ABSTRACT
Abstract Insects' ethology is an important factor when it is desired to carry out pest management. This knowledge makes it possible to manipulate behavioral activities, repel, or attract insects according to needs and interests. The maize weevil Sitophilus zeamais (Mots., 1855) (Coleoptera: Curculionidae), one of the main stored grain pests, has been the target of studies of behavioral changes studies through natural substances due to its resistance to different insecticidal classes. Thus, this study aimed to evaluate the effect of sublethal concentrations of neem extract and copaiba oil on the locomotor behavior of S. zeamais. The behavioral characteristic considered were walking activity, the frequency of contact of insects with the treated grain mass, and the time spent for this behavior. The walking activity of the S. zeamais increased with exposure to Neem extract and Copaiba oil. In general, the Neem extract and Copaiba oil-induced more contact with grain mass than the control, suggesting an attractive effect on the insect, however more significant for the Neem oil. The insect's behavior was altered, presenting a specific path due to Copaiba oil and Neem extract stimuli. These results indicate that Copaiba oil and Neem extract can be a potential alternative for controlling S. zeamais on stored products since changes in this pests' behavior can reduce qualitative and quantitative grain damage. Thus, the development of products based on Copaiba oil and Neem extract may be helpful for storage pest management.
Resumo A etologia dos insetos é um fator importante quando se deseja relizar manejo de pragas. Através deste conhecimento, é possível manipular atividades comportamentais, repelir, ou atrair os insetos de acordo com as necessidades e interesses. O gorgulho do milho Sitophilus zeamais (Mots., 1855) (Coleoptera: Curculionidae), uma das principais pragas de grãos armazenados tem sido alvo de estudos de alterações comportamentais através de substâncias naturais devido à sua resistência a diferentes classes de insecticidas. Assim, este estudo teve como objetivo avaliar o efeito de concentrações subletais de extrato de neem e do óleo de copaíba sobre o comportamento de movimentação de S. zeamais. As características comportamentais consideradas foram: a atividade de caminhamento, a frequência do contato dos insetos com a massa de grãos tratada, e o tempo gasto para realização destes comportamentos. A atividade de caminhamento do S. zeamais aumentou quando os insetos foram expostos ao extrato de Neem e ao óleo de copaíba. Em geral, o extrato de Neem e o óleo de Copaíba induziram mais contato com a massa de grãos do que o controle, sugerindo um efeito atrativo sobre o inseto, contudo este efeito foi mais significativo para o óleo de Neem. O comportamento do inseto foi alterado, apresentando um caminhamento específico devido aos estímulos do óleo de copaíba e do extrato de Neem. Estes resultados indicam que o óleo de copaíba e o extrato de Neem podem ser alternativas potenciais para o controle do S. zeamais em produtos armazenados, uma vez que alterações no comportamento desta praga podem reduzir os danos qualitativos e quantitativos nos grãos. Assim, o desenvolvimento de produtos baseados no óleo de copaíba e no extrato de Neem pode ser útil para o manejo de pragas de armazenamento.
ABSTRACT
Conventional extraction of oil and azadirachtin, a botanical insecticide, from Azadirachta indica involves defatting the seeds and leaves using hexane followed by azadirachtin extraction with a polar solvent. In order to simplify the process while maintaining the yield we explored a binary extraction approach using Soxhlet extraction device and hexane and ethanol as non-polar and polar solvents at various ratios and extraction times. The highest oil and azadirachtin yields were obtained at 6 h extraction time using a 50:50 solvent mixture for both neem leaves (44.7 wt%, 720 mg(Aza)/kg(leaves)) and seeds (53.5 wt%, 1045 mg(Aza)/kg(seeds)), respectively.
Subject(s)
Azadirachta , Ethanol , Limonins , SolventsABSTRACT
This work investigated the insecticidal activity of Cashew Nut Shell Liquid (CNSL) extracted from the species Anacardium humile, a native plant in the Cerrado biome, against Aedes aegypti. A. humile fruits were collected and kept in a forced ventilation kiln at 40ºC for seven days for CNSL extraction. Mortality tests were performed on third stage larvae, pupae and adults. In addition, female oviposition behavior, egg viability, and the residual effect of the solution on 3rd stage larvae were observed. The CNSL was diluted in decreasing gradient concentrations to obtain the Lethal Concentration (LC). In oviposition LC99 was used for larvae. Residual effect and oviposition tests were performed with LC99, LC 50 and LC90 were respectively obtained, 6.63 and 11.23 ppm for larvae. No mortality was observed in adults. The residual effect of the CNSL was five days in LC99. A repellent effect of CNSL on the females was noted, with a significant reduction of egg numbers and a change in egg stratification patterns in the oviposition substrate. The larval hatching rate of the eggs exposed to the substrate moistened with CNSL was significantly lower when compared to the control. The results evidenced the insecticidal activity of A. humile CNSL, suggesting it as a promising product in the quest for new botanical insecticides.
Subject(s)
Insecticides , Vector Control of Diseases , GrasslandABSTRACT
ABSTRACT Extracts of the seeds of Tephrosia vogelii Hook. f. were studied in relation to its chemical composition and toxicity to the brown stink bug Euschistus heros (F.). The extracts were obtained in ethyl acetate and ethanol in the sequence according to the polar nature of the solvents. Extracts were sprayed in concentration of 1.0, 2.5, 5.0, 7.5 and 10% on third-instars nymphs and adults, and mortality was recorded. Presence two rotenoids in ethyl acetate was detected, with analyzed with gas chromatography-mass spectrometry (GC-MS). Crude fraction analyses confirmed the presence of these rotenoids (tephrosin - 2.71% in ethyl acetate and 3.66% in methanol; and deguelin - 10.46% in ethyl acetate and 1.22% in methanol) and three other rotenoids in small amounts. Eight days after applications, ethyl acetate caused more stink bugs mortality and on less time than ethanol extract, because great quantity of rotenoids, as polarity. Concentrations above to 1 and 2.5% of the ethyl acetate extracts caused mortality above 80% of the nymphs and adults of E. heros, respectively. Concentration were considered high, thus chemist analyzes demonstrated high rotenoids presence. In conclusion, seed T. vogelli extracts, rich in deguelin and tephrosin (3:1), cause mortality of E. heros, however, high concentration are necessary.
Subject(s)
Glycine max , Cimicidae , Tephrosia/chemistry , GlycineABSTRACT
Pequi fruit peels contain steroids, triterpenes, flavonoids, tannins, and saponins, compounds that are potentially useful for integrated pest management. As such, the aim of this study was to evaluate the insecticidal activity of aqueous extracts of pequi fruit peels on Spodoptera frugiperda. Field-grown corn plants of the cultivar 'Al Alvaré' were sprayed with extract concentrations of 0.8%, 2.5%, 5%, and 10% (v/v) 40 and 47 days after germination. The pequi peels were chopped, oven dried (65°C for 72 hours), and ground in a grinding mill. The resulting powder was used to prepare a base-line extract (10%), and the other concentrations evaluated were prepared by diluting this extract. The intensity of the damage caused by S. frugiperda caterpillars was evaluated 43, 46, 50, and 53 days after germination, using a visual scoring scale. Application of the extract decreased the amount of damage caused by the caterpillars. The 5% extract concentration was the most effective, while the 10% extract concentration showed evidence of phytotoxicity after the second spraying. These results suggest that the pequi extract is toxic to the S. frugiperda caterpillars and can be used for the management of this pest.(AU)
Nas cascas dos frutos de pequi já foram identificados esteroides, triterpenos, flavonoides, taninos e saponinas, substâncias promissoras no manejo integrado de pragas. Com base nesta informação, objetivou-se com este trabalho avaliar a ação inseticida de extratos aquosos das cascas dos frutos de pequi a Spodoptera frugiperda. O ensaio foi realizado em campo, utilizando sementes de milho do cultivar 'AL Alvaré' que aos 40 e 47 dias após a germinação foram pulverizadas com concentrações dos extratos de 0,8%, 2,5%, 5% e 10% (v/v). Os extratos foram preparados a partir de cascas dos frutos de pequi que, após picadas, foram secas em estufa (65°C, por 72 horas) e moídas em moinho de facas. Com o pó foi preparado um extrato padrão (10,0%). As demais concentrações foram obtidas a partir deste extrato. Foram avaliadas a intensidade das injúrias causadas pelas lagartas de S. frugiperda em plantas com 43, 46, 50 e 53 dias, utilizando uma escala visual de notas. As pulverizações dos extratos reduziram o número de injúrias provocadas pelas lagartas. A concentração de 5% foi a mais eficiente nesta redução e a de 10% causou fitotoxicidade após a segunda pulverização. O extrato pequi é tóxico às lagartas de S. frugiperda e pode ser utilizado no manejo desta praga.(AU)
Subject(s)
Pest Control/methods , Spodoptera , Zea maysABSTRACT
AbstractInsecticides from plants have been studied as an alternative in agricultural production and in vector control of human diseases. The use of botanical insecticides may cause mortality in different stages, slow growth, infertile adults and decrease in viability of insect eggs. This study aimed to analyze the insecticidal potential of ethanol extract of Baccharis dracunculifolia DC, on Spodoptera frugiperda Smith, 1797 (Noctuidae) and Aedes aegypti L., 1762 (Culicidae). The botanical material was collected and prepared on February 8th, 2011 on the Fazenda Escola Três Barras (20°33'37.44043" S - 54°32'10.3824" W), Campo Grande, MS. The ethanol extract was prepared from dried leaves obtained of adult plants in a vegetative state at the Chemistry Laboratory of Anhanguera University-Uniderp. The experiments of biological activities were conducted at the Entomology Laboratory of the Catholic University Don Bosco, in a controlled environment with an average temperature of 25 ºC and photoperiod 12 hr. Experiments with S. frugiperda were conducted from August to October 2014. The collection of A. aegypti eggs was made in January 2014 and the treatments were done from March 10th to 17th, 2014. In the development of S. frugiperda the extract caused effect on caterpillars subjected to treatment at one and 10 days. The larval stage proved to be longer at both ages and pupal weight reduced at 10 days, as well as increased mortality at one day, when incorporated concentration 0.2 % into diet. The variables studied were mortality, larval duration, pupal weight, number and viability of the eggs. The bioassay used A. aedes third instar, 25 larvae per concentration, at four replicates. Parameters analysed for sublethal doses were pupal and larval, mortality, length larval and young (larva + pupa) the ethanol extract at concentrations 0.5 mg.mL-1 and 0.25 mg.mL-1. The extract resulted in deleterious effect on the development of caterpillars undergoing treatment in larvae of one and 10 days of age, the larval stage stretching, lower pupal weight in caterpillars 10 days and higher mortality in the group with one day of life. It did not interfere with the viability of eggs. In the life cycle of A. aegypti, the extract of B. dracuncufolia at the studied concentrations caused delay in the development of larval and pupal stages, and inhibited the emergence of adults in 85 % and 70 %. In laboratory conditions it can be said that the ethanol extract of B. dracunculifolia has a potential insecticide effect for both species of insects.
ResumenLos insecticidas de plantas han sido estudiados como una alternativa en la producción agrícola y el control de vectores de enfermedades humanas. El uso de insecticidas botánicos puede causar mortalidad en diferentes etapas, crecimiento lento, adultos infértiles y disminución en la viabilidad de huevos de insectos. Este estudio tuvo como objetivo analizar el potencial insecticida del extracto de etanol de Baccharis dracunculifolia DC, Spodoptera frugiperda Smith, 1797 (Noctuidae) y Aedes aegypti L., 1762 (Culicidae). Se recogió el material botánico y preparó el 8 de febrero 2011 en la Hacienda Escola Tres Barras. (20°33'37.44043" S - 54°32'10.3824" W), Campo Grande, MS. El extracto de etanol se preparó a partir de hojas secas obtenidas de plantas adultas en estado vegetativo en el Laboratorio de Química de la Universidad Anhanguera -Uniderp.Los experimentos de actividades biológicas se llevaron a cabo en el Laboratorio de Entomología de la Universidad Católica Don Bosco, en un ambiente controlado con una temperatura media de 25 °C y fotoperiodo de 12 hr. Los experimentos con S. frugiperda se llevaron a cabo de agosto a octubre 2014. La colección de huevos de A. aegypti se hizo en enero 2014 y los tratamientos se realizaron del 10 al 17 marzo 2014. En el desarrollo de S. frugiperda el extracto causa efecto sobre orugas sometidas a tratamiento de uno y 10 días. La etapa larval resultó ser más larga en ambas edades y el peso de la pupa se redujo a los 10 días; también, hubo aumento de la mortalidad en larvas de un día, cuando se incorporó la concentración 0.2 % en la dieta. Las variables estudiadas fueron la mortalidad, la duración de las larvas, el peso de las pupas, y el número y viabilidad de los huevos. El bioensayo utilizó A. aedes en tercer instar, y 25 larvas por concentración, en cuatro repeticiones. Los parámetros analizados para las dosis sub-letal fueran las pupa y larva, mortalidad, duración de las larvas y jóvenes (+ larva pupa) en el extracto de etanol a concentraciones de 0.5 mg.mL-1 y 0.25 mg.mL-1. El extracto resultó en efecto perjudicial sobre el desarrollo de las orugas de uno y 10 días de edad, sometidas a los tratamientos, prolongación de la fase larvaria, menor peso de pupa en las orugas de 10 días y una mayor mortalidad en el grupo con un día de vida. No hubo interferencia con la viabilidad de los huevos. En el ciclo de vida de A. aegypti, el extracto de B. dracuncufolia en las concentraciones del estudio, causó retraso en el desarrollo de las etapas de larva y pupa, y se inhibió la emergencia de los adultos en un 85 % y el 70 %. En condiciones de laboratorio, se puede decir que el extracto de etanol de B. dracunculifolia tiene potencial insecticida para ambas especies de insectos.
ABSTRACT
Abstract: INTRODUCTION: Dengue fever is a viral disease transmitted by the Aedes aegypti Linn. (1792) (Diptera: Culicidae) mosquito, which is endemic in several regions of Brazil. Alternative methods for the control of the vector include botanical insecticides, which offer advantages such as lower environmental contamination levels and less likelihood of resistant populations. Thus, in this study, the ability of botanical insecticide formulations to inhibit the activity of the liver enzymes serum cholinesterase and malate dehydrogenase was evaluated. METHODS: Inhibition profiles were assessed using in vitro assays for cholinesterase and malate dehydrogenase activity and quantitated by ultraviolet-visible spectroscopy at 410nm to 340nm. RESULTS Insecticide products formulated from cashew nutshell liquid [A] and ricinoleic acid [B] showed cholinesterase activity levels of 6.26IU/mL and 6.61IU/mL, respectively, while the control level for cholinesterase was 5-12IU/mL. The products did not affect the level of 0.44IU/mL established for malate dehydrogenase, as the levels produced by [A] and [B] were 0.43IU/mL and 0.45IU/mL, respectively. CONCLUSIONS Our findings show that in vitro testing of the formulated products at concentrations lethal to A. aegypti did not affect the activity of cholinesterase and malate dehydrogenase, indicating the safety of these products.
Subject(s)
Humans , Animals , Ricinoleic Acids/pharmacology , Cholinesterase Inhibitors/pharmacology , Cholinesterases/drug effects , Anacardium/chemistry , Insecticides/pharmacology , Liver/enzymology , Malate Dehydrogenase/antagonists & inhibitors , Spectrophotometry, Ultraviolet , In Vitro Techniques , Ricinoleic Acids/isolation & purification , Aedes , Insect Vectors/drug effects , Insecticides/isolation & purificationABSTRACT
Abstract Gyropsylla spegazziniana (Paraguay tea ampul) is one of the most important pests of Paraguay tea plants, and prohibition of synthetic insecticide use for control of this pest has led to the search for alternative methods. This laboratory study aimed to compare different control strategies for G. spegazziniana, utilizing a commercial neem seed oil product. Paraguay tea seedlings were treated with neem oil solution both pre- and post-infestation with 5th instar nymphs. The systemic action of neem oil was also evaluated by treating plant soil with the neem oil solution, followed by transfer of the insects to plants 24 h post-treatment. Spray treatments were effective against the pest, especially post-infestation (80% mortality), demonstrating the potential of neem oil for control of the Paraguay tea ampul. No significant effects were observed with respect to systemic activity.
Resumo Gyropsylla spegazziniana (ampola da erva-mate) é uma das principais pragas da erva-mate, tanto em áreas de plantio como em viveiros. A proibição do uso de inseticidas para o controle de pragas da cultura tem levado à busca de alternativas. Este trabalho visou avaliar comparativamente, em laboratório, estratégias de aplicação de um produto comercial à base de óleo de nim sobre G. spegazziniana, em solução a 5%. Os testes foram realizados em mudas de erva-mate, tratadas pré e pós-infestação com ninfas de 5º instar do inseto, para avaliação de contato. Também, avaliou-se a ação sistêmica do óleo de nim, aplicando-se a solução do produto no solo da muda de erva-mate, seguido da transferência dos insetos após 24 h. Verificou-se que os tratamentos via pulverização foram eficientes contra a praga, principalmente na aplicação pós-infestação (80% de mortalidade), comprovando o potencial inseticida do óleo de nim contra a ampola-da-erva-mate em mudas. Entretanto, em relação à atividade sistêmica, não foram observados efeitos consideráveis sobre a praga.
Subject(s)
Animals , Glycerides/pharmacology , Hemiptera/growth & development , Hemiptera/drug effects , Insect Repellents/pharmacology , Nymph/drug effects , Paraguay , Soil , Tea , Terpenes/pharmacology , SeedlingsABSTRACT
A cochonilha-da-roseta, Planococcus citri (Risso, 1813) (Hemiptera: Pseudococcidae), constitui um problema fitossanitário na cultura do café. O controle mais usual dessa praga é o químico, o que pode acarretar, além de problemas socioambientais, a seleção de indivíduos resistentes. Com isso, torna-se necessário o controle alternativo. Dessa forma, o objetivo deste trabalho foi estudar, em condições de laboratório, o potencial inseticida de diferentes partes da planta de Jatropha curcas , em variadas concentrações, sobre P. citri . Discos de folhas de café conilon com 10 cochonilhas (ninfas e adultos) foram pulverizados direta e indiretamente com auxílio da torre de Potter, com pressão de 15 Lb/pol2, aplicando 6 mL de solução por repetição. Testaram-se sete concentrações do óleo e de extratos, tanto na aplicação direta quanto na indireta, com 10 repetições por tratamento, sendo avaliada a mortalidade em função do tempo. Todas as estruturas de pinhão-manso, em ambas as vias de aplicação, apresentaram índices de mortalidade satisfatórios de P. citri , alcançando 91,6% de mortalidade nas concentrações de 1,5, 2,0 e 3,0% do óleo na aplicação direta.(AU)
The Planococcus citri (Risso, 1813) (Hemiptera: Pseudococcidae) is a phytosanitary problem in the coffee's cultivation. The most used type of control for this pest is the chemical one, which leads to the selection of resistant individuals, as well as social and environmental problems. Therefore, it is necessary to control the alternative. Thus, this paper had the aim of studying the potential insecticide in different parts of the plant Jatropha curcas , in some concentrations, over the P. citri . Dices of leaf containing 10 P. citri (nymphs and adults) were directly and indirectly sprayed with the Potter Tower's assistance, on the pressure at 15 Lb/pol2, applying 6 mL of solution per repetition. Seven concentrations of oil and extracts were tested, and the mortality was evaluated in function of time. All physic nut's structures in both routes of administration showed satisfactory mortality P. citri , reaching 91.6% mortality at the concentrations of 1.5, 2.0 e 3.0% oil in the direct application.(AU)
Subject(s)
Coffee , Jatropha , Hemiptera , Pest ControlABSTRACT
Strawberry fields receive several pesticides spraying and residues in fruits are recurrent. Development and application of methods that avoid applying pesticides mostly during fructification period are imminent needs. Comparison of population of two-sppoted spider mite (TSSM) Tetranychus urticae Koch. in organic and mineral fertilized plants (as used by growers) and treated with alternative products were done. Plants were grown in vessels in a greenhouse infested with local population of TSSM. Extracts of Tephrosia voggeli (Hook), neem oil (Azadirachta indica A. Juss.), and lime sulfur were applied three times against TSSM in ten days intervals. Assessments were done three times after each spraying. Interaction between fertilization and spraying alternatives was also assessed but was not significant. TSSM population was about 44% lesser in organic fertilized plants than those in inorganic fertilized. T. voggeli extracts reduced in large amounts TSSM; neem oil reduced in some assessments and an intermediate reduction was found for sulfur lime. Organic fertilization and T. voggeli extracts are potential strategies to manage TSSM and additional studies are proposed to enable wide utilization.
Lavouras de morango recebem várias aplicações de agrotóxicos e resíduos nos frutos são recorrentes. O desenvolvimento e a aplicação de métodos de manejo que evitem a aplicação de pesticidas, principalmente durante o período de frutificação, é uma necessidade iminente. Compararam-se as populações do ácaro rajado Tetranychus urticae Koch. em plantas adubadas com fertilizantes orgânicos e minerais (como o usados por produtores) e tratadas com produtos alternativos. As plantas foram cultivadas em vasos, em casa de vegetação infestada de população local do ácaro. Extratos de Tephrosia voggelii (Hook), óleo de nim (Azadirachta indica A. Juss.) e calda sulfocálcica foram pulverizados três vezes em intervalos de 10 dias. As avaliações foram realizadas três vezes após cada pulverização. A interação entre a fertilização e produtos alternativos em pulverização foi também avaliada, mas não foi significativa. A população do ácaro foi cerca de 44% menor em plantas fertilizadas com fertilizante orgânico do que aquelas com fertilizante mineral. Extrato de T. voggelii reduziu em grande quantidade a população do ácaro; o óleo de nim reduziu em algumas avaliações e redução intermediária foi observada com calda sulfocálcica. Adubação orgânica e extrato de T. voggeli são estratégias potenciais para manejar a população de ácaros e estudos adicionais são propostos para permitir ampla utilização.
ABSTRACT
A Bemisia tuberculata (Bondar, 1923) é atualmente a principal praga da cultura da mandioca. Este trabalho descreve o efeito de diferentes concentrações do extrato CHCl3 das folhas de Anacardium humile, em relação à Bemisia tuberculata, em condições de laboratório, em plantas de mandioca, além da composição química deste extrato. O fracionamento do extrato CHCl3 forneceu os triterpenos ácidos: oleanólico, ursólico e betulínico. As estruturas foram determinadas com base nos dados espectrais (RMN-1D e 2D) e subsequente comparação com dados da literatura. O ácido anacárdico foi identificado no extrato CHCl3 por cromatografia líquida de alta eficiência (CLAE). O extrato CHCl3 causou efeito na mortalidade de ninfas de mosca branca B. tuberculata de 66,30 a 74,90% em todas as dosagens testadas (2; 0,8; 0,4 e 0,006%). A atividade inseticida do extrato CHCl3 de A. humile sobre as ninfas de mosca-branca sugere que os triterpenos isolados podem ser utilizados como modelo para o desenvolvimento de novos inseticidas para o controle deste inseto.
Bemisia tuberculata (Bondar, 1923) is the most important pest of cassava crops. This work describes the effect of different concentrations of CHCl3 extract from the leaves of Anacardium humile in relation to Bemisia tuberculata, under laboratory conditions, in cassava plants and chemical composition of this extract. Fractionation of the CHCl3 extract yielded the triterpene acids: oleanolic, ursolic and betulinic. Their structures were determined on the basis of spectral data (NMR-1D and 2D) and subsequent comparisons with the literature. Anacardic acid was identified in CHCl3 extract by high performance liquid chromatography (HPLC). CHCl3 extract caused mortality of whitefly nymphs of B. tuberculata from 66.30 to 74.90%, in doses tested. The insecticidal activity of CHCl3 extract of A. humile on the nymphs of the whitefly suggests that pentacyclic triterpenes and anacardic acid have potential insecticidal activity.
Subject(s)
Manihot , Anacardiaceae , Anacardium , Hemiptera , Chromatography, Liquid , InsecticidesABSTRACT
Aiming to contribute to the development of alternative control methods of the coffee leaf miner, Leucoptera coffeella (Guérin-Mèneville & Perrottet, 1842) (Lepidoptera: Lyonetiidae), a search for plants able to produce active substances against this insect was carried out, with species collected during different periods of time in the Alto Rio Grande region, (Lavras, Minas Gerais, Brazil). Coffee leaves containing L. coffeella mines were joined with 106 extracts from 77 plant species and, after 48 hours, the dead and alive caterpillars were counted. The extracts from Achillea millefolium, Citrus limon, Glechoma hederacea, Malva sylvestris, Mangifera indica, Mentha spicata, Mirabilis jalapa, Musa sapientum, Ocimum basiculum, Petiveria alliaceae, Porophyllum ruderale, Psidium guajava, Rosmarinus officinalis, Roupala montana, Sambucus nigra and Tropaeolum majus showed the highest mortality rates.
Visando contribuir para o desenvolvimento de métodos alternativos de controle do bicho-mineiro-do-cafeeiro, Leucoptera coffeella (Lepidoptera: Lyonetiidae), buscou-se selecionar plantas coletadas em diferentes épocas na região do Alto Rio Grande, (Lavras, Minas Gerais, Brasil) que contenham substâncias ativas contra este inseto. Folhas de cafeeiro com minas intactas de L. coffeella foram colocadas em contato com 106 extratos provenientes de 78 espécies vegetais e, após 48 horas, contaram-se as lagartas vivas e mortas. Os extratos de Achillea millefolium, Citrus limon, Glechoma hederacea, Malva sylvestris, Mangifera indica, Mentha spicata, Mirabilis jalapa, Musa sapientum, Ocimum basiculum, Petiveria alliaceae, Porophyllum ruderale, Psidium guajava, Rosmarinus officinalis, Roupala montana, Sambucus nigra e Tropaeolum majus, provocaram os maiores índices de mortalidade.
Subject(s)
Biological Products/adverse effects , Lepidoptera/immunology , Plant Extracts/analysisABSTRACT
Cupins de hábito subterrâneo e os agroquímicos usados para controlá-los causam significativos prejuízos no meio ambiente urbano. Em virtude disso elaborou-se o presente trabalho, cujo o objetivo foi avaliar o efeito de extratos diclorometano e metanólico de três espécies da família Meliaceae, Azadirachta indica (A. JUSS), Melia azedarach (L.) e Carapa guianenses (AUBL.) sobre Coptotermes gestroi (WASMANN). Para tanto foram realizados dois experimentos em condições laboratoriais. O primeiro avaliou a sobrevivência dos insetos frente a condições ótimas (presença de umidade e alimento) e adversas (ausência de umidade ou alimento, ou de ambos os elementos). A umidade demonstrou ser o fator limitante, reduzindo de forma significativa a sobrevivência dos insetos (P < 0,05), seguida da ausência de alimento. O segundo experimento avaliou o efeito de extratos orgânicos das três plantas sobre C. gestroi. O experimento contou com seis tratamentos, e três grupos testemunhas (diclorometano, metanol e água). Os extratos que mais afetaram os insetos foram os de A. indica. AIDic que reduziu em 17 dias o tempo de sobrevivência, apresentando mortalidade superior a 70% a partir do sétimo dia, AIMet apresentou resultados semelhantes. Os extratos de M. azedarach (MADic) também reduziram significativamente a sobrevivência dos insetos (P < 0,05). Observou-se um claro efeito residual do solvente extrator, principalmente do metanol.
Subterranean termites and pesticides used to control them cause significant losses in the urban environment.Because of this the present work was elaborated; whose the objective was to evaluate the dichloromethane and methanol extracts effects of three species of the Meliaceae family, Azadirachta indica (A. JUSS), Melia azedarach (L.) and Carapa guianenses (AUBL.) on Coptotermes gestroi (WASMANN). For this purpose two experiments were carried out under laboratory conditions. The first one evaluated the survival of the insects front the excellent conditions (presence of humidity and food) and adverse (absence of humidity or food, or the both elements). The humidity demonstrated to be the limitant factor, by significant reduction of insects survival (P < 0,05), followed by the food lack. The second experiment evaluated the effect of organic extracts of three plants on C. gestroi. The experiment had six treatments, most controls: dichloromethane, methanol and water, with 10 repetitions each. The extracts that had more affected on the insects survival time was A. indica. AIDic (A. indica dichloro extract) reduced in 17 days the survival time, with 70% superior mortality from the seventh day, AIMet (A. indica methanolic extract) presented similar result. The dichloromethane extract of M. azedarach (MADic) also reduced significantly the insects survival (P < 0,05). A residual effect of the solvent extractor, mainly of methanol was observed clearly.
Subject(s)
Azadirachta , Isoptera , Meliaceae , Melia azedarach , InsecticidesABSTRACT
Objetivou-se, com o presente trabalho, verificar o efeito do extrato metanólico de Coffea racemosa Lour., espécie silvestre de cafeeiro portadora de resistência a uma das principais pragas da cultura cafeeira, o bicho-mineiro. Inicialmente, o extrato metanólico das folhas de C. racemosa foi pulverizado em mudas de cafeeiro Coffea arabica cv. Catuaí, em casa-de-vegetação, as quais foram expostas a adultos de L. coffeella para o teste de oviposição com chance de escolha. Observou-se que as plantas tratadas foram menos preferidas para oviposição. A seguir, realizou-se o teste de efeito ovicida, no qual mudas de C. arabica contendo ovos do bicho-mineiro foram pulverizadas com o mesmo extrato. Os experimentos foram conduzidos em delineamento inteiramente casualizado com cinco repetições. Verificou-se redução significativa na eclosão de larvas, e segundo análise por microscopia eletrônica de varredura, os ovos não viáveis apresentaram anomalias nas superfícies externas. Entretanto, os adultos provenientes de ovos tratados não foram afetados na percentagem de emergência, razão sexual e oviposição. Os resultados obtidos demonstram que C. racemosa apresenta-se como uma alternativa promissora ao controle do bicho-mineiro, necessitando, no entanto, de novos estudos para isolamento e identificação das substâncias bioativas.
The objective of this study was to evaluate the effect of Coffea racemosa Lour. methanolic extract , a wild coffee specie that presents resistance against the coffee leaf-miner, a major pest of coffee crop. The methanol extract of C. racemosa leaves was sprayed on coffee seedlings, Coffea arabica cv. Catuaí, in greenhouse, which were exposed to adults of L. coffeella for oviposition in free choice test. Plants treated were less preferred for oviposition. An ovicidal assay was carried out by spraying the methanol extract on C. arabica seedlings containing L. coffeela eggs on their leaves. The experiments were conducted in a completely randomized design with five replicates. Larvae hatching out from treated eggs were significantly reduced by the extract and non viable eggs presented some anomalies on their external surfaces according to analyses by scanning electron microscopy. However, the adults derived from treated eggs did not have the percentage of emergence, sex ratio and oviposition affected by the treatment. The results show that C. racemosa presents as a promising alternative to control the coffee leaf-miner, being necessary new studies to isolate and caracterize the bioactive substances against this pest.
ABSTRACT
A utilização de inseticidas botânicos e bioinseticidas constitui uma alternativa promissora para o manejo de Spodoptera frugiperda (J.E. Smith, 1797), na cultura do milho. No presente trabalho, objetivou-se avaliar o efeito de formulações comerciais de nim e de Bacillus thuringiensis subsp. aizawai - Bta sobre esta praga em laboratório. Lagartas de S. frugiperda com 10 dias de idade foram alimentadas com folhas de milho submersas na calda dos inseticidas Neemseto®, Natuneem® e Xentari® (B. thuringiensis subsp. aizawai Bta) nas concentrações 2,5; 5,0; 7,5; 10 mL ou g/L e testemunha (água). Os efeitos dos inseticidas dependeram da concentração utilizada, pois provocaram mortalidade crescente das lagartas, alongaram o período larval e reduziram o peso larval. Em alguns casos, também, reduziram o peso das pupas, a viabilidade pupal e a longevidade de adultos. Lagartas com 0-24 h de idade foram mais susceptíveis às concentrações de Neemseto® e Xentari® a 5 e 10 mL ou g/L, em relação às com 10 dias de idade. Com o aumento da concentração, os efeitos sobre o peso das pupas e viabilidade pupal foram, também, maiores em lagartas com 0-24 h de idade.
The use of botanical and biological insecticides constitutes a promising alternative to control Spodoptera frugiperda on corn crop. Thus, the present work evaluated the effect of commercial formulations of neem (Natuneem® and Neemseto®) and Bacillus thuringiensis subsp. aizawai - Bta (Xentari®) on this pest under laboratory conditions. Newly hatched and 10 days old fall armyworm larvae were fed with corn leaves treated with the insecticides at concentration of 2.5, 5.0, 7.5, and 10 mL or g/mL and control (water). An increased effect of the insecticides was found as function of increasing concentration, causing higher larval mortality, longer larval period and lower larval weight. In some cases, reduction of pupa weight, pupa viability and longevity of adults were also verified. Newly hatched larvae (ca. 0-24 h old) were more susceptible to 5 and 10 mL or g/L of Neemseto® and Xentari® as compared with 10 days old larvae. With the increase of insecticide concentration, the effects on the pupa weight and pupa viability were also greater on larvae of 0-24h old.
ABSTRACT
Trichogramma pretiosum Riley and Trichogrammatoidea annulata De Santis are commonly found in avocado and persimmon orchards in northern Parana state. However, their abundance depends on whether insecticides are used or not to control the key lepidopteran pests Stenoma catenifer (Wals.) (Lepidoptera: Elachistidae) and Hypocala andremona (Stoll) (Lepidoptera: Noctuidae), respectively. The aim of this work was to evaluate the effects of an aqueous neem seed extract (ANSE) at 15, 3 and 1.5 percent, and of an emulsifiable concentrate neem oil (ECNO) at 2.5, 0.5 and 0.25 percent on lifetime parameters of these trichogrammatids as a way of testing the feasibility of integrating the biological and chemical control methods. Chemicals were applied on Anagasta kuehniella (Zeller) (Lepidoptera: Pyralidae) eggs before or after parasitization (one, three or five days). ANSE was more deleterious to both parasitoid species than ECNO, regardless of the concentration and the time of application. The chemicals acted on a concentration and time dependent manner. Treating the host with neem before parasitism was less deleterious to wasp emergence, especially for T. annulata. Pre-treatments (24h) of the host eggs with ECNO at concentrations varying from 0.5 percent to 0.25 percent did not affect T. pretiosum longevity, but 2.5 percent reduced T. annulata survival. Feeding wasps with honey mixed with 0.25 percent ECNO negatively affected T. annulata survival.
Subject(s)
Animals , Azadirachta , Glycerides/pharmacology , Hymenoptera/drug effects , Pest Control, Biological/methods , Plant Extracts/pharmacology , Terpenes/pharmacologyABSTRACT
A abundância e o potencial inseticida de Derris amazonica e a necessidade de controle de Cerotoma arcuatus Olivier (Coleoptera: Chrysomelidae) na cultura do feijão-caupi (Vigna unguiculata L. Walp) estimularam a realização desta pesquisa, que objetivou avaliar a ação inseticida do extrato de D. amazonica a adultos de C. arcuatus em condições de laboratório. Os bioensaios testaram as vias de intoxicação por ingestão de folhas contaminadas, contato com superfície contaminada e aplicação tópica, com delineamento experimental inteiramente casualizado, com quatro repetições. Os valores de mortalidade e consumo foliar dos insetos foram submetidos à análise de regressão, sendo utilizada a análise de Probit para determinação das CL50, da DL50 e dos TL50. O extrato de D. amazonica, contendo 3,7% de rotenona, foi tóxico para adultos de C. arcuatus via ingestão de folhas contaminadas (CL50=15,14 µL do extrato.mL-1 de água), superfície contaminada (CL50=0,45 µL do extrato.cm-2) e aplicação tópica (DL50=1,44 µL do extrato.g-1 do inseto). Mortalidades de adultos de C. arcuatus superiores a 80% e os menores tempos letais médios foram obtidos na concentração de 5% (v v-1) do extrato em todos os bioensaios. O consumo foliar de adultos de C. arcuatus foi inversamente proporcional a concentração do extrato quando expostos por via de ingestão foliar ou aplicação tópica, sendo inclusive observada inibição da alimentação dos indivíduos. O extrato de D. amazonica é tóxico para C. arcuatus e inibe a alimentação dos insetos a partir da concentração de 1% (v v-1).
The abundance and insecticidal potential of Derris amazonica in addition to need of controlling Cerotoma arcuatus for bean crop stimulated this research. The objective of this work was to evaluate insecticide action of the extract of D. amazonica to adults of C. arcuatus in laboratory conditions. The bioassays were carried out using three distend methodologies: leaf intake, contact in treated surface (filter paper) and topical application. A completed randomized experimental design was used with four replications. Mortality values and leaf consumption of the insects were subjected to regression analyses, being the Probit analyses used to determine of the i.e., LC50, LT50 and LD50. The extract of D. amazonica containing 3.7% of rotenone was toxic to adults C. arcuatus when exposed to treated leaves (LC50 = 15.14 µl.mL-1), treated surface (LC50 = 0.45 µl.cm-2) and subjected to topical exposure (LD50 = 1.44 µl.g-1). In all bioassays the adults mortality was higher than 80% with lower median lethal times obtained with 5% (v.v-1) concentrations of the extract. Leaf consumption by adults C. arcuatus was inversely proportional to the concentration of the extract when exposed by leaf intake or topical application, also being observed inhibition of feeding individuals. The extract of D. amazonica is toxic to C. arcuatus and inhibits the feeding of insects from the concentration of 1% (v v-1).
Subject(s)
Rotenone , Derris/chemistry , Vigna , Insecticides , Coleoptera , ToxicityABSTRACT
Insecticide plants are an important tool among the new alternatives for pest control in IPM systems because they reduce the use of synthetic insecticides, preserving human health and the environment. We investigated the effects of aqueous extracts of Melia azedarach leaves and Azadirachta indica seeds and three tomato genotypes, 'Santa Clara', 'IPA-5' - Solanum lycopersicum (= Lycopersicon esculentum Mill), and LA444-1 - S. peruvianum (= L. peruvianum), on the development, reproduction and longevity of the tomato pinworm Tuta absoluta (Meyrick), under laboratory conditions. The trials were set up in a completely randomized design, with nine treatments [three genotypes x two extracts (M. azedarach and A. indica) and control]. The replication consisted on five tubes, each with three newly hatched larvae, totalizing 90 individuals per treatment. The larvae were fed with tomato leaves treated with aqueous extracts at 0.1 percent concentration or distilled water (control) and daily observed until adults' emergence. Larval and pupal development and mortality, pupal weight, longevity and fecundity were evaluated. The accession LA444-1 negatively affected the development and reproduction of T. absoluta; the tomato pinworm had similar development and reproduction on 'IPA-5' and 'Santa Clara' (the susceptible control). The association of resistant tomato genotypes and extracts of M. azedarach leaves and neem seeds did not result in synergistic or antagonistic effects on T. absoluta.
Subject(s)
Animals , Azadirachta , Lepidoptera/drug effects , Solanum lycopersicum/genetics , Melia azedarach , Plant Extracts/pharmacology , Genotype , Lepidoptera/growth & development , Plant Leaves , Seeds , WaterABSTRACT
Aqueous solutions of neem oil and aqueous extracts of neem seeds and leaves were sprayed on coffee fruits for laboratory evaluation of their efficiency in reducing infestation of the coffee borer, Hypothenemus hampei (Ferrari), in multi-choice preference assays in laboratory. Neem oil and extracts reduced infestation of fruits in a dose-dependent manner, acting as a repellent. At 0.5 percent, 1 percent and 1.5 percent, the oil reduced fruit infestation by 30.2 percent, 42.5 percent (P > 0.05), and 58.6 percent (P < 0.05), respectively, as compared with the control. Seed extracts at 1 percent, 2 percent and 4 percent (w/v) reduced infestation by 30.9 percent, 38.3 percent (P > 0.05) and 70.2 percent (P < 0.05), respectively; seed extracts at 0.15 percent, 1.5 percent and 15 percent (w/v) reduced fruit infestation by 16.5 percent, 38.5 percent (P > 0.05) and 56.9 percent (P < 0.05), respectively. Spraying the emulsifiable oil at 1 percent on coffee fruits and adult borers was compared with spraying on fruits or adults only. Adult-only spraying caused low mortality (P > 0.05) and low reduction on the number of damaged fruits (P > 0.05). Fruit-only spraying significantly reduced insect survival rates and the number of damaged fruits (P < 0.05). However, spraying on adults and fruits caused the greatest reduction in adult survival (55.6 percent; P < 0.05) and in fruit infestation (78.7 percent; P < 0.05), probably due to insect mortality and neem oil repellence acting together.
Subject(s)
Animals , Coleoptera/physiology , Coffea/parasitology , Fruit/parasitology , Glycerides/pharmacology , Insect Repellents/pharmacology , Terpenes/pharmacology , Laboratories , Nebulizers and VaporizersABSTRACT
A lagarta-do-cartucho, Spodoptera frugiperda (Lepidoptera: Noctuidae), é considerada a principal praga das gramíneas, especialmente da cultura do milho, responsável pelo intenso uso de inseticidas nas áreas agrícolas, ocasionando aumento nos custos e preocupações ambientais. O objetivo deste trabalho foi avaliar o efeito de vinte extratos de plantas, sobre a mortalidade larval de S. frugiperda. Os extratos foram obtidos por meio da mistura das folhas ou raízes das plantas numa proporção de 1:10. A infusão foi obtida pela adição de água aquecida a 90º C e o macerado preparado com água a 4º C. Nos bioensaios foram utilizadas 60 lagartas de segundo ínstar, por tratamento, onde foram aplicados 100 ?L dos extratos vegetais e, na testemunha, água destilada. Os extratos vegetais foram avaliados por espectofotometria e SDS-PAGE. Dentre as vinte espécies testadas, 7 apresentaram mortalidade para lagartas de S. frugiperda. Petiveria alliacea. Malva silvestris. Bacharis genistelloides. Zengiber officinale. Artemisia verlotorum. Cymbopogon citratus e Ruta graveolens. As taxas de mortalidade provocadas por esses extratos devem estar relacionadas às substâncias que ainda não foram avaliadas e que deverão ser alvo de futuros estudos.
The armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), is considered the main pest of the maize crop, being responsible for the intense use of synthetic insecticide in agricultural areas and the consequent rise in costs and environmental concerns. The aim of this study was to evaluate the effect of 20 plant extracts on the larval mortality of S. frugiperda. Extracts were obtained through a mix of plant leaves or roots, in a 1:10 proportion. The infusion was obtained by the addition of hot water at 90ºC and the grinding was prepared with water at 4º C. Sixty second-instar caterpillars were used per treatment in the bioassays when 100 ?L of plant extracts were applied, while distilled water was applied in the control treatments. The plant extracts were assessed by spectrophotometry and SDS-PAGE. Of the 20 species tested, 7 showed mortality for caterpillars S. frugiperda. Petiveria alliacea. Malva sylvestris. Bacharis genistelloides,Zengiber officinale. Artemisia verlotorum,Cymbopogon citratus and Ruta graveolens. Mortality rates caused by these extracts must be related to substances that have not been evaluated and should be the target of future studies.