Actividad repelente e insecticida de cuatro aceites esenciales de plantas recolectadas en Chocó-Colombia contra Tribolium castaneum / Repellent and insecticidal activity of four essential oils from plants recolleted in Chocó-Colombia against Tribolium castaneum

This study aimed to determine the repellent and insecticidal activity of four essential oils (EOs) from plants collected in the Chocó rain forest, Colombia, against T. castaneum . Conventional hydrodistillation was used to obtain the EOs. The repellent and insecticidal activities were evaluated by the preference area and gas dispersion methods, espectively. Statistical differences (p<0.05) were determined by applying a student's t-test. EOs of Siparuna guianensis, S. conica, Piper marginatum, and Nectandra acutifolia showed excellent repellent properties as the main findings, highlighting S. conicaEO with 84% repellency (1-hµL/cm2), while P. marginatum showed to be bioactive to the dose of 500 µL/mL (72 h), inducing mortality of 100% of the exposed population. In conclusion, the results evidenced the repellent properties of the EOs evaluated against T. castaneum , which allows us to conclude that these plant species are potential natural sources producing bio-repellents that contribute to the integrated control of T. castaneum.

Se evaluaron cuatro aceites esenciales (AEs) de plantas recolectadas en la selva pluvial del Chocó, Colombia, para determinar su actividad repelente e insecticida contra T. castaneum. Los AEs fueron obtenidos por hidrodestilación convencional. Las actividades repelentes e insecticidas se evaluaron por los métodos de área de preferencia y dispersión de gas, respectivamente. Las diferencias significativas (p<0,05) fueron determinadas aplicando una prueba t de student. Los AEs de Siparuna guianensis, S. conica, Piper marginatum y Nectandra acutifolia mostraron excelentes propiedades repelentes, destacando el AE de S. conicacon un 84% de repelencia (1µL/cm2), mientras que el AE de P. marginatummostró ser bioactivo a la dosis de 500 µL/mL (72 h) al inducir la mortalidad del 100% de la población expuesta. Se concluye que estas especies de plantas son fuentes naturales potencialmente viables para la producción de biorepelentes que contribuyan en el control integrado de T. castaneum.

Volatile chemical composition of Piper sancti-felicis Trel essential oil and its biocidal action against Tribolium castaneum (Herbst)

This research assessed the fumigant activity of the essential oil from Piper sancti-felicis Trel and five of its components on the Tribolium castaneum (Herbst) biological model. Hydrodistillation was used for extraction of the essential oil, with separation and identification of the compounds through gas chromatography coupled to mass spectrometry (GC-MS). The fumigant was evaluated through gas dispersion on the T. castaneum. The majority compounds found in the EO were b-nerolidol (15.4%), 3-carene (14.9%), p-cymene (9.1%), spathulenol (8.2%), a-cubebene (6.2%) and calamenene (5.2%). Piper sancti-felicis displayed fumigant activity with a LC50 = 108.5 & 956;g L-1 air, and other individual monoterpenes tested such as & 945;-terpinolene (LC50 = 110.1 & 956;g L-1 air), p-cymene (LC50 = 120.3 & 956;g L-1 air), 3-carene (LC50 = 130.6 & 956;g L-1 air), (R) -limonene (CL50 = 189.6 & 956;g L-1 air), and a-pinene (LC50 = 213.1 & 956;g L-1 air), were significantly less toxic than methyl pyrimiphos used as a positive control, CL50 = 87.4 & 956;g L-1 air. The essential oil of P. sancti-felicis can be considered as a natural source of biocides.

Fumigant toxicity of some essential oils against Red Flour Beetles, Tribolium castaneum (Herbst) and its safety to mammals / Toxidade fumigante de alguns óleos essenciais contra besouros de farinha vermelha, Tribolium castaneum (Herbst) e sua segurança para mamíferos

Abstract Fumigant activities for three essential oils; Garlic oil (Allium sativum L); Chili pepper (Capsicum annuum L.) and Nigella (Nigella sativa L.) were assessed at different concentrations against the adult and 20-days old larval stages of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) in the laboratory. The accumulative mortality was observed at different exposure periods (3, 5 and 7 days). The residual effect of garlic oil that was the effective oil, on the treated wheat grains was evaluated with respect to histological changes in the liver, kidney, and stomach of rat fed on this treated wheat. The results showed that the mortality rates of treated stages increased with increasing the time of fumigation treatment. Moreover the highest essential oils toxicity at the Median lethal concentration (LC50) values for exposure periods (3, 5 and 7 days) to fumigation were (126, 53, and 47 mg/L air) for adult stage and were (79, 62, and 41 mg/L air) for larval stage, respectively in the case of Garlic oil treatment. While, the lowest essential oils effective was Nigella oil at the Median lethal concentration (LC50) values for exposure periods (3, 5 and 7 days) to fumigation were (3594, 629, and 335 mg/L air) for adult stage and were (1040, 416, and 227 mg/L air) for larval stage, respectively. The toxicity effect of various essential oils against adults and larvae of T. castaneum at the LC50at 7 days fumigation could be arranged in descending order as follows: Garlic oil, Chili pepper oil, and Nigella oil. The histological changes showed that the organs slightly affected at the fumigation for 3 days. It may be concluded that the garlic essential oil is the good effective fumigant to control T. castaneum in the stored products and it recommended that the fumigation period does not exceed 3 days. The garlic essential oil has the potential for applications in IPM programs for stored-grain pests because of its high volatility and fumigant activity and its safety.

Resumo Atividades fumigantes de três óleos essenciais - óleo de alho (Allium sativum L.); pimenta-malagueta (Capsicum annuum L.) e Nigella (Nigella sativa L.) - foram avaliadas em diferentes concentrações contra adultos e larvas de Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) com 20 dias de idade em laboratório. A mortalidade acumulada foi observada em diferentes períodos de exposição (3, 5 e 7 dias). O efeito residual do óleo de alho, ou seja, o óleo eficaz, nos grãos de trigo tratados foi avaliado em relação às alterações histológicas no fígado, rim e estômago de ratos alimentados com esse trigo tratado. Os resultados mostraram que as taxas de mortalidade dos estágios tratados cresceram com o aumento do tempo de exposição ao tratamento de fumigação. A maior toxidade dos óleos essenciais nos valores de Concentração Letal Média (CL50) para os períodos de exposição (3, 5 e 7 dias) à fumigação foi (126, 53 e 47 mg/L ar) para a fase adulta e (79, 62 e 41 mg/L ar) para a fase de larva, respectivamente no caso do tratamento com o óleo de alho, enquanto que o óleo essencial menos eficaze foi o óleo de Nigella, com valores de CL50 para os períodos de exposição (3, 5 e 7 dias) à fumigação (3594, 629 e 335 mg/L ar) para a fase adulta, e (1040, 416 e 227 mg/L ar) para a fase de larva, respectivamente. O efeito da toxidade de vários óleos essenciais contra adultos e larvas de T. castaneum em LC50 aos sete dias de fumigação pôde ser organizado em ordem decrescente, como segue: óleo de alho, óleo de pimenta e óleo de Nigella. As alterações histológicas mostraram que os órgãos foram levemente afetados na fumigação por três dias. Pode-se concluir que o óleo essencial de alho é um bom fumigante efetivo no controle de T. castaneum nos produtos armazenados, e recomendou-se que o período de fumigação não ultrapassasse três dias. O óleo essencial de alho tem potencial para aplicações em programas de Integrated Pests Management (IPM) para pragas de grãos armazenados, devido à sua alta volatilidade, atividade fumigante e respectiva segurança.

Verification of atmospheric plasma irradiation as an alternative control method for Tribolium castaneum (Herbst) / Verificação da irradiação plasmática atmosférica como método alternativo de controle para Tribolium castaneum (Herbst)

Abstract Radio frequency plasma, RF plasma, has been applied to a number of industrial applications. Laboratory experiments were conducted to determine the RF plasma potential in Tribolium castaneum (Herbst) control. Three treatment variables: (1) helium or argon plasmas; (2) two power levels (50 and 100 watt); and (3) different RF plasma exposure times (0, 20, 40, 60 and 90 seconds) were examined in this study. The susceptibility of T. castaneum to treatment varies as gas, power level, and the exposure time varies. A positive correlation was found between insect mortality percent in treating larvae as well as treated pupae and exposure time to RF plasma and also the power level of irradiation. The results revealed that no live insects were found after a 90 second, 100 watt helium RF plasma treatment. The survival percents of the adults were developed from treated larvae and treated pupae were significantly reduced by increasing of the exposure time or power level. Obtained data indicated that the treatment with RF plasma might be considered as an environmentally compatible or alternative supplement to the other control methods for stored product-pests management.

Resumo Plasma de radiofrequência, plasma de RF, tem sido empregado em diversas aplicações industriais. Experimentos de laboratório foram conduzidos para determinar o potencial de plasma de RF no controle de Tribolium castaneum (Herbst). Foram examinados nesse estudo três variáveis ​​de tratamento: (1) plasma de hélio ou argônio; (2) dois níveis de potência (50 e 100 watts); e (3) diferentes tempos de exposição ao plasma de RF (0, 20, 40, 60 e 90 segundos). A suscetibilidade do T. castaneum ao tratamento varia conforme o gás, o nível de energia e o tempo de exposição. Foi encontrada uma correlação positiva dentre a porcentagem de mortalidade de insetos no tratamento de larvas, bem como as pupas tratadas e o tempo de exposição ao plasma de RF, e também o nível de potência da irradiação. Os resultados revelaram que não foram encontrados insetos vivos após 90 segundos, com 100 watts de tratamento com plasmas de hélio e RF. As porcentagens de sobrevivência dos adultos foram desenvolvidas a partir de larvas tratadas, e as pupas tratadas foram significativamente reduzidas pelo aumento do tempo de exposição ou nível de potência. Os dados obtidos indicaram que o tratamento com plasma de RF pode ser considerado como um suplemento ambientalmente compatível ou alternativo aos outros métodos de controle para o manejo de produtos-pragas armazenados.

Repellent activity of essential oils extracted from five Artemisia species against Tribolium castaneum (Coleoptera: Tenebrionidae) / Actividad repelente de aceites esenciales extraídos de cinco especies de Artemisia contra Tribolium castaneum (Coleoptera: Tenebrionidae)

Artemisia genus (family Asteraceae) has been widely used as medicines and cosmetic. The chemical compositions of essential oils extracted from five Artemisia species (A. anethoides, A. giraldii, A. roxburghiana, A. rubripes and A. sacrorum) were analyzed and the repellent activities of five essential oils were investigated by testing percent repellency (PR) in petri dish against Tribolium castaneum. By GC-MS analysis, the common components of the five essential oils were eucalyptol (11.09%-50.05%), camphor (6.28%-33.10%), terpinen- 4-ol (2.46%-12.41%), ß-caryophyllene (0.63%-10.68%) and germacrene D (2.28%-10.01%). 3,3,6-trimethyl-1,4-heptadien-6-ol (11.72%), 2-isopropyl-5-methyl-3-cyclohexen-1-one (24.80%) and ß-farnesene (12.23%) were the characteristic compounds in essential oils of A. sacrorum, A. anethoides and A. rubripes respectively. The essential oils of five plants showed repellent activity against T. castaneum. The PR of others four essential oils were comparable with DEET expect for A. sacrorum. The results indicated that the essential oils of A. anethoides, A. giraldii, A. roxburghiana and A. rubripes had the potential to be developed as repellent for control of T. castaneum.

El género Artemisia (familia Asteraceae) ha sido ampliamente utilizado como medicamentos y cosméticos. Se analizaron las composiciones químicas de los aceites esenciales extraídos de cinco especies de Artemisia (A. anethoides, A. giraldii, A. roxburghiana, A. rubripes y A. sacrorum) y se investigaron las actividades repelentes de cinco aceites esenciales mediante la prueba de repelencia porcentual (PR) en placa de petri contra Tribolium castaneum. Por análisis GC-MS, los componentes comunes de los cinco aceites esenciales fueron eucaliptol (11,09% -50,05%), alcanfor (6,28% -33,10%), terpinen-4-ol (2,46% -12,41%), ß-cariofileno 0,63% -10,68%) y germacrén D (2,28% -10,01%). 3,3,6-trimetil-1,4-heptadien-6-ol (11,72%), 2-isopropil-5-metil-3-ciclohexen-1-ona (24,80%) y ß-farneseno (12,23%). Los compuestos característicos en los aceites esenciales de A. sacrorum, A. anethoides y A. rubripes respectivamente. Los aceites esenciales de cinco plantas mostraron actividad repelente contra T. castaneum. El PR de otros cuatro aceites esenciales eran comparables con DEET esperado para A. sacrorum. Los resultados indicaron que los aceites esenciales de A. anethoides, A. giraldii, A. roxburghiana y A. rubripes tienen el potencial de ser desarrollados como repelentes para el control de T. castaneum.

Volatile chemical composition and bioactivities from Colombian Kyllinga pumila Michx (Cyperaceae) essential oil / Composição química volátil e bioactividades do óleo essencial do colombiano Kyllinga pumila Michx (Cyperaceae)

The essential oil from the fresh leaves of Kyllinga pumila (Michx) was obtained by hydrodistillation and characterized by gas chromatography-mass spectrometry (GC-MS). Twenty-eight volatile compounds were identified, major constituents of the oil were Methyl E,E-10,11-epoxyfarnesoate (43.8%), ß-elemene (12.5%), Z-caryophyllene (11.3%), germacrene D (7.1%) and E-caryophyllene (5.6%). Repellent and fumigant activities of the oil against Tribolium castaneum Herbst (Coleoptera: Tenebrionidae), were done using the area preference method. Additionally, we studied their antioxidant and phytotoxic effects. Essential oils exhibited a dose- dependent repellent activity, with values 90% at the applied concentration (0.01%), for both two and four hour's exposure. Essential oil from K. pumila showed 92% mortality at 500 µL L-1 air against T. castaneum on 24 hours of exposure. The value LC50 was 153.4 µL L-1. With moderate selective phytotoxic effects on L. perenne root growth (±70% inhibition). Kyllinga pumila shows high antioxidant potential (91.5%), an effect that is comparable with ascorbic acid (92.9%) used as a standard. The results indicated that K. pumila essential oil could be a promising alternative to new natural antioxidants, repellents, and biocides.

O óleo essencial das folhas frescas de Kyllinga pumila Michx., foi obtido por hidrodestilação e caracterizado por cromatografia gasosa acoplada a espectrometria de massas (CG-EM). O constituinte majoritário do óleo foi Metil E,E-10,11-epoxifarnesoato (43,8%), ß-elemeno (12,5%), Z-caryophylleno (11,3%), germacreno D (7,1%), E-caryophylleno (5,6%). A atividade repelente e fumigante do óleo frente à Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) foi determinada pelo método da área de preferencia. Também, foi estudado os efeitos antiferrugens e fitotóxicos. Óleos essenciais exibiram uma atividade repelente dependente da dose, com valores de 90% na concentração aplicada (0,01%), tanto para duas e quatro horas de exposição. O óleo essencial de K. pumila mostrou mortalidade de 92% a 500 µL L-1 ar frente à T. castananeum, em 24 horas de exposição. O valor LC50 foi 153,4 µL L-1. Com efeitos fitotóxicos seletivos moderado sobre o crescimento da raíz de L. perenne (± 70% de inibição). Kyllinga pumila mostra um elevado potencial antioxidante (92%), um efeito que é comparável com ácido ascórbico (95%) usado como padrão. Os resultados indicaram que o óleo essencial K. pumila poderia ser uma alternativa promissora para novos antioxidantes, repelentes e biocidas naturais.

Atividade inseticida do óleo de Copaifera langsdorffii Desf. (copaiba) sobre Tribolium castaneum (Coleoptera: Tenebrionidae / Actividad insecticida de aceite de Copaifera langsdorffii Desf. (copaiba) sobre Tribolium castaneum (Coleoptera: Tenebrionidae / Insecticidal activity of Copaifera langsdorffii Desf. (copaiba) oil aga inst Tribolium castaneum (Coleoptera: Tenebrionidae

Introdução: utilizou-se o óleo de copaíba (Copaifera langsdorffii Desf) em duas formas de aplicação como alternativa de controle de Tribolium castaneum. Objetivo: avaliar o potencial tóxico do óleo de copaíba (C. langsdorffii) sobre adultos de Tribolium castaneum. Métodos: os bioensaios foram conduzidos no Laboratório de Análise de Sementes, da Universidade Federal de Campina Grande, Campina Grande, Paraíba, Brasil. Realizaram-se dois bioensaios: No primeiro, adultos de T. castaneum foram confinados em recipientes de acrílico (50 mL) com tampa, possuindo o óleo nas diluições de 0,0 (testemunha); 10; 30; 50; 70 e 90 por cento, aplicando-se 0,5 mL da diluição sobre um disco de papel filtro; No segundo experimento, os insetos foram confinados em recipientes de plástico (100 mL) com tampa, por onde o óleo foi levado para o interior desses, na forma de névoa, nas doses de 0,0 (testemunha); 0,5; 1,0; 1,5; 2,0 e 2,5 mL. Para os dois experimentos avaliou-se o número de insetos mortos após 24, 48 e 72 h, e determinou-se a DL 50 e DL90. Os bioensaios foram organizados em esquema fatorial 6 x 3. Resultados: em ambos os experimentos, o óleo de copaíba se mostrou eficiente para o controle de T. castaneum, com mortalidades de até 100 por cento por contato e 97,5 por cento por nebulização. Conclusão: o óleo de C. langsdorffii, por contato ou nebulização, é tóxico a T. castaneum(AU)

Introducción: en este trabajo se utilizó el aceite de copaiba (Copaifera langsdorffii Desf.) aplicado de dos formas distintas como alternativa de control do Tribolium castaneum. Objetivo: evaluar el potencial tóxico del aceite de C. langsdorffii aplicado en adultos de T. castaneum. Métodos: los bioensayos se realizaron en el Laboratorio de Análisis de Semillas, Universidad Federal de Campina Grande, Campina Grande, Paraíba, Brasil. Para alcanzar los objetivos se llevaran a cabo dos bioensayos: primero, los adultos de T. castaneum fueron confinados en contenedores de acrílico (50 mL) con tapa, contiendo el aceite en diluciones de 0.0 (control); 10; 30; 50; 70 y 90 por ciento, se aplicando 0,5 mL de la dilución en un disco de papel de filtro. En el segundo bioensayo, los insectos se colocaron en recipientes de plástico (100 mL) con tapa, por donde el aceite fue llevado a estos en la forma de niebla, en las dosis de 0.0 (control); 0,5; 1,0; 1.5; 2,0 y 2,5 mL. En ambos bioensayos se evaluó el número de insectos muertos después de 24, 48 y 72 h, y se determinó la DL50 y DL90. Los bioensayos fueron dispuestos en un factorial 6 x 3. Resultados: en ambos experimentos, el aceite de copaiba fue eficiente para el control de T. castaneum, con tasas de mortalidad de hasta el 100 por ciento, por contacto, y 97,5 por ciento por nebulización. Conclusión. el aceite de C. langsdorffii, por contacto o nebulización es tóxico para T. castaneum(AU)

Introduction. we used the copaiba oil (Copaifera langsdorffii Desf.) in two application forms as an alternative control Tribolium castaneum. Objective: the objective of this study was to evaluate the toxicity of copaiba oil (C. langsdorffii) on adults of T. castaneum. Methods: bioassays were conducted in the Laboratory of Seed Analysis, Federal University of Campina Grande, Campina Grande, Paraíba, Brazil. There were two bioassays: (1) Mortality by Contact and (2) Nebulization. At first, the adults of T. castaneum were kept in acrylic containers (50 mL) with a lid having oil dilutions of 0.0 (control), 10, 30, 50, 70 and 90 percent, applying 0.5 mL of the dilution on a filter paper disc. In the second experiment, the insects were placed in plastic containers (100 mL) with lid, from which the oil was smuggled into these in the form of mist, at doses of 0.0 (control), 0.5, 1.0, 1.5, 2.0 and 2.5 mL. For the two experiments evaluated, the number of dead insects after 24, 48 and 72 hours as well as LD50 and LD 90. Bioassays were organized into 6 x 3 factorial arrangement. Results: in both experiments, the copaiba oil proved being effective for the control of T. castaneum, with mortality rates of up to 100 percent due to 97.5 percent by nebulization. Conclusion: the oil of C. langsdorffii, by contact or misting, is toxic to T. castaneum(AU)

Repellent activity of Glycosmis plant extracts against two stored product insects / Actividad repelente de extractos de plantas Glycosmis contra dos insectos de productos almacenados

In the present study, the repellent activities of the leaf and/or stem crude extracts of Glycosmis lucida Wall. ex Huang, G. craibii var. glabra, G. craibii Tanaka, G. oligantha Huang, G. pentaphylla (Retz) Correa. and G. esquirolii (Levl.) Tanaka were analyzed by using assays on petri dishes against Tribolium castaneum and Liposcelis bostrychophila. The leaf and stem extracts of G. lucida, G. craibii var. glabra, G. craibii Tanaka, G. oligantha and G. esquirolii possessed significant repellent activities against T. castaneum, the same level repellent with the positive control, DEET. However, the extracts of G. pentaphylla, no repellency but some insect attractant was observed. Moreover, they also showed repellent activities against L. bostrychophila. These results indicate that extracts from G. lucida and G. oligantha leaf could be a source of novel repellent against insects.

En el presente estudio, las actividades repelentes de la hoja y/o tronco de los extractos crudos de Glycosmis lucida Wall. ex Huang, G. craibii var. glabra, G. craibii Tanaka, G. oligantha Huang, G. pentaphylla (Retz) Correa y G. esquirolii (Levl.) Tanaka se analizaron mediante el uso de ensayos en placas de Petri contra Tribolium castaneum y Liposcelis bostrychophila. Los extractos de las hojas y tallo de G. lucida, G. craibii var. glabra, G. craibii Tanaka, G. oligantha y G. esquirolii poseían actividades repelentes significativas contra T. castaneum, el mismo nivel repelente del control positivo, el DEET. Sin embargo, los extractos de G. pentaphylla, no se observó la repelencia pero sí actividad atrayente de insectos. Por otra parte, también se mostraron las actividades repelentes contra L. bostrychophila. Estos resultados indican que los extractos de hojas de G. lucida y G. oligantha podrían ser una fuente de repelente contra los insectos.

Potencial inseticida de óleos essenciais sobre Tribolium castaneum em milho armazenado / Insecticidal potential of essential oils on Tribolium castaneum in stored maize

RESUMO O presente trabalho teve como objetivo investigar o potencial inseticida de óleos essenciais de Croton heliotropiifolius, Croton pulegiodorus, Myracrodruon urundeuva e Ocimumbasilicum sobre adultos de Tribolium castaneumem milho armazenado. Para cada óleo foram realizados bioensaios de fumigação, repelência e o efeito sobre a taxa instantânea de crescimento (ri), em cinco concentrações (0; 5; 10; 15 e 20 μL). Os bioensaios foram conduzidos sob condições constantes de temperatura (28±2 ºC), umidade relativa (70±5%) e escoto fase de 24 horas. Nos testes de fumigação diferentes concentrações dos óleos foi aplicado em tiras de papel filtro presas na parte inferior da tampa da câmara de fumigação (1,5L), a qual continha 20 gramas de substrato alimentar e 10 insetos adultos de T. castaneum não sexados. A mortalidade dos insetos foi avaliada após 48 horas de exposição. Os testes de repelência foram efetuados em arenas compostas por dois frascos ligados a uma caixa central. Em um frasco foi depositado o substrato alimentar com diferentes concentrações do óleo essencial, e, no outro, foi depositado apenas alimento (testemunha). Dez insetos adultos foram liberados na caixa central, ficando expostos por 5 dias para avaliação da preferência. Nos bioensaios de fumigação observou-se atividade inseticida do óleo essencial de M. urundeuva sobre adultos de T. castaneum. Nos bioensaios de repelência, todos os óleos testados apresentaram efeito repelente. A emergência de T. castaneumreduziu entre 33 e 100% quando foram criados em pó de milho tratado com os óleos essenciais. Os óleos essenciais de C. pulegiodorus e O. basilicum ocasionaram redução do crescimento populacional de T. castaneum em grãos de milho tratados. Os óleos testados demonstraram ser uma alternativa eficiente de controle para o uso nos programas de manejo de T. castaneum em unidades armazenadoras.

ABSTRACT The current work aimed at to investigate the insecticide potential of essential oils of Croton heliotropiifolius, Croton pulegiodorus, Myracrodruon urundeuva and Ocimum basilicum on adults of Tribolium castaneum in stored maize. For each oil, it were performed fumigation tests, repellency and the effect on the instantaneous rate of increase (ri), in five concentrations (0; 5; 10; 15 e 20 μL). Bioassays were carried out under constant temperature conditions (28±2 °C), relative humidity (70±5%) and scot phase of 24 hours. In fumigation different concentrations of test oils were applied on filter paper strips attached on the bottom of the fumigation chamber cover (1.5 L), which contained 20 grams of food substrate and 10 unsexed adults of T. castaneum. The insect mortality was recorded after 48 hours of exposure. The repellency tests were performed in arenas composed of two pots connected to a central box. In a pot it was deposited feed substrate, with concentrations of the essential oil, in the other pot (control) it was deposited only food. Ten adult insects were released in the central box, being exposed for 5 days to evaluate the preference. In the fumigation tests, insecticide activity of the essential oil of M. urundeuva was observed on adults of T. castaneum. In the repellency tests, all the tested oils presented repellent effect. The emergency of T. castaneumreduced between 33% and 100% when they were in the powdered maize treated with the essential oils. Maize grains treated with C. pulegiodorus and O. basilicum essential oils caused a significant decrease in the populations of T. castaneum. The tested oils proved to be an efficient control alternative for the use in managing programs of T. castaneum in storing units.

Identification and characterization of the Sudanese Bacillus thuringiensis and related bacterial strains for their efficacy against Helicoverpa armigera and Tribolium castaneum.

Forty-four isolates of Bacillus thuringiensis like bacteria from various sources in different locations from Sudan were tested for their insecticidal activity. The toxicity of these isolates ranged from 6.6 to 70% to the neonates of cotton bollworm, Helicoverpa armigera at 10 ppm concentration. The most effective ones are Kb-29, St-6 and Wh-1 comparable with HD-1.  Toxicity of isolates to larvae of the red flour beetle, Tribolium castaneum ranged from 20 to 100%. Isolates St-2 and St-23 gave 100% larval mortality within 15 days of exposure and were at par with Ab-8, Ab-12, Kb-26, Kb-30, Om-4, Po-2, Po-5, Po-7, Sa-8 and Wh-5 and were also comparable with E. coli clone expressing Cry3 toxin. The most effective five isolates viz., Kb-29, St-2, St-6, St-23 and Wh-1 belonged to B. thuringiensis. The St-6 isolate, which also showed high toxicity to T. castaneum larvae, had cry1 genes along with coleopteran active cry28 genes, but not cry3 genes. Of the 25 isolates characterized with 16s DNA sequencing, seven belonged to Paenibacillus spp., one Lysinibacillus sphaericus, one Bacillus pumilus, four Bacillus spp., and rest 12 belonged to B. thuringiensis. Biochemical characterization in each species showed variation. The present study shows potential of some isolates like Kb-29, St-2, St-6, St-23 and Wh-1 as promising bioinsecticides.

Chemical composition and bioactivity of Piper auritum and P. multiplinervium essential oils against the red flour beetle, Tribolium castaneum (Herbst) / Composición química y bioactividad de los aceites esenciales de Piper auritum y P. multiplinervium contra el escarabajo rojo de la harina, Tribolium castaneum (Herbst)

Stored grain insects have shown resistance to synthetic insecticides, fact that has promoted the use of vegetable species for integrated pest management. Piper auritum and P. multiplinervium are two plants from the Piperaceae family present in the department of Chocó, Colombia, one of the most important hot spots of biodiversity in the world. This study was conducted to determine the repellent activity and toxicity of essential oils (EOs) isolated from these plants against Tribolium castaneum, using the area preference and contact toxicity methods, respectively. P. auritum EO presented greater repellency than P. multiplinervium, the first showed 100 percent lethality at minimum tested exposure period (24 h) whereas the second reached 16 percent at 72 h. EOs were analyzed by gas chromatography-mass spectrometry. P. auritum major components were safrole (93.2 percent) and miristicine (4.3 percent), whereas for P. multiplinervium were beta-elemene (9.0 percent), trans-beta-caryophyllene (5.3 percent) and caryophyllene oxide (4.1 percent). It is speculated that the repellent effect of P. auritum may be related to its safrole content, a known repellent. These results evidenced Piper species could be used for development of repellents against T. castaneum.

Los insectos de los granos almacenados han mostrado resistencia a los insecticidas sintéticos, hecho que ha promovido el uso de especies vegetales para el manejo integrado de plagas. Piper auritum y P. multiplinervium son dos plantas de la familia Piperaceae presentes en el departamento del Chocó, Colombia, uno de los puntos de biodiversidad más importantes del mundo. En este estudio fue determinada la actividad repelente y toxicidad de los aceites esenciales (AE) aislados de estas plantas contra Tribolium castaneum, utilizando el método de área de preferencia y toxicidad por contacto, respectivamente. El AE de P. auritum presentó mayor repelencia que el de P. multiplinervium, el primero mostró 100 percent de letalidad al menor tiempo de exposición (24 h), mientras que el segundo alcanzó el 16 percent a las 72 h. Los AEs fueron analizados por cromatografía de gases-espectrometría de masas. Los componentes principales de P. auritum fueron safrol (93.2 percent) y miristicina (4.3 percent), mientras que para P. multiplinervium fueron beta-elemene (9.0 percent), trans-beta-cariofileno (5.3 percent) y óxido de cariofileno (4.1 percent). Se cree que el efecto repelente de P. auritum puede estar relacionado con su contenido de safrol, un repelente conocido. Estos resultados evidencian que las especies de Piper podrían ser utilizadas para el desarrollo de repelentes contra T. castaneum.

Pesticidal and pest repellency activities of a plant derived triterpenoid 2α, 3ß, 21ß, 23, 28-penta hydroxyl 12-oleanene against Tribolium castaneum

BACKGROUND: Tribolium castaneum (Herbst) is a major pest of stored grain-based products, and cause severe damage to cereal grains throughout the world. The present investigation was aimed to determine the pesticidal and pest repellent activities of 2α,3ß,21ß,23,28-penta hydroxyl 12-oleanene against T. castaneum. The compound 2α,3ß,21ß,23,28-penta hydroxyl 12-oleanene is a triterpenoid which was isolated from the roots of Laportea crenulata Gaud. Surface film technique was used for pesticidal screening, whereas, pest repellency property of the triterpenoid was determined by filter paper disc method. RESULTS: At 24 hours of exposure duration, significant mortality records (80% and 86%) were observed at doses 0.88 and 1.77 mg/cm². No significant change in mortality records was observed when duration of exposure was increased up to 48 hours. The triterpenoid showed significant repellency activity at doses 0.47 and 0.94 mg/cm². CONCLUSION: These data suggest that the triterpenoid 2α,3ß,21ß,23,28-penta hydroxyl 12-oleanene possess both pesticidal and pest repellency activities against T. castaneum and can be used in controlling the pest of grain-based products.

Pesticidal and pest repellency activities of rhizomes of Drynaria quercifolia (J. Smith) against Tribolium castaneum (Herbst)

BACKGROUND: Tribolium castaneum (Herbst) is a harmful pest of stored grain and flour-based products in tropical and subtropical region. In the present study, rhizome of Drynaria quercifolia (J. Smith) was evaluated for pesticidal and pest repellency activities against T. castaneum, using surface film method and filter paper disc method, respectively. In addition, activity of the isolated compound 3,4-dihydroxybenzoic acid was evaluated against the pest. RESULTS: Chloroform soluble fraction of ethanol extract of rhizome of D. quercifolia showed significant pesticidal activity at doses 0.88 to 1.77 mg/cm² and significant pest repellency activity at doses 0.94 to 0.23 mg/cm². No pesticidal and pest repellency activity was found for petroleum ether, ethyl acetate and methanol soluble fractions of ethanol extract as well as for 3,4-dihydroxybenzoic acid. CONCLUSION: Considering our findings it can be concluded that chloroform soluble fraction of rhizome of D. quercifoliais useful in controlling T. castaneum of stored grain and flour-based products.

antifungal, cytotoxic, antitermite and insecticidal activities of zizyphus jujube

Plants are very useful, self-generating machines, producing a variety of useful bioactive products. Keeping in view this idea, the crude methanolic extract and various fractions of Zizyphus jujuba were screened for antifungal, cytotoxic, antitermite and insecticidal activities. Low activity was shown by the crude methanolic extract [12%], n-hexane [9%], chloroform [20%] and ethyl acetate [14%] fraction against Penicillium notatum. Low activity was shown by the ft-hexane fraction against Aspergillus niger [10%] and Trichoderma harzianum [13%] and inactive against Aspergillus flavus, Fusarium oxysporum and Rhizopus stolonifer. The CHC1[3] fraction exhibited low activity of 10% against F. oxysporum while showing no activity against the rest of the test fungi. All the test samples were inactive against Rhizopus stolonifer. The crude methanolic extract was highly cytotoxic [73.33%] at the concentration of 1000 [microg/ml] while the rest of the test samples were low in toxicity at the same concentration. The crude methanolic extract of Zizyphus jujuba showed significant antitermite activity against Heterotermes indicola, among the test samples. Against Tribolium castaneum, Rhizopertha dominica and Callosbruchus analis the insecticidal activity was determined. All the test samples except rc-hexane showed low activity [20%] against T. castaneum. The w-hexane fraction showed low activity [20%] against R. dominica while the rest of the fractions were inactive against it. Low activity of 40% and 20% was shown by the chloroform and "-hexane fraction respectively against C. analis. The results of the present study revealed that the plant could be as potent source of cytotoxic drugs

Dynamics of extinction in coupled populations of the flour beetle Tribolium castaneum

Neste estudo analisamos o efeito da migração sobre o tempo de persistência de populações acopladas de Tribolium em diferentes ambientes. Quatro tratamentos foram estabelecidos para comparar diferentes níveis de heterogeneidade ambiental, alto, moderado, baixo e nulo. Os níveis de heterogeneidade foram estabelecidos por meio de diferentes quantidades de alimento oferecidas a cada população. Para investigar como funciona a expansão de risco entre populações conectadas, um modelo estocástico para duas populações acopladas foi empregado. O tratamento estabelecido para analisar a alta heterogeneidade ambiental foi o que exibiu maior tempo de persistência, apesar da análise de sobrevivência não revelar diferença significativa entre os tratamentos. A magnitude da diferença nas taxas de crescimento entre as populações provavelmente está associada ao tempo de persistência populacional.

Insecticidal activity of the plant Phyllanthus amarus against Tribolium castaneum.

The plant Phyllanthus amarus is used as folk medicine since the year 1800 and has been established for its important medicinal properties particularly for liver ailments. The present communication explores the insecticidal activity of ethanolic extract of aerial and root parts of this plant against stored grain pest Tribolium castaneum. LC 50 values of ethanolic aerial part were 895.77, 473.91, 279.89 and 260.85 microg/cm2, while 512.62, 376.96, 248.88 and 209.79 microg/cm2 for ethanolic root part at the exposure of 3, 5, 7, 9 and 11 days respectively. Ethanolic root extract possessed significant insecticidal activity against T. castaneum.

Actividad de extractos crudos de plantas aromáticas sobre la supervivencia y desarrollo de Tribolium Castaneum Herbst / Activity of crude extracs from aromatic herbs against survival and development of Tribolium castaneum herbs

Se seleccionaron algunas especies de plantas aromáticas:Artemisa absinthium l, Ocimum basilicum l, Borago officinalis l, Lavanda spica l, mentha rutundifolia l, Origanum vulgare l,Urtica urens l, Rosmarinus oofficinalis l, Lippia alba Mill y Thymus vulgaris l y se evaluó la actividad biológica sobre Tribolium castaneum Herbs (Cooleoptera, Tenebrionidae) cepa CIPEIN. Se emplearon Extractos crudos metanólicos de cada plantas impregnando la dieta de larvas de primer estadío de T. castaneum a 5000 ppm. Se evaluó su efecto sobre el desarrollo y la mortalidad larval. Los resultados se sometieron a ANOVA, Test de comparaciones múltiples LSD y a análisis Probit (p<- 0.05). Se obtuvo efecto letal significativo con Lavandula spica l y Lippia alba Mill, y el efecto subletal con esta ùltima especie fue significativo.

Relación entre la actividad de esterasas y la resistencia a malatión en una cepa de Tribolium Castaneum / Relation activity from enterase and t.castaneum malathion resistant

Se estudiaron comparativamente las esterasas de las cepas de Tribolium castaneum ULP (suceptible) y ML (resistente a malatión). La actividad de esterasas que hidrolizan acetato de * y ß naftol presentes en homogenatos de T. castaneum fue mayor en la cepa susceptible ML, mientras que la actividad frente al acetato de tiofenilo fue similar en ambas cepas. La distribución subcelular de la actividad esterástica frente al PTA mostró diferencias en ambas cepas. En los homogenatos de insectos de la cepa susceptible se observó que a mayor velocidad de centrifugación el sobrenadante resultó considerablemente más activo en la hidrólisis de acetato de tiofenilo. Se supone que ese resultado se debe a la presencia de un inhibidor endógeno no dializable, de peso molecular tal que puede ser parcialmente precipitado a 10.000g y en mayor medida a 100.000g. Los zimogramas de esterasas no inhibibles por eserina separadas por electroforesis en gel de poliacrilamida y reveladas con * y ß naftilacetato, mostraron, en todos los casos, una única banda que fue clasificada como aril o acetil esterasa. Los resultados descriptos encuadran en la teoría de la aliesterasa mutada, postulada para casos de resistencia al malatión, descriptos en otas especies de insectos