Comparison between highly toxic Bacillus thuringiensis serovar israelensis and Bacillus sphaericus strains against Lutzomyia longipalpis Lutz & Neiva 1912 (Diptera, Psychodidae, Phlebotominae) larvae

The effects of standardized concentrated spores and crystals suspensions of Bacillus thuringiensis serovar israelensis and Bacillus sphaericus against 3rd instar larvae of Lutzomyia longipalpis were recorded by means of qualitative bioassays. The experiments showed a significant difference on mortality and moulting delay between the entomopathogenic bacilli strains tested (p < 0.001). B. thuringiensis serovar israelensis LFB-Fiocruz 584 (a clone of IPS-82) was active against insect larvae assayed (62.5% ± 14.2 of mortality), however, no significant effect was observed with B. sphaericus LFBFiocruz 736 (a clone of strain 2362). The data reinforce the suggestion that B. thuringiensis serovar israelensis should be considered for further evaluation as a potential agent against L. longipalpis larvae. Key words: Bacillus, Lutzomyia longipalpis, control, bioassays.The effects of standardized concentrated spores and crystals suspensions of Bacillus thuringiensis serovar israelensis and Bacillus sphaericus against 3rd instar larvae of Lutzomyia longipalpis were recorded by means of qualitative bioassays. The experiments showed a significant difference on mortality and moulting delay between the entomopathogenic bacilli strains tested (p < 0.001). B. thuringiensis serovar israelensis LFB-Fiocruz 584 (a clone of IPS-82) was active against insect larvae assayed (62.5% ± 14.2 of mortality), however, no significant effect was observed with B. sphaericus LFBFiocruz 736 (a clone of strain 2362). The data reinforce the suggestion that B. thuringiensis serovar israelensis should be considered for further evaluation as a potential agent against L. longipalpis larvae. Key words: Bacillus, Lutzomyia longipalpis, control, bioassays

Comparison between highly toxic Bacillus thuringiensis serovar israelensis and Bacillus sphaericus strains against Lutzomyia longipalpis Lutz & Neiva 1912 (Diptera, Psychodidae, Phlebotominae) larvae

The effects of standardized concentrated spores and crystals suspensions of Bacillus thuringiensis serovar israelensis and Bacillus sphaericus against 3rd instar larvae of Lutzomyia longipalpis were recorded by means of qualitative bioassays. The experiments showed a significant difference on mortality and moulting delay between the entomopathogenic bacilli strains tested (p < 0.001). B. thuringiensis serovar israelensis LFB-Fiocruz 584 (a clone of IPS-82) was active against insect larvae assayed (62.5% ± 14.2 of mortality), however, no significant effect was observed with B. sphaericus LFBFiocruz 736 (a clone of strain 2362). The data reinforce the suggestion that B. thuringiensis serovar israelensis should be considered for further evaluation as a potential agent against L. longipalpis larvae. Key words: Bacillus, Lutzomyia longipalpis, control, bioassays.The effects of standardized concentrated spores and crystals suspensions of Bacillus thuringiensis serovar israelensis and Bacillus sphaericus against 3rd instar larvae of Lutzomyia longipalpis were recorded by means of qualitative bioassays. The experiments showed a significant difference on mortality and moulting delay between the entomopathogenic bacilli strains tested (p < 0.001). B. thuringiensis serovar israelensis LFB-Fiocruz 584 (a clone of IPS-82) was active against insect larvae assayed (62.5% ± 14.2 of mortality), however, no significant effect was observed with B. sphaericus LFBFiocruz 736 (a clone of strain 2362). The data reinforce the suggestion that B. thuringiensis serovar israelensis should be considered for further evaluation as a potential agent against L. longipalpis larvae. Key words: Bacillus, Lutzomyia longipalpis, control, bioassays

Tetranychus evansi se evade da defesa da planta

Ácaros fitófagos podem induzir ou suprimir as defesas da planta. A maioria das linhagens da espécie Tetranychus urticae induz as defesas reguladas pela rota do ácido jasmônico (JA) e ácido salicílico (SA) e essa indução tem sido correlacionada com a diminuição do desempenho reprodutivo de ácaros em plantas de tomate. Diferentemente, o ácaro vermelho Tetranychus evansi suprime as defesas reguladas pelas rotas do JA e SA e essa supressão se correlaciona com o aumento do desempenho dos ácaros de ambas as espécies. Isso significa que o desempenho reprodutivo de T. urticae e T. evansi é maior em folhas de tomate que foram previamente atacadas pelo ácaro supressor. Além disso, T. evansi produz uma densa teia sobre suas colônias, provavelmente para evitar competidores. Considerando que T. evansi suprime as defesas da planta, essa supressão pode ser vantajosa não apenas para os indivíduos de uma mesma espécie, mas também para outros herbívoros, principalmente quando essa supressão ocorre sistemicamente e em partes da planta não cobertas pela teia. Do mesmo modo, a indução de defesas pelo T. urticae pode afetar negativamente outros herbívoros. Portanto, nesta tese foi investigado se T. evansi suprime e T. urticae induz as defesas diretas de plantas de tomate apenas no local de ataque ou sistemicamente em partes não atacadas. Como resultado, foi encontrado que T. evansi manipula as defesas principalmente no seu local de ataque, porque o seu desempenho foi afetado apenas nos folíolos atacados e não foi afetado nos folíolos adjacentes. Portanto, sugere-se que estas duas estratégias (a produção da teia e a supressão das defesas de plantas apenas no seu local de ataque) podem evitar que outros herbívoros se beneficiem da supressão de defesa da planta promovida pelo T. evansi. Além disso, nesta tese foi também demonstrado que T. evansi manipula a indução de defesas diretas de outra planta, o feijão (Phaseolus vulgaris). Essa manipulação de defesas por T. evansi em plantas de feijão parece beneficiar T. urticae, pois o mesmo teve seu desempenho reprodutivo aumentado em folhas infestadas juntamente com o T. evansi. Devido às semelhanças desses resultados com resultados anteriores de supressão utilizando plantas de tomate, possivelmente, a capacidade de T. evansi de suprimir as defesas da planta é uma estratégia utilizada por esse herbívoro em várias plantas e não apenas no tomate e no feijão. Finalmente, tem sido sugerido que a supressão de defesas poderia beneficiar a planta e não o herbívoro. Isso, porque os inimigos naturais são na maioria das vezes sensíveis aos compostos produzidos pela planta como defesas diretas, e, portanto, a supressão dessas defesas pode beneficiar os inimigos naturais. Ou seja, é possível que a supressão das defesas por T. evansi e a indução por T. urticae afete os próprios herbívoros e seus inimigos naturais. Portanto, foi também investigado como a indução de defesas reguladas pela rota do JA ocasionada pelo ácaro T. urticae e a supressão pelo T. evansi podem afetar seu desempenho reprodutivo e o desempenho de seu ácaro predador, o Phytoseiulus longipes. Os resultados demonstram que o desempenho reprodutivo dessas duas espécies de ácaros e do ácaro predador foi afetado negativamente pelas defesas reguladas pela rota do JA. Além disso, os predadores preferem se alimentar de ovos provenientes de presas que se alimentaram em plantas sem o JA do que ovos provenientes de plantas com JA. Isso sugere que a supressão de defesas por T. evansi pode tornar seus ovos mais vulneráveis à predação. Portanto, ainda é uma questão em aberto, se a supressão das defesas de plantas por este ácaro é uma boa estratégia ou não. O objetivo desta tese foi obter maior clareza quanto aos custos e benefícios da supressão de defesa de plantas pelo T. evansi em comunidades seminaturais, conectando ecologia e biologia molecular. Reunir essas duas áreas de pesquisa tradicionalmente separadas dentro da comunidade científica visa fornecer novas perspectivas sobre como produzir e utilizar tomates geneticamente modificados e como manipular inimigos naturais, favorecendo assim o controle de pragas na agricultura.Fundação de Amparo a Pesquisa do Estado de Minas GeraisSpider mites are known to induce or suppress plant defences. For instance, most strains of Tetranychus urticae induce plant defences regulated by jasmonic acid (JA) and salicylic acid (SA) pathways and this response has been correlated with a reduction in their reproductive performance on tomato plants. In contrast, the red spider mite Tetranychus evansi suppresses the JA and SA defences and both spider mite species were found to perform much better on tomato leaves that were previously attacked by the suppressor mite. In addition, T. evansi spins a dense web over its colonies, which has been suggested as a strategy to hinder competitors. Given that T. evansi suppresses plant defences and that T. urticae induces it, the plant defences suppressed by the former, may be advantageous not only to conspecific mites, but also to other herbivores; especially if the plant response is not local, but systemic throughout the plant and if the plant parts attacked by T. evansi are not covered by the web. On the contrary, plant defences induced by the T. urticae may negatively affect other herbivores. Hence, I have investigated whether T. evansi and T. urticae affect induced tomato plant defences locally or systemically. The results show that T. evansi seems to manipulate plant defences mainly on its feeding site, because its oviposition performance was only positively affected at the site of its attack, but not in adjacent tomato leaflets. It suggests that these two strategies together (the spin of its web and the suppression of plant defences by T. evansi only at its feeding site) can confer advantages to avoid other herbivores of profiting from the suppression of plant defence. In addition, I also show that T. evansi manipulates induced plant defences in another plant, the common bean (Phaseolus vulgaris). Since T. urticae had a higher reproductive performance when sharing a leaf with T. evansi, the manipulation of plant defences by T. evansi on beans seems to benefit T. urticae. Due to the similarities of my results with previous reports of suppression using tomato plants, the T. evansi ability to suppress plant defences might be a widespread mechanism and employed on other plants and not only in tomato and beans. Finally, it has been suggested that suppression could even benefit the plant rather than the herbivore. Because natural enemies can be sensitive to compounds produced by the plant as direct plant defences, the natural enemies may benefit from suppression of these defences. Hence, suppression of plant defences by T. evansi and the induction by T. urticae may affect not only themselves, but also their natural enemies. Therefore, I also investigated how the induction of JA defences by the spider mite T. urticae and suppression by T. evansi can affect their reproductive performance and the performance of their predatory mite, Phytoseiulus longipes. My data showed that the reproductive performance of both spider mite species and the predatory mite was negatively affected by JA defences. In addition, we also show that predatory mites eat more prey eggs when these came from JA-undefended plants than from JA-defended plants. It suggests that defence suppression by T. evansi can backfire, since it makes it eggs more vulnerable to predation. Therefore, it is still an open question, whether the suppression of plant defences by this spider mite is the best strategy or not. In this thesis, I aimed to get a better insight in the costs and benefits of plant defence suppression by T. evansi within simple semi-natural communities linking ecology and molecular biology. These two fields of research traditionally work separately in the science. To bring them together can provide novel insights into how to use and breed tomato plants and how to manipulate the natural enemies to favour pest control in agriculture

Behavioral and chemical factors involved in the choice of genotypes of Solanum lycopersicon by Tuta absoluta females

Plantas superiores emitem uma grande variedade de compostos voláteis que podem ser percebidos por neurônios quimio-receptores especializados na antena do inseto. Fêmeas escolhem a planta hospedeira antes e durante a oviposição, evidenciando plantas resistentes e suscetíveis entre diferentes genótipos. Acredita-se que estímulos químicos produzidos pelas plantas de tomate devam regular suas relações interespecíficas com insetos-pragas, incluindo Tuta absoluta. Portanto, o objetivo deste estudo foi analisar, por meio de estudos de comportamento envolvendo técnicas de olfatometria em túnel de vento, identificação dos voláteis de tomate mediante cromatografia gasosa, e testes de oviposição, os mecanismos envolvidos na localização e escolha de plantas resistentes e suscetíveis por T. Absoluta. Para a realização deste estudo foram cultivados em casa de vegetação, plantas de cinco genótipos de Solanum lycopersicon: quatro subamostras do Banco de Germoplasma de Hortaliças da UFV (BGH-674, BGH-1497, BGH-1708, BGH-489) e a variedade Santa Clara. Em túnel de vento, foi avaliada a resposta de fêmeas acasaladas de T. absoluta a estes genótipos. Após essa análise inicial, verificou-se a presença de sete compostos químicos e sua provável influência na atratividade para as fêmeas. Considerando isso, a abundância relativa dos terpenos total variou entre os genótipos (p=0.0153) e foi negativamente relacionada com atratividade para as fêmeas. Os experimentos de oviposição tiveram a finalidade de avaliar se fêmeas de T. absoluta seriam capazes de discriminar locais de oviposição e, portanto, realizar uma oviposição diferenciada entre os genótipos. Para isso, sempre foi confinada apenas uma fêmea acasalada dentro de cada gaiola, sendo realizados três tipos de experimentos de oviposição. O primeiro oferecendo oportunidade de escolha entre todos os genótipos, colocando todos eles dentro de uma mesma gaiola, o segundo, ao contrário, individualizando cada genótipo, sem proporcionar chance de escolha e o último contrastando dois desses genótipos (um resistente e o outro suscetível). Após 24 horas contou-se o número de ovos colocados pelas fêmeas. No entanto, observou-se que para o primeiro experimento (p=0,924), o número de ovos não foi afetado pelo genótipo. No entanto, no segundo, essa diferença demonstrou-se marginalmente significativa (p=0,06) e no terceiro, apenas para o contraste BGH-674/Santa Clara o número de ovos ovipositados foi maior na variedade Santa Clara (p=0,025). Finalmente, tentando estabelecer uma relação entre os resultados de localização e oviposição, pode-se sugerir que os compostos voláteis são mais importantes do que as características morfológicas da folha, que parecem ter exercido uma menor in urgência na decisão de oviposição dessas fêmeas. Sendo assim, as sub amostras BGH-1497, BGH-674 e BGH-1708 foram consideradas resistentes por antixenose e a sua utilização como ferramenta na seleção de plantas hospedeiras e no monitoramento de pragas demonstra-se promissora.Higher plants release a wide variety of volatile compounds which are perceived by specialized neurons chemo-receptor in the insect antenna. Females choose host plants before and during oviposition showing susceptible and resistant plants between diferent genotypes. We believe that chemical stimuli produced by tomato plants should regulate, their interspecific relationship with pest insects, including Tuta absoluta. Therefore, the objective of this study was to carry out by behaviour studies involving olfatometry tecniques in wind tunnel and chemical identification of plants volatiles in gas cromatography and ovipositions tests, the mechanisms involved in the selection of susceptible and resistant plants by T. absoluta. To carry out this study, were grown in a greenhouse five genotypes of Solanum lycopersicon: four subsamples of Vegetable Germplasm Bank of the UFV (BGH-674, BGH-1497, BGH- 1708, BGH-489) and the variety Santa Clara. In the wind tunnel, the response of mated females of T. absoluta to this diferent genotypes was studied. After this first analysis, was examined the presence of seven chemical compounds and their likely influence on the attractiveness to females. Considering this, the relative abundance of total terpenes varied among genotypes (p=0.0153) and was negatively related to attractiveness to females. The oviposition test had the aim to assess whether females of T. absoluta would be able to discriminate oviposition sites, and thus accomplish diferent oviposition between the genotypes. For this, only a mated female was confined into every cage and were made three types of choice test. The first offering the opportunity to choose between all genotypes, puting them within a cage; the second, individualizing each genotype in small cages with no chance to choose and the third, contrasting two genotypes (one resistant and one susceptible). After 24 hours the number of eggs deposited by females were counted. However, it was observed that for the first experiment (p=0.924), the number of eggs was not affected by genotype. In the second one, this diference was marginally significant (p=0.06) and in the third experiment, only for the contrast Santa Clara/BGH-674 the number of eggs oviposited were bigger in the variety Santa Clara (p=0.025). Finally, trying to establish a link between localization and oviposition it could be suggested that volatile compounds are more important than morphological characteristics of the leaf that would have had little influence on oviposition decision of females. Considering these results, the subsamples BGH-1497, BGH-674 and BGH-1708 were considered resistant to antixenosis and its use as a tool in the selection of host plants and pest monitoring shows to be interesting.Fundação de Amparo a Pesquisa do Estado de Minas Gerai

Implementation of a Brazilian Cardioprotective Nutritional (BALANCE) Program for improvement on quality of diet and secondary prevention of cardiovascular events: A randomized, multicenter trial

Background: Appropriate dietary recommendations represent a key part of secondary prevention in cardiovascular disease (CVD). We evaluated the effectiveness of the implementation of a nutritional program on quality of diet, cardiovascular events, and death in patients with established CVD. Methods: In this open-label, multicenter trial conducted in 35 sites in Brazil, we randomly assigned (1:1) patients aged 45 years or older to receive either the BALANCE Program (experimental group) or conventional nutrition advice (control group). The BALANCE Program included a unique nutritional education strategy to implement recommendations from guidelines, adapted to the use of affordable and regional foods. Adherence to diet was evaluated by the modified Alternative Healthy Eating Index. The primary end point was a composite of all-cause mortality, cardiovascular death, cardiac arrest, myocardial infarction, stroke, myocardial revascularization, amputation, or hospitalization for unstable angina. Secondary end points included biochemical and anthropometric data, and blood pressure levels. Results: From March 5, 2013, to Abril 7, 2015, a total of 2534 eligible patients were randomly assigned to either the BALANCE Program group (n = 1,266) or the control group (n = 1,268) and were followed up for a median of 3.5 years. In total, 235 (9.3%) participants had been lost to follow-up. After 3 years of follow-up, mean modified Alternative Healthy Eating Index (scale 0-70) was only slightly higher in the BALANCE group versus the control group (26.2 ± 8.4 vs 24.7 ± 8.6, P <.01), mainly due to a 0.5-serving/d greater intake of fruits and of vegetables in the BALANCE group. Primary end point events occurred in 236 participants (18.8%) in the BALANCE group and in 207 participants (16.4%) in the control group (hazard ratio, 1.15; 95% CI 0.95-1.38; P =.15). Secondary end points did not differ between groups after follow-up. Conclusions: The BALANCE Program only slightly improved adherence to a healthy diet in patients with established CVD and had no significant effect on the incidence of cardiovascular events or death. © 2019 The Author