Distribuição vertical de Crysodeixis includens (Lepidoptera: Noctuidae) em cultivar transgênica e convencional de algodoeiro

The aim of this study was to evaluate the intra-plant distribution of Crysodeixis includens in conventional FM 993 and transgenic FM 975 WS (WideStrike), which express the toxic proteins Cry1Ac and Cry1F. The experiment was carried out in a split-plot design arranged under a complete block design with six treatments (three thirds x two plant leaf surface) and 40 repetitions. The plants were visually divided into three thirds (upper, middle and lower) and into adaxial and abaxial leaves, registering the number of caterpillars. C includens caterpillars were found at higher numbers in the non-Bt cultivar (FM 993), while in the transgenic cultivar FM 975 WS (WideStrike) were found only small caterpillars, and significantly fewer compared to their non-Bt isoline (FM 993). Caterpillars, regardless of size and cultivar, were most commonly found at the bottom and middle thirds of the plant canopy and on the abaxial leaf surface.O objetivo deste estudo foi avaliar a distribuição intra-planta de lagartas de Crysodeixis includens no cultivar convencional FM 993 e na sua isolinha transgênica FM 975 WS (WideStrike), que expressa as proteínas tóxicas Cry1Ac e Cry1F. O experimento foi realizado com o delineamento em blocos casualizados em esquema de parcelas subdivididas, com seis tratamentos (três terços da planta x duas faces foliares) e 40 repetições. As plantas foram visualmente divididas em três terços (superior, médio e inferior) e nas faces adaxial e abaxial das folhas, registrando-se o número de lagartas. Lagartas de C. includens foram identificadas em maior número no cultivar não-Bt (FM 993), enquanto que, na cultivar transgênica FM 975 WS (WideStrike), foram constatadas apenas as pequenas, em número significativamente menor que na sua isolinha não-Bt (FM 993). As lagartas, independentemente do tamanho e do cultivar, foram mais encontradas na parte inferior e mediana do dossel das plantas e, ainda, na face abaxial das folhas

Ecologia química no controle biológico de fitófagos e respectivos predadores e parasitoides

O Controle Biológico Natural, ou Conservativo, é uma ferramenta indispensável para o sucesso do Manejo Integrado de Pragas, pois permite uma interação entre os componentes do ambiente, o que o coloca na linha de frente das táticas e estratégias de manejo de pragas em agroecossistemas. Basicamente, esta interação, denominada interação tritrófica, envolve as plantas, os organismos fitófagos e seus inimigos naturais. Neste contexto, diversos fatores são importantes para o controle biológico, tais como condições abióticas e bióticas, destacando-se características das plantas (compostos metabólitos secundários e arquitetura, por exemplo) e potenciais presas/hospedeiros (semioquímicos, etc.). Inimigos naturais podem utilizar estes recursos durante o seu processo de busca e localização do hospedeiro, de modo que o conhecimento sobre o comportamento de inimigos naturais em função da fenologia e arquitetura das plantas, bem como sobre o potencial de voláteis emitidos por plantas e presas é fundamental para um programa de manejo integrado de pragas. Desta forma, o presente trabalho teve por objetivos: a) avaliar a dinâmica populacional e a distribuição vertical de ovos de Chrysodeixis includens (Lepidoptera: Noctuidae) e de seus ovos parasitados por Trichogramma spp. (Hymenoptera: Trichogrammatidae) na cultura da soja; b) determinar a resposta comportamental do percevejo predador Orius insidiosus (Hemiptera: Anthocoridae) para voláteis associados à Halyomorpha halys (Hemiptera: Pentatomidae). Sendo assim, em Jaboticabal, SP, Brasil, durante as safras agrícolas de 2012/13 e 2013/14, foram realizadas coletas de ovos de C. includens presentes em diferentes terços das plantas de soja, durante diferentes estádios fenológicos da cultura. Semanalmente, o número de ovos presentes nas plantas foi anotado e os mesmos eram coletados e levados para laboratório para aguardar a emergência de lagartas ou de adultos de Trichogramma spp. O número de adultos do parasitoide emergido por ovo era registrado, bem como a razão sexual. Os adultos foram identificados ao nível específico, encontrando-se a espécie Trichogramma pretiosum presente na cultura da soja. Fêmeas de C. includens preferiram ovipositar com mais intensidade nos terços médio e inferior das plantas, principalmente durante os estádios reprodutivos da cultura. O parasitismo de ovos por T. pretiosum apresentou uma tendência semelhante, em que a medida que se aumentou a densidade de ovos de C. includens nas plantas, também elevou-se o número médio de ovos parasitados, indicando uma forte correlação positiva entre a praga e o inimigo natural. Para atingir o segundo objetivo desta tese, e fornecer alternativas para o controle biológico de H. halys, um pentatomídeo invasor nos EUA, foram conduzidos experimentos para testar a atratividade de O. insidiosus para voláteis emitidos pela presa e por plantas de feijoeiro atacadas por ela. Foram conduzidos experimentos em casa-de-vegetação, laboratório e em campo, em que foi identificado altas concentrações do composto tridecano. Foi avaliado a atratividade de O. insidiosus para diferentes concentrações deste composto, bem como os efeitos desta atração na predação de ovos. Foi observado que O. insidiosus é atraído por tridecano, no entanto, esta atração não afeta a predação de ovos, em casa de vegetação e no campo.Natural ou Conservative Biological Control is a valuable tool for the success of Integrated Pest Management as it allows a natural interaction between the components of the environment, which places it at the forefront of the tactics and pest management strategies in agroecosystems. This interaction, so-called tritrophic interaction, involves plants, phytophagous organisms and their natural enemies. In this context several factors are important for biological control, such as biotic and abiotic conditions, highlighting plant characteristics (secondary metabolites compounds and plant architecture, for example) and possible prey/hosts (semiochemicals, etc.). Natural enemies can use this information during the its host foraging behavior, so the knowledge of the behavior of natural enemies according to the phenology and plant architecture as well as potential volatiles emitted by prey plants and potential is key for an integrated pest management program. Thus, this study aimed to: a) assess the population dynamics and vertical distribution of natural biological control of Chrysodeixis includens (Lepidoptera: Noctuidae) eggs by Trichogramma spp. (Hymenoptera: Trichogrammatidae) in soybean field; b) determine the behavioral response of the predator Orius insidiosus (Hemiptera: Anthocoridae) for volatile associated with Halyomorpha halys (Hemiptera: Pentatomidae). Thus, in Jaboticabal, SP, Brazil, during the growing seasons of 2012/2013 and 2013/2014, samples were taken from C. includens eggs present on different thirds of soybean plants during different phenological stages of the crop. Weekly, number of eggs present in plants was recorded and the eggs were collected ant taken to the laboratory to await the emergence of larvae or adult Trichogramma spp. The number of adult Trichogramma spp. emerged per egg was noted, as was the sex ratio. The adults were identified to species level, finding Trichogramma pretiosum as the main species present in soybeans. Females of C. includens intensively preferred to lay eggs in the middle and lower thirds of the plants, especially during the reproductive stages of soybean plants. Egg parasitism by T. pretiosum presented a similar tendency, which as the C. includens eggs density increased in plants, also increased the average number of parasitized eggs, indicating a strong positive correlation between the pest and the natural enemy. To achieve the second objective of this thesis, and provide alternatives for the biological control of H. halys (an invasive pentatomid in the US). experiments were conducted to test the attractiveness of O. insidiosus to volatiles emitted by the prey and bean plants attacked by it. Experiments were conducted under greenhouse, laboratory and field conditions. It was identified that tridecane was the major compound in damage-bean pods as well as on H. halys. The attractiveness of O. insidiosus was evaluated for different concentrations of this compound as well as the effects of this attraction as predators of eggs. It was observed that O. insidiosus is attracted to tridecane, however, this attraction not poisitivamente affected the predation of eggs in the greenhouse and in the field.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Distribuição vertical e temporal de ovos de Alabama argillacea e de Heliothis virescens (Lepidoptera: Noctuidae) e parasitismo natural por Trichogramma pretiosum (Hymenoptera: Trichogrammatidae)

O conhecimento do comportamento de infestação dos insetos em sistemas agrícolas facilita as amostragens, economiza tempo sem perder a confiabilidade para a tomada de decisões no sistema de manejo de pragas. Assim o objetivo foi estudar a distribuição vertical e temporal de ovos de Alabama argillacea e de Heliothis virescens, e o parasitismo de ovos por Trichogramma pretiosum em cultivares de algodoeiro. O delineamento experimental foi em blocos ao acaso, com cinco tratamentos (cultivares DeltaOPAL, FMX-933, FMT-701, FMX-910 e NuOPAL), com oito repetições. As avaliações foram semanais, a partir da emergência das plantas. Para a distribuição vertical, as plantas foram avaliadas nas partes superior, média e inferior, anotando-se o número de ovos. Os ovos de A. argillacea e de H. virescens foram parasitados por Trichogramma pretiosum. Não houve preferência para oviposição por A. argillacea e por H. virescens durante os estágios fenológicos das plantas, tal como o grau de parasitismo por T. pretiosum também não foi influenciado. Quanto à distribuição vertical dos ovos, o terço superior e o médio das plantas foram os mais preferidos para oviposição por A. argillacea nas cultivares NuOPAL, DeltaOPAL e FMX-910, enquanto que H. virescens preferiu ovipositar no terço superior das plantas. T. pretiosum preferiu ovipositar em ovos de A. argillacea presentes no terço superior e médio das plantas, sendo que ovos de H. virescens presentes no terço superior das plantas foram mais parasitados por T. pretiosumThe knowledge of a pest infestation behavior on agricultural areas help the sampling and reduce time without lose confidence on decisions in integrated pest management. This work aimed to study the vertical and temporal distribution of Alabama argillacea and Heliothis virescens eggs, as well as parasitism of its eggs by Trichogramma pretiosum in cotton cultivars. The experimental design was randomized blocks with five treatments with five treatments (cultivars DeltaOPAL, FMX-933, FMT-701 and FMX-910 and NuOPAL) and with eight replicates. Evaluations were performed weekly since plant emergence. For the vertical distribution, plants were divided into three parts, upper, middle and bottom. The number of eggs present in plants was recorded. A. argillacea and H. virescens eggs were parasitized by Trichogramma pretiosum. There was no preference for oviposition by A. argillacea and H. virescens during the plants phenological stages, as well as T. pretiosum parasitism. Concerning the vertical distribution of eggs, the upper and middle parts of the plants were the most preferred for oviposition by A. argillacea on cultivars NuOPAL, DeltaOPAL and FMX-910, and H. virescens preferred to oviposit in the upper part of the plants. T. pretiosum preferred to oviposit in A. argillacea eggs on the upper and middle parts of the plants, and in H. virescens on the upper part of the plantsConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Sequential sampling of Euschistus heros (Heteroptera: Pentatomidae) in soybean

Integrated pest management programs for soybean (Glycine max (L.) Merrill) must be based on efficient sampling plans for estimating the pest population. Based on the spatial distribution of the Neotropical brown stink bug Euschistus heros (Fabricius, 1794) found on soybean, it was possible to construct a sequential sampling plan for the survey of this insect found on soybean. The experiment was carried out during two growing seasons, 2010/2011 and 2011/2012, using the transgenic soybean cultivar M 7908 RR, in plots of 10,000 m² subdivided into 100 plots of 100 m² (10 m × 10 m). Nymphs >; 0.5 cm (4th and 5th instars) plus adults were counted weekly from five drop cloth technique samplings per plot. To evaluate insect dispersion in the area, the following indices were used: variance/mean ratio, Morisita's index, Green's coefficient, the k exponent of the negative binomial distribution, and estimation of the common exponent k (kc). To study probabilistic models to describe the spatial distribution of the insects, adjustments of the Poisson and negative binomial distributions were tested. Two sequential sampling plans for separate fields, one for grain production and the other for seed production, were prepared. The data fitted a negative binomial distribution and a sampling plan was drawn up using the sequential likelihood ratio test (SLRT). The maximum sampling unit number expected for control-related decision making was six in grain production fields, and nine in seed production fields

Errata para Distribuição vertical de Crysodeixis includens (Lepidoptera: Noctuidae) em cultivar transgênica e convencional de algodoeiro

CORRECTION TO THE TITLE OF THE ARTICLE:Distribuição vertical de Chrysodeixis includens (Lepidoptera: Noctuidae) em cultivar transgênica e convencional de algodoeiro Related content:Distribuição vertical de Crysodeixis includens (Lepidoptera: Noctuidae) em cultivar transgênica e convencional de algodoeiroMarina Funichello, Diego Felisbino Fraga, Evandro Pereira Prado, Oniel Jeremias Aguirre-Gil e Antonio Carlos BusoliRevista de Ciências Agroveterinárias | Vol. 18 | p. 150-153.CORREÇÃO NO TÍTULO DO ARTIGO:Distribuição vertical de Chrysodeixis includens (Lepidoptera: Noctuidae) em cultivar transgênica e convencional de algodoeiroArtigo relacionado:Distribuição vertical de Crysodeixis includens (Lepidoptera: Noctuidae) em cultivar transgênica e convencional de algodoeiroMarina Funichello, Diego Felisbino Fraga, Evandro Pereira Prado, Oniel Jeremias Aguirre-Gil e Antonio Carlos BusoliRevista de Ciências Agroveterinárias | Vol. 18 | p. 150-153

Within plant distribution of Anthonomus grandis (Coleoptera: Curculionidae) feeding and oviposition damages in cotton cultivars Distribuição vertical de botões florais com danos de alimentação e de oviposição de Anthonomus grandis (Coleoptera: Curculionidae) em cultivares de algodoeiro

The feeding and oviposition behavior of boll weevil in new cotton cultivars is essential for an adequate management. The objective of this study was to evaluate the vertical distribution of squares punctured for feeding and oviposition of the pest in the cultivars NuOPAL, DeltaOPAL, FMT-701, FMX-910 and FMX-993, and record the most and least preferred times of feeding and oviposition. The number of squares used for boll weevil feeding and oviposition were evaluated weekly in three parts of plant canopy. It was observed that, regardless the cultivar, A. grandis preferred to lay eggs in squares located in the upper part and feed on squares in the middle and upper parts. The boll weevil preferred to feed on cultivar FMT-701 in the beginning of the period of cotton flowering and fruiting, and the cultivars NuOPAL, DeltaOPAL, FMX-910 and FMX-993 throughout the whole period of flowering and fruiting. A. grandis preferred to lay eggs on cultivars NuOPAL, FMT-701 and FMX-993 at the beginning and end of flowering and fruiting of plants, while the cultivars DeltaOPAL and FMX-910 are used for oviposition throughout the period of flowering and fruiting.O conhecimento do comportamento de alimentação e de oviposição de Anthonomus grandis em cultivares recentes de algodoeiro é essencial para seu manejo. Neste trabalho, objetivou-se avaliar a distribuição vertical de botões florais com orifícios de alimentação e de oviposição da praga nas cultivares NuOPAL, DeltaOPAL, FMT-701, FMX-910 e FMX-993, bem como registrar as épocas de maior e menor preferência alimentar e de oviposição. O experimento foi conduzido em Jaboticabal, SP, Brasil, safra 2010/2011. Foram realizadas avaliações semanais, baseadas no número de botões florais, utilizados para alimentação e para oviposição pelo bicudo-do-algodoeiro, em três regiões do dossel das plantas. Observou-se que A. grandis preferiu ovipositar em botões florais localizados no terço superior das plantas e se alimentar de botões florais localizados nos terços médio e superior das plantas. A cultivar FMT-701 foi mais utilizada para a alimentação do bicudo, no início do período de florescimento e frutificação, e as cultivares NuOPAL, DeltaOPAL, FMX-910 e FMX-993 são utilizadas em todo o período de florescimento e frutificação das plantas. A. grandis preferiu ovipositar nas cultivares NuOPAL, FMT-701 e FMX-993, no início e no final do período de florescimento e frutificação e as cultivares DeltaOPAL e FMX-910 foram mais ovipositadas durante todo o período de florescimento e frutificação das plantas

Sequential sampling of Euschistus heros (Heteroptera: Pentatomidae) in soybean

Integrated pest management programs for soybean (Glycine max (L.) Merrill) must be based on efficient sampling plans for estimating the pest population. Based on the spatial distribution of the Neotropical brown stink bug Euschistus heros (Fabricius, 1794) found on soybean, it was possible to construct a sequential sampling plan for the survey of this insect found on soybean. The experiment was carried out during two growing seasons, 2010/2011 and 2011/2012, using the transgenic soybean cultivar M 7908 RR, in plots of 10,000 m(2) subdivided into 100 plots of 100 m(2) (10 m x 10 m). Nymphs > 0.5 cm (4th and 5th instars) plus adults were counted weekly from five drop cloth technique samplings per plot. To evaluate insect dispersion in the area, the following indices were used: variance/mean ratio, Morisita's index, Green's coefficient, the k exponent of the negative binomial distribution, and estimation of the common exponent k (kc). To study probabilistic models to describe the spatial distribution of the insects, adjustments of the Poisson and negative binomial distributions were tested. Two sequential sampling plans for separate fields, one for grain production and the other for seed production, were prepared. The data fitted a negative binomial distribution and a sampling plan was drawn up using the sequential likelihood ratio test (SLRT). The maximum sampling unit number expected for control-related decision making was six in grain production fields, and nine in seed production fields.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Infestation of Anthonomus grandis (Coleoptera: Curculionidae) on re-sprout of cotton plants

The destruction of cotton crop residues at the end of the crop cycle is a key strategy for the phytosanitary crop management, since its off-season re-sprout can provide sites for feeding and oviposition of pests such as the boll weevil. This study aimed to evaluate the re-sprout capacity of cotton cultivars, as well as their infestation by Anthonomus grandis. A randomized blocks design, in a 3 x 2 factorial arrangement, with three cultivars (FM 910, DeltaOPAL and NuOPAL), two mowing heights (10 cm and 20 cm) and four replications, was used. Weekly evaluations were carried out for measuring the percentage of plant re-sprout for both mowing heights, percentage of flower buds infested by the boll weevil and number of adults per re-sprout. Plants mowed at 10 cm presented a lower sprout capacity and consequently less flower buds, reducing the boll weevil population density in the area, while plants mowed at 20 cm showed high re-sprouts rates, seven days after mowing. The FM 910 cultivar had the highest number of re-sprout plants, while the DeltaOPAL cultivar showed the highest number of flower buds and adults per plant, as well as the highest percentage of buds damaged by the boll weevil