop cycle. McPhail traps were used with grape juice at 25% and hydrolyzed protein at 5%. Collected females were dissected; their ovaries were measured in width and length, and the degree of sexual maturation was determined. Females maintained in the laboratory, with age controlled, were also dissected to serve as a comparison to the field specimens. A total of 895 females of A. fraterculus were captured in the orchard of guava and 139 in peach trees. Three physiological stages of the females from the ovarian cell differentiation were determined: immature, in development and mature. Ovaries from mature laboratory females were significantly smaller than those from the field. In the peach orchard, through the peaks of immature flies, three generations were identified during the crop cycle, until the harvest. In guava, the population peak of immature flies occurred at the end of the cycle, indicating that the population was able to colonize other fruit.


Sujet(s)
Animaux , Ovaire/anatomie et histologie , Parasites Agricoles , Reproduction/physiologie , Diptera/classification , Tephritidae/classification
15.
Neotrop Entomol ; 40(5): 529-32, 2011 Oct.
Article de Anglais | MEDLINE | ID: mdl-22068937

RÉSUMÉ

Grapholita molesta (Busck) is one of the major pests of Rosaceae, causing significant damage to buds and fruits. In Southern Brazil, its population density is reduced during Rosaceae dormancy months. The present study evaluated the influence of different photoperiods (L:D) (10:14, 11:13, 12:12, 13:11, 14:10 and 16:8) at 25 ± 1ºC and 60 ± 10% RH on diapause induction of G. molesta eggs, larvae, prepupae, and pupae. The effects of the photoperiod on the life cycle of non-diapausing insects and on the second generation were also assessed. Prepupal diapause was observed only when eggs and neonates (≤ 12h-old larvae) were exposed to photophases from 10h to 14h long. Development of non-diapausing individuals and those from the second generation tended to be longer in photophases between 10h and 14h long.


Sujet(s)
Lepidoptera/croissance et développement , Étapes du cycle de vie , Photopériode , Animaux
16.
Neotrop Entomol ; 40(2): 212-6, 2011.
Article de Anglais | MEDLINE | ID: mdl-21584402

RÉSUMÉ

Antennal sensilla of Anastrepha fraterculus (Wied.) were examined using scanning electron microscopy. In the flagellum, there are trichoid, basiconic, clavate type I and II, and styloconic sensilla and microtrichia. Only microtrichiae and chaetica sensilla were observed in the scape and pedicel. The number of sensilla in the flagellum was similar between sexes. At the apex there was a higher density of trichoid and an absence of clavate sensilla, while basiconic sensilla were more abundant in the proximal region.


Sujet(s)
Antennes des arthropodes/anatomie et histologie , Sensilles/anatomie et histologie , Tephritidae/anatomie et histologie , Animaux , Microscopie électronique à balayage
17.
Arq. Inst. Biol. (Online) ; 78(1): 31-35, jan-mar, 2011. ilus, tab
Article de Portugais | LILACS, VETINDEX | ID: biblio-1396194

RÉSUMÉ

Nesse estudo foi descrita, mensurada e ilustrada, a genitália interna de machos e fêmeas de Spartocera dentiventris considerando distintas idades. As alterações mais evidentes no sistema reprodutivo foram observadas na largura e no comprimento dos ovários que permitem a distinção entre os estágios imaturo e reprodutivo. As medidas dos órgãos de reprodução de machos não apresentam diferenças significativas nas diferentes idades.


In this work, the internal reproductive organs of Spartocera dentiventris males and females with different ages are described, measured and illustrated. The most significant changes in the reproductive organs were found in the length and width of ovaries, which permit the distinction between immature and reproductive stages. No significant difference was found among the measurements of the reproductive structures of males at the different ages.


Sujet(s)
Heteroptera/anatomie et histologie , Système génital/anatomie et histologie , Facteurs âges
18.
Arq. Inst. Biol. (Online) ; 78(1): 37-43, jan-mar, 2011. tab, graf
Article de Portugais | LILACS, VETINDEX | ID: biblio-1396272

RÉSUMÉ

A mosca-das-frutas, Anastrepha fraterculus, tem, como principais hospedeiros primários, frutos de Myrtaceae. O tamanho do inseto pode ser indicador de aptidão e fecundidade, sendo os estudos morfométricos utilizados para auxiliar nestas identificações. Este trabalho objetivou verificar a associação entre peso dos frutos, pupários e tamanho das asas das moscas-das-frutas que se desenvolveram em diferentes mirtáceas. Foram amostrados frutos de araçazeiro-amarelo, araçazeiro-vermelho, goiabeira e goiabeira-serrana em cinco árvores de cada espécie. Os frutos foram pesados e os pupários oriundos destes pesados e individualizados. Registrou-se o número, sexo e área total da asa direita das moscas. Comparou-se o peso médio dos frutos, dos pupários e o tamanho de asas. O peso médio dos pupários foi maior em goiaba e araçá-vermelho. A maior área média de asa foi registrada nos indivíduos emergidos de goiabas e a menor, nos de araçá-amarelo. O peso dos frutos e dos pupários em araçá-amarelo, vermelho e goiaba-serrana não apresentaram associação significativa. Nas goiabeiras, a correlação entre o peso dos frutos e o dos pupários foi negativa. O peso dos frutos e a área da asa das moscas provenientes das espécies de mirtáceas não evidenciaram correlação. Os resultados indicam que a mosca é capaz de desenvolver-se de forma semelhante nas espécies de mirtáceas amostradas.


The fruit-fly Anastrepha fraterculus uses the myrtacean fruits as its main primary hosts. The insect size might be an indicator of aptitude and fecundity, and morphometric studies are used to help in those identifications. This study aimed to verify the association among fruit weight, puparial weight and wing size of fruit-flies that developed in different myrtacean species. Yellow strawberry guava, cattle guava, guava and feijoa fruits were sampled from 5 trees of each species. The fruits were weighed, and the puparia originated from them were also weighed and individualized. The number, gender and total right-wing area of the flies were registered. Mean fruit and puparial weights and wing sizes were compared. Mean puparial weight was higher in guava and cattle guava. The largest mean wing area was recorded for individuals from guavas; the smallest, for those from yellow strawberry guava. The fruit and puparial weights did not present a significant association in yellow strawberry guava, cattle guava and feijoa. In guavas, the correlation between fruit and puparial weights was negative. The fruit weight and wing area in all myrtacean species did not show any correlation. These results indicate the fly is able to develop similarly in all sampled myrtacean species.


Sujet(s)
Myrtaceae/parasitologie , Tephritidae/anatomie et histologie , Tephritidae/croissance et développement
19.
Arq. Inst. Biol. ; 78(1)2011.
Article de Portugais | VETINDEX | ID: vti-759489

RÉSUMÉ

ABSTRACT The fruit-fly Anastrepha fraterculus uses the myrtacean fruits as its main primary hosts. The insect size might be an indicator of aptitude and fecundity, and morphometric studies are used to help in those identifications. This study aimed to verify the association among fruit weight, puparial weight and wing size of fruit-flies that developed in different myrtacean species. Yellow strawberry guava, cattle guava, guava and feijoa fruits were sampled from 5 trees of each species. The fruits were weighed, and the puparia originated from them were also weighed and individualized. The number, gender and total right-wing area of the flies were registered. Mean fruit and puparial weights and wing sizes were compared. Mean puparial weight was higher in guava and cattle guava. The largest mean wing area was recorded for individuals from guavas; the smallest, for those from yellow strawberry guava. The fruit and puparial weights did not present a significant association in yellow strawberry guava, cattle guava and feijoa. In guavas, the correlation between fruit and puparial weights was negative. The fruit weight and wing area in all myrtacean species did not show any correlation. These results indicate the fly is able to develop similarly in all sampled myrtacean species.


RESUMO A mosca-das-frutas, Anastrepha fraterculus, tem, como principais hospedeiros primários, frutos de Myrtaceae. O tamanho do inseto pode ser indicador de aptidão e fecundidade, sendo os estudos morfométricos utilizados para auxiliar nestas identificações. Este trabalho objetivou verificar a associação entre peso dos frutos, pupários e tamanho das asas das moscas-das-frutas que se desenvolveram em diferentes mirtáceas. Foram amostrados frutos de araçazeiro-amarelo, araçazeiro-vermelho, goiabeira e goiabeira-serrana em cinco árvores de cada espécie. Os frutos foram pesados e os pupários oriundos destes pesados e individualizados. Registrou-se o número, sexo e área total da asa direita das moscas. Comparou-se o peso médio dos frutos, dos pupários e o tamanho de asas. O peso médio dos pupários foi maior em goiaba e araçá-vermelho. A maior área média de asa foi registrada nos indivíduos emergidos de goiabas e a menor, nos de araçá-amarelo. O peso dos frutos e dos pupários em araçá-amarelo, vermelho e goiaba-serrana não apresentaram associação significativa. Nas goiabeiras, a correlação entre o peso dos frutos e o dos pupários foi negativa. O peso dos frutos e a área da asa das moscas provenientes das espécies de mirtáceas não evidenciaram correlação. Os resultados indicam que a mosca é capaz de desenvolver-se de forma semelhante nas espécies de mirtáceas amostradas.

20.
Arq. Inst. Biol. ; 78(1)2011.
Article de Portugais | VETINDEX | ID: vti-759488

RÉSUMÉ

ABSTRACT In this work, the internal reproductive organs of Spartocera dentiventris males and females with different ages are described, measured and illustrated. The most significant changes in the reproductive organs were found in the length and width of ovaries, which permit the distinction between immature and reproductive stages. No significant difference was found among the measurements of the reproductive structures of males at the different ages.


RESUMO Nesse estudo foi descrita, mensurada e ilustrada, a genitália interna de machos e fêmeas de Spartocera dentiventris considerando distintas idades. As alterações mais evidentes no sistema reprodutivo foram observadas na largura e no comprimento dos ovários que permitem a distinção entre os estágios imaturo e reprodutivo. As medidas dos órgãos de reprodução de machos não apresentam diferenças significativas nas diferentes idades.

SÉLECTION CITATIONS
DÉTAIL DE RECHERCHE