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Essential oils of aromatic plants represent an alternative to classical pest control with synthetic chemicals. They are especially promising for the alternative control of stored product pest insects. Here, we tested behavioral and electrophysiological responses of the stored product pest Tribolium confusum, to the essential oil of a Brazilian indigenous plant, Varronia globosa, collected in the Caatinga ecosystem. We analyzed the essential oil by GC-MS, tested the effects of the entire oil and its major components on the behavior of individual beetles in a four-way olfactometer, and investigated responses to these stimuli in electroantennogram recordings (EAG). We could identify 25 constituents in the essential oil of V. globosa, with anethole, caryophyllene and spathulenole as main components. The oil and its main component anethole had repellent effects already at low doses, whereas caryophyllene had only a repellent effect at a high dose. In addition, the essential oil abolished the attractive effect of the T. confusum aggregation pheromone. EAG recordings revealed dose-dependent responses to the individual components and increasing responses to the blend and even more to the entire oil. Our study reveals the potential of anethole and the essential oil of V. globosa in the management of stored product pests.

Aphids use an alarm pheromone, E-&beta, farnesene (EBF), to warn conspecifics of potential danger. The antennal sensitivity and behavioural escape responses to EBF can be influenced by different factors. In the pea aphid, Acyrthosiphon pisum, different biotypes are adapted to different legume species, and within each biotype, different genotypes exist, which can carry or not Hamiltonella defensa, a bacterial symbiont that can confer protection against natural enemies. We investigate here the influence of the aphid genotype and symbiotic status on the escape behaviour using a four-way olfactometer and antennal sensitivity for EBF using electroantennograms (EAGs). Whereas the investigated three genotypes from two biotypes showed significantly different escape and locomotor behaviours in the presence of certain EBF doses, the infection with H. defensa did not significantly modify the escape behaviour and only marginally influenced the locomotor behaviour at high doses of EBF. Dose-response curves of EAG amplitudes after stimulation with EBF differed significantly between aphid genotypes in correlation with behavioural differences, whereas antennal sensitivity to EBF did not change significantly as a function of the symbiotic status. The protective symbiont H. defensa does thus not modify the olfactory sensitivity to the alarm pheromone. How EBF sensitivity is modified between genotypes or biotypes remains to be investigated.

Foram avaliados os quatro componentes sintéticos identificados no feromônio sexual da broca-pequena-do-tomate, Neoleucinodes elegantalis Guenée (BPT): (E)-11-hexadecenol (E11-16:OH), (Z)-11-hexadecenol (Z11-16:OH), (E)-11-hexadecenal (E11-16:Al) e (E)-11-Acetato de hexadecenila (E11-16:OAc). Testes de campo foram realizados com armadilhas objetivando identificar o composto mais eficaz na captura de machos do inseto e determinar o efeito de concentrações do isômero Z11-16:OH, em mistura com o componente mais eficaz na captura de machos. Em laboratório, foram realizados testes eletrofisiológicos com eletroantenógrafo para monitorar as respostas da antena de machos de N. elegantalis a diferentes concentrações dos componentes. E11-16:OH, na concentração de 100 µg foi o mais eficaz entre os componentes testados do feromônio sexual da BPT. A adição de seu isômero, Z11-16:OH, reduziu a captura de insetos. Obteve-se resposta fisiológica (potencial de ação) a todos os componentes testados. Para E11-16:OH, a intensidade de despolarização da antena aumentou em relação direta com sua concentração, no entanto, para os demais componentes, os quimioreceptores foram sensíveis somente nas concentrações mais altas. Four synthetic components of the sexual pheromone identified from the small tomato borer Neoleucinodes elegantalis Guenée (BPT) were evaluated: (E)-11-hexadecenol (E11-16:OH), (Z)-11-hexadecenol (Z11-16:OH), (E)-11-hexadecenal (E11-16:Al) and (E)-11-hexadecenyl acetate (E11-16:OAc). Field tests were carried out with traps aiming at identifying the most effective component in the capture of N. elegantalis males, and determining the effect of different concentrations of the isomeric Z11-16:OH, in a mixture with the most effective component, in the capture of the males. In laboratory, electrophysiological tests were carried out with an electroantennograph to monitor the response of the antenna of N. elegantalis males to logarithmic concentrations of the four identified components. E11-16:OH, at the concentration of 100 µg, was the most effective among the tested components of the sexual pheromone of BPT. The isomer of this component, Z11-16:OH, was added and reduced insect capture. Physiological responses to all tested components were registered. E11-16:OH promoted depolarization of the antenna in straight relation with its concentration, while for the others components, the chemoreceptors have responded only to the higher concentrations.

Submitted by Mario BC (mario@bc.ufrpe.br) on 2019-05-16T13:32:22Z No. of bitstreams: 1 Ivonaldo Carlos da Silva Santos.pdf: 1420113 bytes, checksum: 24a2bdb802c7fb273f52bc898e284b09 (MD5) Made available in DSpace on 2019-05-16T13:32:22Z (GMT). No. of bitstreams: 1 Ivonaldo Carlos da Silva Santos.pdf: 1420113 bytes, checksum: 24a2bdb802c7fb273f52bc898e284b09 (MD5) Previous issue date: 2018-02-28 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES Physic nut Jatrophas curcas L. is a common culture in the Brazilian Northeast, and its productivity has been limited by the attack of the mite Tetranychus bastosi. The control of this mite is done with synthetic acaricides, while the use of plant extracts is an alternative method. The acaricidal potential of mesquite (Prosopis juliflora DC) and juazeiro (Z. joazeiro Mart.) leaf extracts on T. bastosi was evaluated. On chapter I, the CL50 e CL90 of juazeiro extract were estimated to be used with the mesquite extract in experimental tests. The extracts toxicity was evaluated in the concentrations of 0%, 5%, 10%, 15%, 20%, 25% e 30% on T. bastosi females in physic nut leaves arenas impregnated with these concentrations. After 48 hours, the number of dead individuals was counted.in each treatment. To evaluate the ovicide effect, 25 T. bastosi eggs were disposed in Physic nut leaves arenas, followed by the pulverization of the extract. Every 24 hours, the number of hatched eggs was observed, during ten days. The extracts effect on the T. bastosi females progeny exposed to the CL50 e CL90 of the extracts was also evaluated. 5 arenas containing 60 T. bastosi females were submitted to the application of the extracts. After 48 hours, 15 females/treatments who survived the extracts action were individualized and, on a daily basis, the number of eggs/female, the viability and the survival of the subsequent stages were counted. The lethal concentrations obtained for the juazeiro extract were CL50 = 11,87% (m/v) and CL90 = 54,96% (m/v). Both extracts in the tested concentrations reduced the viability of T. bastosi eggs, featuring the CL90. The T. bastosi females submitted to mesquite and juazeiro extracts presented a reduction on the viable eggs percentage, showing values next to 75%. There wasn’t any effect in the mite’s larval phase, but there was a reduction on at least 50% of the nymphs survival. On chapter II, the toxicity and repellency of CL50 e CL90 of the mesquite and juazeiro watery extracts on T. bastosi was analyzed. The toxicity was evaluated on females disposed in physic nut leaves discs arenas, impregnated in the extracts lethal concentrations (CL50 ou CL90). After 48 hours, the alive and dead individuals in each treatment were counted. For the repellency test, the phsic nut arenas were interconnected by a coverslip. One disc was treated with one of the extracts in the lethal concentrations, and the other with destilled water (witness). 10 adult female mites were released in the central area of each arena, and after 48 hours, the alive mites in each disc were counted. The mesquite and juazeiro leaves watery extracts in both concentrations (CL50 ou CL90) presented different levels of toxicity, varying from highly toxic to slightly toxic. They presented repellent effect, except the juazeiro extract in CL50, and control efficiency in CL90, in which T. bastosi mortality was over 80%, representing promisisng results for the control of the mite. O pinhão-manso Jatrophas curcas L é uma cultura comum no Nordeste Brasileiro, cuja produtividade vem sendo limitada pelo ataque do ácaro Tetranychus bastosi. O controle deste ácaro é feito com acaricidas sintéticos sem registro para a cultura, sendo o uso de extratos vegetais um método alternativo. Foi avaliado o potencial acaricida dos extratos aquosos de folhas de algarobeira (Prosopis juliflora DC) e juazeiro (Z. joazeiro Mart.) sobre T. bastosi. No capítulo I foram estimadas a CL50 e CL90 do extrato de juazeiro para serem utilizadas com o de algarobeira em testes experimentais. Avaliou-se a toxicidade do extrato nas concentrações de 0%, 5%, 10%, 15%, 20%, 25% e 30% sobre fêmeas de T. bastosi em arenas de folhas de pinhão-manso impregnadas com estas concentrações. Após 48 horas contabilizou-se o número de indivíduos mortos em cada tratamento. Para avaliação do efeito ovicida 25 ovos de T. bastosi foram dispostos em arenas foliares de pinhão-manso, procedendo-se em seguida a pulverização dos extratos. A cada 24 horas, observou-se o número de ovos eclodidos durante dez dias. Também foi avaliado o efeito dos extratos sobre a progênie de fêmeas de T. bastosi exposta as CL50 e CL90 dos extratos. Cinco arenas contendo 60 fêmeas de T. bastosi foram submetidas à aplicação dos extratos. Após 48 horas, 15 fêmeas/tratamento que sobreviveram à ação dos extratos foram individualizadas e, diariamente, contabilizou-se o número de ovos/fêmea, a viabilidade e a sobrevivência dos estágios subsequentes. As concentrações letais obtidas para o extrato de juazeiro foram: CL50 = 11,87% (m/v) e CL90 = 54,96% (m/v). Ambos os extratos nas concentrações testadas reduziram a viabilidade dos ovos de T. bastosi, com destaque para as CL90. Fêmeas de T. bastosi submetidas aos extratos de algarobeira e juazeiro apresentaram redução no percentual de ovos viáveis, apresentando valores próximos a 75%. Não houve efeito na fase larval do ácaro, mas houve redução em pelo menos 50% da sobrevivência de ninfas. No capítulo II foi analisada a toxicidade e repelência das CL50 e CL90 dos extratos aquosos de algarobeira e juazeiro sobre T. bastosi. A toxicidade foi avaliada sobre fêmeas dispostas em arenas de discos foliares de pinhão-manso impregnadas nas concentrações letais (CL50 ou CL90) dos extratos. Após 48 horas contabilizou-se o número de indivíduos vivos e mortos em cada tratamento. Para o teste de repelência, as arenas de pinhão-manso foram interligadas por uma lamínula, sendo um disco tratado com um dos extratos nas concentrações letais e outro com água destilada (testemunha). Foram liberadas 10 fêmeas adultas do ácaro na área central de cada arena, procedendo-se após 48 horas a contagem dos ácaros vivos em cada disco. Os extratos aquosos de folhas de algarobeira e juazeiro nas duas concentrações (CL50 e CL90) apresentaram índices de toxicidade variando de altamente tóxico a levemente tóxico. Apresentaram efeito repelente, exceto o extrato de juazeiro na CL50, e eficiência de controle nas CL90, cuja mortalidade de T. bastosi foi superior a 80%, representando assim resultados promissores para o controle do ácaro.

Submitted by (edna.saturno@ufrpe.br) on 2016-11-30T12:44:33Z No. of bitstreams: 1 Solange Maria de Franca.pdf: 508760 bytes, checksum: daf7b92b1d8c33b9a4b65c6ecc2d847b (MD5) Made available in DSpace on 2016-11-30T12:44:33Z (GMT). No. of bitstreams: 1 Solange Maria de Franca.pdf: 508760 bytes, checksum: daf7b92b1d8c33b9a4b65c6ecc2d847b (MD5) Previous issue date: 2009-02-02 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES Among the pests that attack tomato, to the tomato fruit borer, Neoleucinodes elegantalis (Guenée) (Lepidoptera: Crambidae), is responsible for significant losses in productivity. It’s control is usually done by excessive insecticide applications. Thus, researches with new tactics that aims to reduce pesticides use are essential to better manage this pest. The present study evaluated the ovicide effect, oviposition preference, food preference, threshold of food intake, and toxic effect of insecticides associated with attractive food sources, seeking the control of N. elegantalis. The LCs50 for N. elegantalis eggs varied from 0.029 to 4.19% according to the following sequence of decreasing toxicity: deltametrin > NeemPro > Natunem® > Neemseto®. According to the toxicity rate, deltametrin was 144 times more toxic than Neemseto ®. The highest and lowest deterrence was obtained for Natuneem® and deltametrin, respectively. Thus, sucrose, molasses, honey and orange juice were selected to determine the threshold concentrationcapable of stimulating feeding of N. elegantalis adults. Sucrose and honey were the most attractive food sources, regarding the number of lands, landing time, and feeding time of adults of N. elegantalis. In contrast, only sucrose showed a positive correlation among the tested concentrations, the landing time, and the feeding time of adults and males. The toxic effect of insecticides associated with honey 10% was also tested. The insecticides did not affect negativelythe attraction of N. elegantalis adults. Carbaryl, cartap, deltamethrin, fenpropatrina, indoxacarb, lambda-cyhalothrin, and lufenuron caused 100% mortality in males and females and adults of N. elegantalis, after 24h exposure, suggesting that they are promising for using in toxic baits. Dentre as pragas que infestam a cultura do tomateiro, destaca-se a broca-pequena, Neoleucinodes elegantalis (Guenée) (Lepidoptera: Crambidae), responsável por perdas significativas na produtividade. Seu controle é feito, comumente, com aplicações excessivas de inseticidas. Assim, pesquisas visando reduzir o uso de agrotóxicos são essenciais para o manejo mais adequado dessa praga. No presente trabalho avaliou-se o efeito ovicida, a preferência para a postura, a preferência alimentar, o limiar de ingestão e o efeito tóxico de inseticidas associados a atraentes, visando o controle de N. elegantalis. As concentrações letais (CL50s) dos inseticidas para ovos de N. elegantalis variaram de 0,029 a 4,19%, obedecendo à seguinte ordem decrescente de toxicidade: deltametrina > NeemPro > Natunem® > Neemseto®. De acordo com razão de toxicidade, deltametrina foi 144 vezes mais tóxico, em relação a Neemseto®. A maior e menor deterrência de oviposição de N. elegantalis foram obtidas, respectivamente, por Natuneem® edeltametrina. Foram selecionados os atraentes sacarose, melado, mel e suco de laranja, visando determinar o limiar de concentração capaz de estimular a alimentação de adultos de N. elegantalis. A sacarose e o mel apresentaram o melhor desempenho, em relação ao número e tempo de pouso e à alimentação de adultos de N. elegantalis. No entanto, apenas sacarose apresentou correlação positiva entre as concentrações testadas e o pouso e a alimentação deadultos e machos. O efeito tóxico de inseticidas associados ao mel a 10% também foi testado. Os inseticidas não afetaram negativamente a atração de adultos de N. elegantalis. Carbaril, cartape, deltametrina, fenpropatrina, indoxacarbe, lambda-cialotrina e lufenurom causaram 100% de mortalidade em adultos, machos e fêmeas de N. elegantalis, após 24 h de exposição, mostrando-se promissores para o uso em iscas tóxicas.