Toxicological Stability of Ocimum basilicum Essential Oil and Its Major Components in the Control of Sitophilus zeamais.

Essential oils (EOs) are widely recognized as efficient and safe alternatives for controlling pest insects in foods. However, there is a lack of studies evaluating the toxicological stability of botanical insecticides in stored grains in order to establish criteria of use and ensure your efficiency. The objective of this work was to evaluate the toxicological stability of basil essential oil (O. basilicum) and its linalool and estragole components for Sitophilus zeamais (Motschulsky) adults in corn grains by fumigation. The identification of the chemical compounds of the essential oil was performed with a gas chromatograph coupled to a mass selective detector. Mortality of insects was assessed after 24 h exposure. After storage for six (EO) and two months (linalool and estragole) under different conditions of temperature (5, 20, and 35 °C) and light (with and without exposure to light), its toxicological stability was evaluated. Studies revealed that the essential oil of O. basilicum and its main components exhibited insecticidal potential against adults of S. zeamais. For greater toxicological stability, suitable storage conditions for them include absence of light and temperatures equal to or less than 20 °C.

Headspace Solid-Phase Microextraction: Validation of the Method and Determination of Allyl Isothiocyanate Persistence in Cowpea Beans.

Essential oils are widely recognized as an efficient and safe alternative for controlling pests in foods. However, a few studies have determined the persistence of these compounds in stored grains. The present study optimized and validated a fast and effective method for extraction and quantification of allyl isothiocyanate (AITC-the main component of mustard essential oil) residue in cowpea beans. It also investigated the persistence of this substance in the grains. The proposed method employs headspace solid-phase microextraction (HS-SPME) and gas chromatography with a flame ionization detector (GC/FID). For optimizing it, a central composite design (CCD) was used, where the best conditions for the extraction of the AITC were achieved using 15 min fiber exposure at 30 °C. The performance of the method was assessed by studying selectivity, linearity, limits of detection (LOD) and quantification (LOQ), precision, and accuracy. The LOD and LOQ for AITC were 0.11 and 0.33 µg kg-1, respectively. The determination coefficient (R 2) was above 0.99. The relative recovery rate ranged from 108.2 to 114.8%, with an interday coefficient of variation below 9%. After 36 h, no residue was detected in the samples, demonstrating that the AITC has low persistence and can be safely used as a bioinsecticide for grains.

Optimal Extraction of Ocimum basilicum Essential Oil by Association of Ultrasound and Hydrodistillation and Its Potential as a Biopesticide against a Major Stored Grains Pest.

The essential oil of basil (Ocimum basilicum) has significant biological activity against insect pests and can be extracted through various techniques. This work aimed to optimize and validate the extraction process of the essential oil of O. basilicum submitted to different drying temperatures of the leaves and extracted by the combination of a Clevenger method and ultrasound. The biological activity of the extracted oil under different conditions was evaluated for potential control of Sitophilus zeamais. The extraction method was optimized according to the sonication time by ultrasound (0, 8, 19, 31 and 38 min) and hydrodistillation (20, 30, 45, 60 and 70 min) and drying temperature (20, 30, 45, 60 and 70 °C). The bioactivity of the essential oil was assessed against adults of S. zeamais and the effects of each variable and its interactions on the mortality of the insects were evaluated. The best yield of essential oil was obtained with the longest sonication and hydrodistillation times and the lowest drying temperature of leaves. Higher toxicity of the essential oil against S. zeamais was obtained by the use of ultrasound for its extraction. The identification and the relative percentage of the compounds of the essential oil were performed with a gas chromatograph coupled to a mass selective detector. The performance of the method was assessed by studying selectivity, linearity, limits of detection (LOD) and quantification (LOQ), precision and accuracy. The LOD and LOQ values for linalool were 2.19 and 6.62 µg mL-1 and for estragole 2.001 and 6.063 µg mL-1, respectively. The coefficients of determination (R2) were >0.99. The average recoveries ranged between 71 and 106%, with coefficient of variation ≤6.4%.

Insecticidal activity of Vanillosmopsis arborea essential oil and of its major constituent α-bisabolol against Callosobruchus maculatus (Coleoptera: Chrysomelidae).

Vigna unguiculata, one of the most important legumes, mainly in underdeveloped countries, is susceptible to post-harvest losses in storage by Callosobruchus maculatus (Fabricius, 1775) (Coleoptera: Chrysomelidae). The work evaluated the toxicity, inhibition of oviposition, instantaneous rate of population growth (ri) and the development of fumigated C. maculatus with the essential oil of Vanillosmopsis arborea and its major constituent, α-bisabolol. The experimental units consisted of 0.8 L flasks treated with concentrations of 1.2-11.2 µL L-1of air of the essential oil of V. arborea or its major constituent applied to disks of filter paper. α-Bisabolol was quantified as 409.33 mL L-1 of the essential oil. The development rate of C. maculatus was evaluated by daily adult counts. Oviposition was evaluated at lethal concentrations (LC50, LC25, LC10 and LC1). The LC50 and LC95 of the essential oil of V. arborea and α-bisabolol were 5.23 and 12.97 µL L-1 of air and 2.47 and 8.82 µL L-1 of air, respectively. At some concentrations, the α-bisabolol was more toxic to males than to females of the insect. Increased concentrations of the essential oil reduced the ri, rate of development, oviposition, and number of eggs of C. maculatus and therefore have potential for pest control.

Lasioderma serricorne (Coleoptera: Anobiidae): First Report on Black Sesame (Sesamum indicum).

Insect pests may make food products and by-products unfit for human consumption. This study reports the occurrence of Lasioderma serricorne (Coleoptera: Anobiidae) in packaged seeds of black Sesamum indicum. An intact plastic pot of S. indicum seeds was purchased by a consumer in a supermarket in Divinópolis, Minas Gerais state, Brazil, in April 2014 and was kept at his home for 3 months. Two hundred adults of this insect (196 dead and 4 alive) were counted in the pot with the seeds, besides three live larvae. This insect fed on S. indicum seeds, making them unfit for consumption. L. serricorne feed on and reproduce in S. indicum seeds stored in plastic packaging.

Efeito do ensacamento sobre a incidência de moscas-das-frutas e na qualidade das goiabas / Effect of bagging on the incidence of fruit flies and in the quality of guavas

Com o objetivo de determinar o tamanho ideal dos frutos para serem ensacados e avaliar a eficiência de diferentes ensacamentos no controle de moscas-das-frutas, bem como sua correlação com a qualidade das goiabas do Cariri cearense, realizou-se esta pesquisa no Crato, Ceará, no período de 13 de outubro de 2011 a 16 de abril de 2012 em um pomar comercial de goiaba da variedade Paluma. Foram avaliados sacos de pipoca, papel manteiga, jornal, plástico microperfurado, TNT e a testemunha; e quatro grupos de diâmetro dos frutos: 1º grupo (2,0 a 3,0 cm), 2º grupo (3,1 a 4,0 cm), 3º grupo (4,1 a 5,0 cm) e 4º grupo (5,1 a 6,0 cm). Os frutos foram colhidos à medida que atingiam a maturação e após cada colheita eram levados ao Laboratório de Entomologia da Universidade Federal do Cariri, Campus do Crato, para avaliar o ataque das moscas-das-frutas e os parâmetros físico-químicos dos frutos. O ensacamento dos frutos é eficiente no controle das moscas-das-frutas independente do tipo de saco utilizado, recomendando-se ensacar quando as goiabas estiverem com diâmetro igual ou inferior a 2,0 cm. O jornal favorece o aumento do peso, comprimento e ºBrix quando os frutos são ensacados com diâmetros de 4,1 a 5,0 cm. Já para obter frutos com maiores diâmetros, recomenda-se ensacar com 5,1 a 6,0 cm de diâmetro.(AU)

This research aimed to determine the optimal size of guava fruits to be bagged, and to evaluate the efficiency of different bagging at the control of fruits flies, as well as their correlation with the fruit quality. The work was conducted in a commercial guava orchard of Paluma variety at the municipality of Crato, in Cariri region, Ceará, Brazil, from October 2011 until April 2012. Popcorn bags, parchment paper bags, newspaper bags, micropierced plastic bags, TNT and the control were tested in four groups of fruits diameters: first group (2.0 to 3.0 cm), second group (3.1 to 4.0 cm), third group (4.1 to 5.0 cm) and fourth group (5.1 to 6.0 cm). Fruits were collected when they became mature and after each collect they were transferred to the Laboratory of Entomology of the Federal University of Cariri in order to evaluate the fruit flies attacks and the physicochemical parameters of the fruits. Bagging the guava is effective to avoid attacks from fruit flies, regardless of the type of bag used. Moreover, one can recommend bagging the guava with diameter less than 2 cm. Fruits were heavier, larger in length and with better Brix degrees when bagged in newspaper bags, with diameters ranging from 4.1 to 5.0 cm. On the other hand, to obtain fruits with larger diameters, one can recommend bagging the fruits with 5.1 to 6.0 cm in diameter.(AU)

Urina humana como atraente natural de Anastrepha spp. (Diptera: Tephritidae) em pomar de goiaba (Psidium guajava L.) / Human urine used as a natural attractive of Anastrepha spp. (Diptera: Tephritidae) in guava (Psidium guajava) orchard

Objetivando avaliar a eficiência da urina humana como atraente alimentar no monitoramento e/ou controle de Anastrepha spp. em pomar de goiaba, foram realizadas três pesquisas em Barbalha, Ceará. Na primeira, de 16 de março a 16 de abril de 2012, foram utilizados suco de goiaba e urina pura de doadores com idades de 20, 25, 30, 35 e 40 anos. Na segunda, conduzida de 25 de abril a 10 de junho de 2013, foram utilizados suco de goiaba e urina de doador de 30 anos nas concentrações de 10, 30, 50, 70 e 100% e períodos de envelhecimento de 3,7, 14 e 21 dias. Já na terceira pesquisa, de 27 de junho a 04 de julho de 2013, foram testadas urina masculina, feminina e a mistura delas. Os atraentes foram instalados em armadilhas McPhail em blocos ao acaso, contendo 400 mL do atrativo. Semanalmente, as armadilhas foram examinadas e as moscas coletadas levadas ao laboratório de Entomologia da Universidade Federal do Cariri, Campus do Crato, para triagem e contagem. Foi verificado que os adultos de Anastrepha spp. têm preferência por urinas de doadores jovens. O tempo de exposição da urina humana no campo influencia na captura, tendo sido observado que aos sete dias de exposição houve aumento na captura de adultos de Anastrepha spp. A urina masculina é mais eficiente do que a feminina, tornando-a ineficiente quando ocorre a mistura. Portanto, ela pode substituir o suco de goiaba no manejo agroecológico de moscas-das-frutas em goiabeiras de pequeno produtor, pois, além de gratuito, é de fácil aquisição e aplicação.(AU)

Aiming to evaluate the efficiency of human urine in comparison to guava juice in monitoring and/or control of Anastrepha spp. in guava orchard, three research studies were conducted in Barbalha, Ceará, Brazil. The first one, from 16 March to 16 April 2012, using guava juice and pure urine donors aged 20, 25, 30, 35, and 40 years old. The second one was conducted from April 25 to June 10, 2013, using guava juice and urine of a 30 year old donor testing concentrations of 10, 30, 50, 70, and 100% human urine, with aging periods of 3, 7, 4, 14, and 21 days. The last research occurred from 27 June to 4 July 2013, and tested the influence of male and female urine, and both mixed. Five McPhail traps were installed in a randomized block design, using 400 mL of the attractive in each one.The traps were examined once a week, and the flies were collected and taken to the laboratory of entomology of the Universidade Federal do Crato, Crato campus, for screening and counting. The adults of Anastrepha spp. prefer for urine from young donors and those that are more concentrated. The aging of the human urine (seven days) increases the capture of adults of Anastrepha spp. The male urine is more efficient than females' urine, making it inefficient when mixing. Therefore, urine can substitute the guava juice in agroecologic management programs in small producers' guava orchards. It´s free, easy to acquire and to apply.(AU)