Navegando por Autor "Picanço, Marcelo Coutinho"
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Item An analysis of sensitivity of CLIMEX parameters in mapping species potential distribution and the broad-scale changes observed with minor variations in parameters values: an investigation using open-field Solanum lycopersicum and Neoleucinodes elegantalis as an example(Theoretical and Applied Climatology, 2018-04) Silva, Ricardo Siqueira da; Picanço, Marcelo Coutinho; Kumar, Lalit; Shabani, FarzinA sensitivity analysis can categorize levels of parameter influence on a model’s output. Identifying parameters having the most influence facilitates establishing the best values for parameters of models, providing useful implications in species modelling of crops and associated insect pests. The aim of this study was to quantify the response of species models through a CLIMEX sensitivity analysis. Using open-field Solanum lycopersicum and Neoleucinodes elegantalis distribution records, and 17 fitting parameters, including growth and stress parameters, comparisons were made in model performance by altering one parameter value at a time, in comparison to the best-fit parameter values. Parameters that were found to have a greater effect on the model results are termed “sensitive”. Through the use of two species, we show that even when the Ecoclimatic Index has a major change through upward or downward parameter value alterations, the effect on the species is dependent on the selection of suitability categories and regions of modelling. Two parameters were shown to have the greatest sensitivity, dependent on the suitability categories of each species in the study. Results enhance user understanding of which climatic factors had a greater impact on both species distributions in our model, in terms of suitability categories and areas, when parameter values were perturbed by higher or lower values, compared to the best-fit parameter values. Thus, the sensitivity analyses have the potential to provide additional information for end users, in terms of improving management, by identifying the climatic variables that are most sensitive.Item Antibiosis of eight Lycopersicon genotypes to Tuta absoluta (Lepidoptera: Gelechiidae)(Revista Ceres, 2009-05) Moreira, Luciano Andrade; Picanço, Marcelo Coutinho; Silva, Gerson Adriano; Semeão, Altair Arlindo; Casali, Vicente Wagner Dias; Campos, Mateus Ribeiro de; Fernandes, Maria Elisa de Sena; Xavier, Vânia MariaTomato leafminer [Tuta absoluta (Meyrick)] is the most important pest in a numerous regions of tomato production in Brazil. Wild species of Lycopersicon, such as L. hirsutum and L. peruvianum have been used in breeding programs in the attempt of obtaining tomato cultivars with resistance to pests. In this paper, is reported a study on the development and survival of T. absoluta under laboratory conditions on eight tomato genotypes: L. esculentum cv. Santa Clara, L. pimpinellifolium (PI 126931), L. peruvianum (PI 306811; PI 128659; LA 444-1; BG 3286; CNPH 374) and L. hirsutum f. glabratum (PI 134417). Newborn caterpillars were ndividualized in glass tubes with sand where a leaflet petiole was fixed (petioles per glass). The tubes were covered with PVC film and maintained inside a seed incubator at 25° C and 70% relative humidity. Caterpillar development was observed when leaflets were changed, every 3 days, until the second insect generation. Genotype effect on caterpillar mortality was observed only at the second generation (90% on PI 134417 against 33.3% on Santa Clara). PI 134417 caused pupae mortality of 50.68% and 100%, at the first and second generations, respectively, confirming their antibiosis effects. Mortality of genotype Santa Clara was12.12% of pupae, at the second generation. The oviposition period was 5.5 and 8.5 days on PI 134417 and Santa Clara, respectively. The longest developmental period of caterpillars occurred on L. peruvianum and L. hirsutum f. glabratum.Item Bioassay method for toxicity studies of insecticide formulations to Tuta absoluta (meyrick, 1917)(Ciência e Agrotecnologia, 2011-09) Galdino, Tarcísio Visintin da Silva; Picanço, Marcelo Coutinho; Morais, Elisangela Gomes Fidelis de; Silva, Nilson Rodrigues; Silva, Geverson Aelton Rezende da; Lopes, Mayara CristinaChemical control is the main method for controlling the tomato leafminer, Tuta absoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae). Reported techniques for the evaluation of insecticide toxicity to the tomato leafminer are not in agreement with field conditions and do not allow us to verify whether doses used in the field are efficient for control. Thus, the objective of this work was to develop a bioassay methodology to study the toxicity of insecticide formulations to T. absoluta that represent field conditions for fast-acting insecticides (neurotoxics and inhibitors of respiration) and slow-acting insecticides (Bacillus thuringiensis and insect growth regulators). The leaf-dip method was the most efficient method for toxicity studies of insecticides formulations to T. absoluta. We verified that bioassays with fast-acting insecticides should be performed with glass Petri dishes containing one tomato foliole from the 4th leaf from the plant apex infested with 10 larvae of 3rd instar and these bioassays can last 48 hours. Conversely, bioassays with slow-acting insecticides should be performed with two-liter transparent PET bottles containing the 4th leaf from the plant apex, with their petioles immersed in a glass bottle containing 120 mL of water, and this leaf should be infested with 10 larvae of 2nd instar and this bioassays can last seven days.Item Biologia e tabela de vida do ácaro-vermelho Tetranychus bastosi em pinhão-manso(Pesquisa Agropecuária Brasileira, 2013-03-15) Pedro Neto, Marçal; Sarmento, Renato Almeida; Oliveira, Wennder Parente de; Picanço, Marcelo Coutinho; Erasmo, Eduardo Andrea LemusO objetivo deste trabalho foi determinar a biologia e a tabela de vida de Tetranychus bastosi em pinhão-manso (Jatropha curcas). O experimento foi realizado em ambiente controlado a 26ºC e 75% de UR, com fotófase de 12 horas. Os ovos usados nos experimentos foram oriundos de criação estoque. As avaliações foram realizadas duas vezes ao dia, para a biologia do ácaro, e uma vez, para os parâmetros reprodutivos. O ciclo médio de vida das fêmeas foi de 9,63 dias e o dos machos, de 8,94 dias. A razão sexual foi 0,65 e a longevidade média das fêmeas foi de 16 dias, com produção média de 59 ovos por fêmea. Os parâmetros de tabela de vida obtidos foram: taxa líquida de reprodução (Ro), 45,41 indivíduos; duração média das gerações (T), 12,66 dias; taxa intrínseca de crescimento (rm), 0,0538 fêmea por fêmea por dia; razão finita de aumento (λ), 1,023 fêmea por fêmea; e tempo para duplicação da população (TD), 3,15 dias. O ácaro T. bastosi desenvolve-se bem e apresenta alto potencial reprodutivo sobre folhas de pinhão-manso.Item Ciclo de vida de microteca Ochroloma Stal,1860 (Coleoptera, Chrysomelidae, Chrys Omelinae)(Revista Ceres, 2003-03-19) Marquini, Flávio; Picanço, Marcelo Coutinho; Moura, Marcelo Fialho de; Oliveira, Ivênio Rubens deEste trabalho teve por objetivo estudar a morfologia externa, longevidade e viabilidade das fases do ciclo de vida de MicrotheCa ochroloma. Este inseto foi criado a 27 11: 2ºC, 80 :l: 10% de umidade relativa e fotofase de 12 horas em couve-chinesa (Brassíca chinensis L.). Os ovos são laranja, oblongos e têm 1,53 de m de comprimento e 0,59 mm de largura. O período de incubação e a viabilidade dos ovos foram de 5,80 dias e 65,60%. Foram observados três ínstares larvais. As larvas são carabiformes, com cápsula cefálica marrom de 0,42; 0,82; e 1,03 mm de largura no primeiro, segundo e terceiro ínstares, respectivamente. O comprimento e largura corporais de larvas de primeiro, segundo e terceiro ínstares foram de 2,02; 4,41; e 6,09 mm e 0,64; 1,55; e 2,15 mm, respectivamente. A duração e viabilidade do primeiro, segundoe terceiro ínstares larvais foram de 1,83; 2,10; e 3,98 dias e 93,00; 96,80; e 96,70%, respectivamente. As pupas eram marrons e possuíam 6,07 mm de comprimento e 4,10 mm de largura. A duração e viabilidade de fase pupal foram de 7,75 dias e 93,1%. A longevidade dos adultos foi de 94 dias.Item Climate model for seasonal variation in Bemisia tabaci using CLIMEX in tomato crops(International Journal of Biometeorology, 2019-03) Ramos, Rodrigo Soares; Silva, Ricardo Siqueira da; Araújo, Tamíris Alves de; Picanço, Marcelo Coutinho; Kumar, Lalit; Shabani, FarzinThe whitefly, Bemisia tabaci, is considered one of the most important pests for tomato Solanum lycopersicum. The population density of this pest varies throughout the year in response to seasonal variation. Studies of seasonality are important to understand the ecological dynamics and insect population in crops and help to identify which seasons have the best climatic conditions for the growth and development of this insect species. In this research, we used CLIMEX to estimate the seasonal abundance of a species in relation to climate over time and species geographical distribution. Therefore, this research is designed to infer the mechanisms affecting population processes, rather than simply provide an empirical description of field observations based on matching patterns of meteorological data. In this research, we identified monthly suitability for Bemisia tabaci, with the climate models, for 12 commercial tomato crop locations through CLIMEX (version 4.0). We observed that B. tabaci displays seasonality with increased abundance in tomato crops during March, April, May, June, October and November (first year) and during March, April, May, September and October (second year) in all monitored areas. During this period, our model demonstrated a strong agreement between B. tabaci density and CLIMEX weekly growth index (GIw), which indicates significant reliability of our model results. Our results may be useful to design sampling and control strategies, in periods and locations when there is high suitability for B. tabaci.Item Coccinellidae, Syrphidae and Aphidoletes are key mortality factors for Myzus persicae in tropical regions: A case study on cabbage crops(Crop Protection, 2018-10) Fidelis, Elisângela Gomes; Carmo, Daiane das Graças do; Santos, Abraão Almeida; Farias, Elizeu de Sá; Silva, Ricardo Siqueira da; Picanço, Marcelo CoutinhoNatural factors regulate Myzus persicae populations in Brassicaceae crops. Ecological life table analysis is a robust tool that allows the estimation of the mortality caused by these factors. Here, we report the natural mortality of M. persicae caused by abiotic and biotic factors assessed by cohort life tables in cabbage crops. Together, these factors accounted for 94.6% mortality in M. persicae populations. The key mortality factor was predation by Coccinellidae larvae (Coccinella septempunctata, Cycloneda sanguinea, Eriopis connexa and Harmonia axyridis), Syrphidae (Allograpta exotica, Pseudodorus clavatus and Ocyptamus gastrostactus), and Aphidoletes sp. Other mortality factors included parasitism, rainfall, entomopathogens and physiological disturbance (e.g., incomplete molting). This information is essential to implement conservation measures of the main predators (key mortality factor) of M. persicae in cabbage crops.Item Corymbia spp. and Eucalyptus spp. essential oils have insecticidal activity against Plutella xylostella(Industrial Crops and Products, 2017-12-15) Filomeno, Claudinei Andrade; Barbosa, Luiz Claudio Almeida; Teixeira, Robson Ricardo; Pinheiro, Antônio Lelis; Farias, Elizeu de Sá; Silva, Eliete Meire de Paula; Picanço, Marcelo CoutinhoPlutella xylostella (L.) is the main brassica pest worldwide and is difficult to control even with commercial insecticides. In this study, assessments were made of the contact toxicity of essential oils (EOs) from ten Myrtaceae species. For this, the leaves of four Corymbia species (C. citriodora, C. intermedia, C. maculata, and C. ptychocarpa) and six Eucalyptus species (E. andrewsii, E. crebra, E. punctata, E. pyrocarpa, E. siderophloia, and E. sphaerocarpa) were collected during the Brazilian dry season and subjected to hydrodistillation for extraction of EOs. For C. citriodora, another sample was also collected during the rainy season. The essential oil (EO) content of all samples ranged from 0.07% w/w to 3.3% w/w and GC–MS analyses allowed the identification of 52 compounds. For E. andrewsii, E. pyrocarpa, and C. ptychocarpa there was no previous report on EO chemical composition. For C. citriodora, a higher EO content for the samples collected during the dry season was found (2.72% versus 1.53% for the rainy season). The insecticidal activity of all eleven EOs was evaluated via topical application on the second-instar larvae of P. xylostella. The most active EOs were produced by C. citriodora collected during the dry season, with citronellal (86.8%) and isopulegol (4.7%) being the main constituents. At 30 μg/mg of insect, these EOs caused 80% P. xylostella mortality, being more active than neem oil used as positive control. These EOs presented low toxicity for Solenopsis saevissima, a natural predator of P. xylostella. Bioassays also demonstrated a synergistic effect between citronellal and (-)-isopulegol at all tested proportions. The results described here suggest that C. citriodora EOs can be an environmentally friendly alternative method to control P. xylostella.Item Critical yield components and key loss factors of tropical cucumber crops(Crop Protection, 2006-10) Bacci, Leandro; Picanço, Marcelo Coutinho; Gonring, Alfredo Henrique Rocha; Guedes, Raul Narciso; Crespo, André Luiz BarretoThe critical components and the key factors of yield losses in autumn–winter and spring–summer cucumber crops were determined and quantified in Viçosa county, State of Minas Gerais, Brazil, in areas cultivated with gynoecium hybrids of the groups Aodai (Sprint 440 II) and “Caipira” (Vlasstar). The data were used to build crop life tables. The overall losses in the autumn–winter and spring–summer cultivations were of 53.5 and 66.6 ton ha−1, representing 76.3% and 59.2% of the overall crop yield potential. A critical component of yield loss was flower abortion in both cultivation periods. Fruit loss in the autumn–winter cultivation period was due to deficient pollination and production of non-marketable fruit size, and fruit damage caused by Diaphania spp. (Lepidoptera: Pyralidae), factors that also affected losses in the spring–summer cultivation period, followed by the physiological disturbance caused by nitrogen deficiency.Item Densidade populacional de alguns insetos em milho exclusivo e consorciado com feijão, em dois sistemas de adubação(Revista Ceres, 2000-10-05) Galvão, João Carlos Cardoso; Silva, Eny do Carmo; Miranda, Glauco Vieira; Bastos, Cristina Schetino; Picanço, Marcelo Coutinho; Silva, Ricardo GonçalvesVisando identificar a influência do sistema de cultivo do milho (exclusivo e consorciado) e das aduba4aes mineral e vrganica na incidancia de alguns insetos, realizou- se um experimento em area de ensaio permanente, onde se estudam ha 14 ands os efeitos das adubações mineral e urganica continual sobre a produção de milho. O experimento foi conduzido em blocos casualirados, com quatro repetições, em esquema fatorial com tres doses de adubo mineral (zero, 250 kg de 4-j4-8 + 1Q0 kg de sulfato de amonio (SA) e 500 kg de 4-14-5 + 300 kg de SA) x dugs doses de composto organico (zero e 40 m^3/ha) x doll sistemas de cultivo do milho (exclusivo e consorciado com feijAo). A densidade populational de SpoiJoptera frugiperda, Diabrotica speciosa, Dalbulus maidis e do predador Dora luteipis foi avaliada quando o milho apresentava 4, 8 e 12 folhas completamente desenvolvidas. A maior densidade populational de Dalbu/us maidis foi obtida quando o milho se encontrava no estádio de 4 folhas completamente desenvolvidas, enquanto, no caso de Spodoplerafrugiperda, a maior população coincidiu com o estadio de S folhas completamente desenvolvidas. D aumento da densidade populational do predador Doru luteipis. cm ambos os sistemas de cultivo do milho, esteve associado a utilização de composto argauica. A alto densidade populacional do predador Doris luteipes, no edio de 8 folhas, roincidiu cam a major intensidade de ataque da Iagarta4o-cartucho.Item Diclidophlebia smithi (Hemiptera: Psyllidae), a potential biocontrol agent for Miconia calvescens in the Pacific: Population dynamics, climate-match, host-specificity, host-damage and natural enemies(Biological Control, 2013-07) Morais, Elisangela Gomes Fidelis de; Picanço, Marcelo Coutinho; Bourchier, Robert S.; Meira, Renata Maria Strozi Alves; Barreto, Robert Weingart; Lopes-Mattos, Karina Lucas BarbosaDiclidophlebia smithi (Hemiptera: Psyllidae) has been proposed as a candidate biological control agent for Miconia calvescens (Melastomataceae), a neotropical tree regarded as one of the worst threats to the rainforest ecosystems of several Pacific islands. Populations of D. smithi monitored over three years at three sites in the state of Minas Gerais, Brazil were found to peak during the cooler, drier months from April to July, with air temperatures as the factor most strongly correlated (negatively) with population density. A biologically significant match of climate conditions (+0.7 CMI, using CLIMEX regional matching) was found between the study region in Brazil and 3 of 9 weather stations in the potential release area of Hawaii. This result coupled with the wide variation in climatic conditions under which D. smithi populations have been found in Brazil suggest that D. smithi has good potential to establish in at least some regions of Hawaii. No significant predator, parasitoids or entomopathogens were found attacking D. smithi in its native range. No nymphs or adults of D. smithi were found on any plant belonging to a list of 102 species of 58 plant families growing in the vicinity of colonized M. calvescens individuals. Conversely, potted sentinel plants of the Hawaiian biotype of M. calvescens were readily colonized by D. smithi during an experimental six-month field exposure. Greenhouse no-choice tests with nine species of Melastomataceae also demonstrated that D. smithi has a host-range restricted to M. calvescens. A study of the morphological changes caused on tissues of M. calvescens by D. smithi showed that attack on leaves caused a collapse in the epidermis, cell disorganization and degeneration of the vascular system. This study confirms that D. smithi has significant potential as a biocontrol agent for M. calvescens.Item Dry stress decreases areas suitable for Neoleucinodes elegantalis (Lepidoptera: Crambidae) and affects its survival under climate predictions in South America(Ecological Informatics, 2018-07) Silva, Ricardo Siqueira da; Kumar, Lalit; Shabani, Farzin; Ribeiro, Arthur Vieira; Picanço, Marcelo CoutinhoProjections of climate change show some regions of the world getting warmer, colder, dryer or wetter. Consequently, the effects of climate change on insect pests can alter the threat to agricultural systems. As a result of changed climate, areas can become more or less suitable for insect pests. Neoleucinodes elegantalis is one of the major pests of solanaceous crops in South America. Host plants for N. elegantalis are widely present in South America, however, N. elegantalis is absent from many regions in South America. Hence, future climate effects on suitability for development and spread of N. elegantalis in South America should be investigated. Due to these reasons, we developed a model of the climate for N. elegantalis using CLIMEX software for South America using A2 Special Report on Emissions Scenarios (SRES) for 2030, 2050, 2070 and 2100 and using two models, CSIRO-Mk3.0 and MIROC-H. The results of both models indicate that areas in South America that are climatically suitable at the present time will become climatically unsuitable for N. elegantalis by 2100 as a consequence of progressive increase of dry stress. This was confirmed using developmental bioassays, where survival was lowest at low relative humidity levels. There are also altering areas that are currently unsuitable that become suitable in the future. These results are helpful in developing future strategies to take advantage of new opportunities in solanaceous crops in regions that may be unsuitable for N. elegantalis and provide important information for anticipated possible risks of infestation of N. elegantalis.Item Eficiência e seletividade de inseticidas para o manejo de mosca branca e inimigos naturais em melancia(Revista Ceres, 2007-02) Bacci, Leandro; Pereira, Eliseu José Guedes; Crespo, André Luiz Barreto; Picanço, Marcelo Coutinho; Coutinho, Darley Cabral; Sena, Maria Elisa deEste trabalho teve por objetivo estudar a toxicidade de inseticidas ao biótipo B da mosca branca Bemisia tabaci (Homoptera: Aleyrodidae) e a seletividade ao parasitóide Encarsia sp. (Hymenoptera: Aphelinidae) e ao predador Lasiochilus sp. (Heteroptera: Anthocoridae) em melancia. Inicialmente testou-se a toxicidade de duas dosagens dos inseticidas abamectina 18 CE, carbaril 850 PM, cartape 500 PM, clorpirifós 480 CE, deltametrina 25 CE, etiom 500 CE, fenitrotiom 500 CE, malatiom 500 CE e triclorfom 500 CE a B. tabaci. Posteriormente, realizou-se um bioensaio para testar a toxicidade, tolerância e seletividade de abamectina, cartape, etiom e fenitrotiom a Encarsia sp. e Lasiochilus sp. Os inseticidas foram empregados em concentrações que correspondem a 100% (dose) e 50% (subdose) da dosagem utilizada para o controle da mosca branca. Cartape e abamectina foram eficientes no controle desta praga, com mortalidades superiores a 80%. A mortalidade causada por cartape manteve-se elevada quando se utilizou a subdose. Já a alta mortalidade causada por abamectina decresceu quando se utilizou a metade da dose. O predador Lasiochilus sp. foi mais tolerante a dose e subdose de abamectina e a subdose de cartape do que parasitóide Encarsia sp. Abamectina foi seletivo em favor de Lasiochilus sp. nas duas dosagens utilizadas. Já cartape apresentou seletividade a este predador somente na subdose. Estes resultados irão auxiliar o manejo da mosca branca e de seus inimigos naturais na cultura da melancia.Item Fatores que afetam a localização de Bemisia argentifolii em folhas de couve comum(Revista Ceres, 2003-05-08) Galvan, Ederson Luis; Marquini, Flávio; Semeão, Altair Arlindo; Picanço, Marcelo CoutinhoEste trabalho objetivou estudar os faiares que influenciam a localização da mosca- branca (Bernisia argentifolii Bellows & Perring } (Homoptera: Aleyrodidae) em falhas de couve comum (Brassica oleracea var. acephala). Cada planta foi individualizada em gaiolas de madeira revestidas de organza, sendo colocados 104 adultos da mosca-branca por gaiola. Os tratamentos foram a posição normal e invertida de folhas de couve, com quatro repetições. As plantas foram expostas ao sol por seis horas e avaliou-se o número de insetos nas faces adaxial e abaxial das folhas. A mosca-branca prefere localizar-se na parte inferior das plantas de couve, para proteger-se dry calor e da dessecação pelo sol e vento, mas localizam-se também na face abaxial das folhas. Esse comportamento não representa estrições ao ataque desse inseto nessa face tias filhas de couve.Item Identificação e quantificação dos componentes de perdas de produção do tomateiro em ambiente protegido(Horticultura Brasileira, 2008-04-29) Loos, Rodolfo Araujo; Silva, Derly José Henriques da; Fontes, Paulo Cezar Rezende; Picanço, Marcelo CoutinhoProcurou-se identificar e quantificar os componentes de perdas de produção do tomateiro em ambiente protegido, no período de verão-outono, evidenciando o componente crítico e o fator-chave de perdas da cultura, mediante a utilização da tabela de vida das culturas. O trabalho foi realizado na Horta de Pesquisa da UFV, de janeiro a junho de 2001, sob delineamento de blocos casualizados, com dois tratamentos (cultivar Santa Clara I 5300 e híbrido Débora Plus) e cinco repetições. Durante o ciclo de cultivo, foram avaliados o número de plantas mortas e as causas de morte, o número de flores e frutos/planta. Nas colheitas, os frutos sadios foram contados, pesados e classificados, sendo identificadas as causas de perda dos frutos danificados. Não houve diferença significativa entre produtividades comerciais de 'Sta. Clara' (40,18 t/ha) e 'Débora Plus' (54,98 t/ha). A produtividade classificada entre frutos graúdos A ('Sta. Clara': 24,39 t/ha; 'Débora Plus': 32,32 t/ha) também não foram diferentes entre si. A produtividade de frutos médios extra ('Sta. Clara': 7,60 t/ha; 'Débora Plus': 10,77 t/ha) e a soma de frutos médios especiais com pequenos ('Sta. Clara': 8,19 t/ha; 'Débora Plus': 11,90 t/ha) foram baixas. Observou-se maior influência da perda de frutos (r = 0,89) (P<0,01) sobre as perdas totais sendo, consequentemente, frutos o componente crítico de perdas da cultura. Entre os vários fatores de perda dentro do componente crítico de produção, podridão apical foi o que mais influenciou as perdas totais (r = 0,97) (P<0,01), sendo considerado o fator-chave de perdas da cultura nessas condições.Item Induced responses of Coffea arabica to attack of Coccus viridis stimulate locomotion of the herbivore(Entomologia Experimentalis et Applicata, 2011-04-11) Fernandes, Flávio Lemes; Picanço, Marcelo Coutinho; Gontijo, Pablo Costa; Fernandes, Maria Elisa de Sena; Pereira, Eliseu José Guedes; Semeão, Altair ArlindoThe green scale, Coccus viridis (Green) (Hemiptera: Coccidae), is an insect pest of coffee and several other perennial cultivated plant species. We investigated changes in alkaloid and phenolic contents in coffee plants as a response to herbivory by this insect. Greenhouse‐grown, 11‐month‐old coffee plants were artificially infested with the coccid and compared with control, uninfested plants. Leaf samples were taken at 15, 30, 45, and 60 days after infestation, and high‐performance liquid chromatography was used to identify and quantify alkaloid and phenolic compounds induced by the coccids at each sampling date. Of the compounds investigated, caffeine was the main coffee alkaloid detected in fully developed leaves, and its concentration in infested plants was twice as high as in the control plants. The main coffee phenolics were caffeic and chlorogenic acid, and a significant increase in their concentrations occurred only in plants infested by C. viridis. A positive and significant relationship was found between alkaloid and phenolic concentrations and the infestation level by adults and nymphs of C. viridis. Caffeine and chlorogenic acid applied on coffee leaves stimulated the locomotory activity of the green scale, thus reducing their feeding compared to untreated leaves. This is the first study to show increased levels of coffee alkaloids and phenolics in response to herbivory by scale insects. The elevation of caffeine and chlorogenic acid levels in coffee leaves because of C. viridis infestation seems to affect this generalist insect by stimulating the locomotion of crawlers.Item Insecticidal activity of dienamides on cabbage caterpillar and beneficial insects(Química Nova, 2018-04) Lopes, Mayara Cristina; Alvarenga, Elson Santiago; Aguiar, Alex Ramos; Santos, Izailda Barbosa dos; Silva, Gerson Adriano; Arcanjo, Lucas de Paula; Picanço, Marcelo CoutinhoThe demand for new insecticides is increasing due to the appearance of insect populations that are resistant to currently used products. New insecticides should be efficient in controlling pests and present low toxicity to non-target organisms. Ascia monuste (Lepidoptera: Pieridae) is a destructive pest of cole vegetables, and the fire ant Solenopsis saevissima (Hymenoptera: Formicidae) is an important predator of these caterpillars in brassica crops. Tetragonisca angustula (Hymenoptera: Apidae) is very important in pollinating many plants and providing honey. Therefore, this study evaluated the toxicity of synthetic amides to A. monuste and its selectivity in favor of S. saevissima and T. angustula. The amides (2E,4E)-N-propylhexa-2,4-dienamide (3) and (2E, 4E)-N-butylhexa-2,4-dienamide (4) caused high (96 and 93%, respectively) and fast (48 h) mortality of A. monuste. The amides 3 and 4 were not harmful to the predator (mortality of 5.7% for amide 3 and 7.14% for amide 4) and were slightly harmful to the pollinator (mortality of 38.57% for amide 3 and 28.12% for amide 4). The amides 3 and 4 are promising, as insecticides, due to the high and rapid mortality of A. monuste with low and moderate toxicity to S. saevissima and T. angustula, respectively.Item Insecticide selectivity and behavioral response of the earwig Doru luteipes(Crop Protection, 2011-09-24) Campos, Mateus R.; Picanço, Marcelo Coutinho; Martins, Júlio Cláudio; Tomaz, Adriano Cirino; Guedes, Raul Narciso C.Insecticide lethal and sub-lethal effects on non-target species are a focus in pest management programs. However, such studies are usually centered in relatively few groups of natural enemies of insect pests. Earwigs, although insect pest predators of key importance in Neotropical maize fields, have received very little attention. The earwig Doru luteipes (Sccuder) (Dermaptera: Forficulidae) is one of the main predators of the fall armyworm Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae). Both species were subjected to toxicity and selectivity studies with the insecticides chlorantraniliprole, chlorfenapyr, chlorpyrifos, λ-cyhalothrin, deltamethrin, etofenprox, methomyl and spinosad. The behavioral locomotory response of D. luteipes to these compounds was also assessed. Concentration-response bioassays indicated very low potency of chlorantraniliprole (>550,000× less toxic), followed by spinosad (>3,500× less toxic) and etofenprox (>1,100× less toxic) as compared to chlorpyrifos, the most toxic insecticide studied against this earwig species. These same three compounds exhibited the highest selectivity when comparing the earwig with its prey, the fall armyworm. Time-response bioassays using the insecticide label rates recommended against the fall armyworm confirmed the high selectivity of chlorantraniliprole and etofenprox, in addition to deltamethrin and methomyl. Again chlorpyrifos exhibited the lowest levels of selectivity. Exposure of the earwig to insecticide-treated surfaces indicated that spinosad reduced the locomotory activity of the adults probably increasing their insecticide exposure, while they avoided chlorfenapyr-, etofenprox-, and chlorpyrifos-treated surfaces. Chlorantraniliprole and etofenprox seem the most promising compounds for use against S. frugiperda whilst preserving populations of D. luteipes.Item Low concentrations of glyphosate-based herbicide affects the development of chironomus xanthus(Water, Air, & Soil Pollution, 2017-10) Pereira, Renata Ramos; Picanço, Marcelo Coutinho; Ferreira-Junior, Diogenis F.; Sarmento, Renato Almeida; Saraiva, Althiéris de Souza; Pestana, João L. T.; Soares, Amadeu M. V. M.Glyphosate is an herbicide commonly used worldwide for weed control and generally applied as part of a formulated product, such as Roundup. Contamination of surface water by glyphosate-based herbicides can cause deleterious effects in organisms, mainly in aquatic systems near to intensive agricultural areas (e.g., transgenic soybean crops). Given the lack of toxicological information concerning effects of glyphosate-based herbicides on tropical aquatic ecosystems, we aimed to evaluate the lethal and sub-lethal effects of Roundup Original® on the dipteran Chironomus xanthus. The endpoints evaluated included survival, growth, and emergence. The results showed that the 48 h LC50 for glyphosate to C. xanthus was 251.5 mg a.e./L. Larval growth of C. xanthus was reduced under glyphosate exposure (LOEC for body length = 12.06 mg/L; LOEC for head capsule width = 0.49 mg/L). No effects were observed in terms of cumulative percentage of imagoes emergence. However, low concentrations of glyphosate caused delayed emergence of females (at 1.53 mg/L) and induced fast emergence of males (at 0.49 mg/L), compared to control treatment. The deleterious effects of environmental relevant concentrations of glyphosate (0.7 mg/L) observed in terms of C. xanthus growth and development suggest that glyphosate-based herbicides can have negative consequences for aquatic non-target invertebrates such as Chironomus. Multigerational assays are needed to assess the long term effects of glyphosate on C. xanthus populations. Finally, our study adds ecotoxicological data on the effects of glyphosate-based herbicides on tropical freshwater invertebrates.Item Mapping global risk levels of Bemisia tabaci in areas of suitability for open field tomato cultivation under current and future climates(Plos One, 2018) Ramos, Rodrigo Soares; Kumar, Lalit; Shabani, Farzin; Picanço, Marcelo CoutinhoThe whitefly, Bemisia tabaci, is a major threat to tomato Solanum lycopersicum and ranks as one of the world’s 100 most invasive pests. This is the first study of B. tabaci (Biotype B and Q) global distribution, focusing on risk levels of this invasive pest, in areas projected to be suitable for open field S. lycopersicum cultivation under climate change. This study aims to identify levels of risk of invasive B. tabaci for areas of suitability for open field S. lycopersicum cultivation for the present, 2050 and 2070 using MaxEnt and the Global Climate Model, HadGEM2_ES under RCP45. Our results show that 5% of areas optimal for open field S. lycopersicum cultivation are currently at high risk of B. tabaci. Among the optimal areas for S. lycopersicum, the projections for 2050 compared to the current time showed an extension of 180% in areas under high risk, and a shortening of 67 and 27% in areas under medium and low risk of B. tabaci, respectively, while projections for 2070 showed an extension of 164, and a shortening of 49 and 64% under high, medium and low risk, respectively. The basis of these projections is that predicted temperature increases could affect the pest, which has great adaptability to different climate conditions, but could also impose limitations on the growth of S. lycopersicum. These results may be used in designing strategies to prevent the introduction and establishment of B. tabaci for open-field tomato crops, and assist the implementation of pest management programs.
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