L'utilisation intensive des produits phytosanitaires, en particulier les insecticides, provoque des effets indésirables sur les organismes vivants et leur environnement. Mon travail de thèse a consisté à évaluer l'effet de deux insecticides chez un insecte modèle la drosophile. Une première étude concernait l'effet d'un néonicotinoïde, l'imidaclopride. Nous avons pu montrer que l'exposition chronique à des doses sublétales de cet insecticide perturbe la fonction de reproduction chez la drosophile. D'autre part, une exposition aiguë à l'imidaclopride a mis en évidence une résistance chez les femelles d'une souche de drosophile dite ''des champs''. Deux mécanismes différents ont été mis en évidence dans la résistance à l'imidaclopride de cette souche. Le premier concerne la sous expression d'une sous-unité (D1) du récepteur nicotinique à l'acétylcholine, cible de l'imidaclopride. Le deuxième concerne l'implication des glutathion S-transférases, enzymes de détoxification, dans le métabolisme de l'imidaclopride. Ces études montrent que les insecticides peuvent avoir en plus des effets sur les insectes ravageurs, des effets néfastes sur des organismes non cibles. La deuxième étude avait pour but de modéliser chez la drosophile, l'impact d'un organochloré, la dieldrine, potentiellement impliquée dans la maladie de Parkinson chez l'homme. L'exposition à cet insecticide conduit à une dégénérescence des neurones dopaminergiques ainsi qu'une perturbation de la structure de régions particulières du cerveau. Nous avons également montré des altérations du métabolisme et l'implication de processus épigénétiques dans la neurodégénérescence induite par la dieldrine. Au cours de ce travail, nous avons pu montrer l'intérêt de nouvelles méthodes comme l'Imagerie par Résonance Magnétique (IRM) ou le High Resolution Magic Angle Spinning (HRMAS) dans ce type d'étude.

Haematophagous parasites and disease vectors such as leeches, ticks, mites, lice, bed bugs, mosquitoes, and myiasis-causing fly larvae are common health problems in Lao Peoples Democratic Republic (Lao PDR). A main aim of my field work in Lao PDR in 2006-2010 was to document traditional knowledge among different ethnic groups about plants that people use to repel or to kill blood-feeding invertebrates. We carried out structured interviews in 66 villages comprising 17 ethnic groups, covering a range of ethnic group, throughout Lao PDR and recorded a total of 92 plant species - in 123 different plant-ectoparasite combinations - that are used as traditional repellents and/or as “pesticides” to kill "pest" invertebrates. Traditional use was confirmed in the scientific literature for 74 of these plant species, and for an additional 13 species based on literature on closely related species. We concluded that repellents and pesticides from many plant species are commonly used in the Lao countryside. We also investigated traditionally used Lao plants for their activity to repel or to kill certain disease vectors and parasites. Target organisms were mosquitoes (Diptera, Culicidae), fly larvae (Diptera, Cyclorrhapha) in fermented fish production, and terrestrial blood-sucking leeches (Hirudinea, Haemadipsidae). The potential mosquito repellent activities of essential oils of Croton roxburghii (Euphorbiaceae), Hyptis suaveolens (Lamiaceae), and Litsea cubeba (Lauraceae) were evaluated in the field near Vientiane. Oils at concentrations of 1.7-6.7 µg/cm2 were significantly repellent to Aedes, Armigeres and Culex attracted to human baits. The activities against fly larvae, infesting fermenting fish, of three plant species, Tadehagi triquetrum (Fabaceae), Uraria crinita (Fabaceae) and Bambusa multiplex (Poaceae) were investigated: When fresh material of the plants was added on top of fermenting fish infested with fly larvae significant proportions of the larvae were repelled or killed. The total protective effect, i.e., repellent and killing effect combined, of T. triquetrum, U. crinita, and B. multiplex was 60-83 %, 77-90 %, and 60-93 %, respectively. Field evaluation of the potential leech repellent activities of water extracts of Sapindus rarak (Sapindaceae), Catunaregam spathulifolia (Rubiaceae) and Vernonia elaeagnifolia, (Asteraceae) impregnated on stockings and worn by persons in two leech-infested biotopes revealed leech repellent activities of 82.6%, 62.6% and 63.0%, respectively. The corresponding repellencies of deltamethrin and diethyl-3-methyl-benzamide (DEET) were 73.1% and 88.4%, respectively. Identification of the active components in certain of the plants with the ultimate aim to develop more optimal, less costly repellents, insecticides, acaricides, and anti-leech compounds as alternatives to synthetic repellents and pesticides against blood-feeding insects, ticks, mites, and leeches is in progress.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 4 uppsatser.

Made available in DSpace on 2015-03-26T13:30:20Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1603340 bytes, checksum: 135e2fd308ff1af60f963623548c94b3 (MD5) Previous issue date: 2006-02-17 / Empresa Brasileira de Pesquisa Agropecuária / The resistance of the insect-pests to fumigants has been frequently reported in stored grains and a present is one of the great obstacles to the control programs involving the use of chemical pesticides. This study was therefore carried out to detect phosphine resistance in populations of Tribolium castaneum, Rhyzopertha dominica and Oryzaephilus surinamensis and to recognize the existence of adaptative disadvantages of these insects in the absence of phosphine, by correlating the instantaneous rate of population growth (ri) with the resistance levels observed in different populations of the species under study. Twelve distinct populations of T. castaneum, ten of R. dominica, and eight of O. surinamensis collected in the states of Goiás, Mato Grosso, Minas Gerais and São Paulo were surveyed. The bioassays for the detection of phosphine resistance were carried out following the standard method recommended by the Food and Agriculture Organization of the United Nations (FAO), which it is based on the exposure of 50 non-sexed adult insects, in four replicates, to the discriminating concentration (DC) of the fumigant for a 20 hourperiod. Later, the concentration-response bioassays were carried out generating the concentration-mortality curves that were used to estimate LC50 and LC95 of the populations pertaining to those three species. The LC50 were used to discriminate the standard population for susceptibility in each species. The measurements of the body mass, CO2 production, and instantaneous rate of population increase (ri) in each population of each species were correlated to the resistance ratio at the LD50. The resistance ratio in T. castaneum ranged from 1,0 to 186,2-fold, whereas in R. dominica it ranged from 2,0 to 71,0-fold, and the lowest one from 1,9 to 32,2-fold for O. surinamensis. The results obtained in the resistance detection bioassays pointed out ten populations of T. castaneum, nine of R. dominica and seven of O. surinamensis that were resistant to phosphine. The relationship between the body mass and CO2 production was positive and significant indicating an increase in CO2 production with the individual body mass. The same effect is observed in the interaction between the instantaneous rate of population increase (ri) and body mass. In addition, the populations with lower CO2 production showed higher resistance ratio (RR) for all species, what is related to the phosphine resistance mechanism. The populations with higher ri showed lower resistance ratio (RR). This result indicates a worse reproductive performance of the resistant populations compared with the susceptible ones. Thus, the management strategies that are based on the interruption of the phosphine fumigation over determined time for the reestablishment of the susceptibility and eventual reintroduction of the fumigant shows a good perspective as a management tactic since the resistant populations under study showed adaptative disadvantage in relation to the susceptible ones in the absence of phosphine. / A resistência a inseticidas fumigantes em insetos-praga de grãos armazenados tem sido freqüentemente registrada e, atualmente, tem se tornado um dos grandes obstáculos aos programas de controle envolvendo o uso de produtos químicos. Com isso, objetivou-se neste estudo detectar populações de Tribolium castaneum, Rhyzopertha dominica e Oryzaephilus surinamensis resistentes à fosfina, além de aferir a existência de desvantagens adaptativas destas, na ausência da fosfina, correlacionando-se produção de CO2, massa corpórea e taxa instantânea de crescimento populacional (ri), com os níveis de resistência observados nas diferentes populações das três espécies em estudo. Foram utilizadas 12 populações distintas de T. castaneum, 10 de R. dominica e oito populações de O. surinamensis, coletadas nos Estados de Goiás, Mato Grosso, Minas Gerais e São Paulo. Os bioensaios para detecção de resistência foram conduzidos conforme método-padrão, recomendado pela Food and Agriculture Organization of the United Nations (FAO), que é baseado na exposição de 50 insetos adultos, em quatro repetições, por um período de 20 horas à concentração discriminante (CD) do gás fumigante. Posteriormente, foram conduzidos bioensaios de concentração-resposta gerando, assim, as curvas de concentração-mortalidade que foram utilizados para estimar as CL50 e CL95 das populações das três espécies. As CL50, por sua vez, foram utilizadas para discriminar a população padrão de suscetibilidade de cada espécie e o nível de resistência das demais populações. A mensuração da massa corpórea, produção de CO2 e taxa instantânea de crescimento (ri) de cada população, das três espécies avaliadas, foram correlacionados à razão de resistência para CL50. A razão de resistência para CL50 em T. castaneum variou de 1,0 a 186,2 vezes, enquanto em R. dominica foi de 2,0 a 71,0 vezes e em O. surinamensis observou-se a menor variação, de 1,9 a 32,2 vezes. Os resultados obtidos nos bioensaios de detecção de resistência indicaram 10 populações de T. castaneum, nove de R. dominica e sete de O. surinamensis resistentes a fosfina. A relação entre massa corpórea e produção de CO2 foi significativa, indicando aumento na produção de CO2 com o incremento da massa corpórea dos indivíduos, nas três espécies avaliadas. O mesmo efeito é observado na interação entre taxa instantânea de crescimento populacional (ri) e a massa corpórea. As populações com menor produção de CO2 apresentaram maior razão de resistência (RR) para CL50, para as três espécies avaliadas, fato que está relacionado ao mecanismo de resistência dos insetos à fosfina. As populações com maiores valores médios de ri apresentaram menor razão de resistência (RR) para CL50, nas três espécies avaliadas. Este resultado indica pior desempenho reprodutivo das populações resistentes, em relação às populações suscetíveis na ausência do fumigante. Portanto, estratégias de manejo da resistência que são baseadas na interrupção da fumigação com fosfina, por determinado tempo visando o restabelecimento da suscetibilidade e eventual reintrodução do fumigante apresentam boa perspectiva de sucesso. Isto porque, as populações resistentes avaliadas neste estudo apresentaram desvantagens adaptativas, em relação às suscetíveis, na ausência da fosfina.

Made available in DSpace on 2015-03-26T13:30:44Z (GMT). No. of bitstreams: 1 texto completo.pdf: 222838 bytes, checksum: f5c4d1de7fe97130246bfd2cf5fd9e84 (MD5) Previous issue date: 2012-07-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The present study was developed in order to evaluate the effects of three plant species extracts on the leaf-cutting ant Atta sexdens rubropiloa colonies. We used leaves of Ageratum conyzoides ( mentrasto ), Coriandrum sativum (coriander) and Mentha piperita (peppermint) species. The activities were conducted at the Federal University of Viçosa campus, in Viçosa-MG. First, we evaluated the effects of these plant extracts on workers physiology, through the immune response and respiratory metabolism. The extracts of coriander and mentrasto had an effect on the ants physiology. The workers increased their immune response when treated with the coriander extract. The mentrasto extract increased the respiratory metabolism of the ants. In another step, we investigated the effect of the extracts on the development of Leucoagaricus gongylophorus, the symbiotic fungus of leaf-cutting ants. It was found that the three extracts adversely affected the fungus growth causing complete inhibition of its development. The best performances were obtained with peppermint and mentrasto extracts that caused high reduction in the biomass of L. gongylophorus even at lower concentrations. Finally, we evaluated the mortality of ant nests after offering baits manufactured with leaves of the three plant species. The results indicated that the baits were unable to cause colony mortality. However, it was found that the treated nests stopped their cutting activity, suggesting baits´ effect on the colonies. Therefore A. conyzoides, C. sativum and M. piperita have deleterious effects on Atta sexdens rubropilosa colonies, and may be promising on the leaf-cutting ants control. / Este estudo foi desenvolvido a fim de se conhecer os efeitos de extratos de três espécies vegetais sobre colônias da formiga-cortadeira Atta sexdens rubropilosa (saúva-limão). Foram usadas folhas das espécies Ageratum conyzoides (mentrasto), Coriandrum sativum (coentro) e Mentha piperita (hortelã). As atividades foram realizadas no campus da Universidade Federal de Viçosa, na cidade de Viçosa-MG. Primeiramente, foram avaliados os efeitos do extrato hexânico dessas plantas na fisiologia das operárias da formiga-cortadeira, através de sua resposta imune e de seu metabolismo respiratório. Os extratos de coentro e mentrasto apresentaram efeito na fisiologia das formigas. As operárias tiveram elevação de sua resposta imune, quando tratadas com o extrato de coentro. O extrato de mentrasto aumentou o metabolismo respiratório das formigas. Em outra etapa, foi investigado o efeito do extrato dessas plantas sobre o desenvolvimento de Leucoagaricus gongylophorus, o fungo simbionte das cortadeiras. Constatou-se que os três extratos afetaram negativamente o crescimento do fungo, causando completa inibição do seu desenvolvimento. Os melhores desempenhos foram obtidos com os extratos de hortelã e de mentrasto, que mesmo nas menores concentrações causaram elevada redução na biomassa de L. gongylophorus. Finalmente, foi avaliada a mortalidade de formigueiros de saúva-limão após oferecimento de iscas confeccionadas a base de folhas das três espécies de plantas. Os resultados indicaram que as iscas não foram capazes de causar mortalidade das colônias. Entretanto, verificou-se que os formigueiros tratados tiveram sua atividade de corte paralisada, indicando efeito das iscas sobre as colônias. Conclui-se, assim, que as espécies A. conyzoides, C. sativum e M. piperita apresentam efeitos deletérios sobre as colônias de A. sexdens rubropilosa, sendo promissoras no controle de formigas-cortadeiras.

Made available in DSpace on 2015-03-26T13:30:55Z (GMT). No. of bitstreams: 1 texto completo.pdf: 425912 bytes, checksum: f916df0f0bb071da87434b28d89e5189 (MD5) Previous issue date: 2007-07-16 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Sitophilus zeamais Motsch. (Coleoptera: Curculionidae) is an important pest of stored maize because of the losses caused. This insect has been studied for responding to selection pressure for insecticide resistance, which impairs its control. In the present study, we carried out a survey of physiological and behavioral resistance to two organophosphate insecticides in 15 populations of S. zeamais collected in Brazil and Paraguay and investigated if differences in population growth, body size and metabolic rate were associated with the resistance. The insects were maintained in the laboratory, and concentration-mortality bioassays were conducted to determine lethal concentrations with 48 hours of exposure. Behavioral resistance was studied by recording the walking behavior on insecticide-treated and untreated surfaces and determining the distance walked, speed, resting time, and proportion of time spent on the treated surface. The instantaneous rate of population growth (ri) was determined, and so was the maize consumption for 90 days, body mass, and production of CO2 as indicative of the metabolic rate of the insects. Results of the concentration-mortality bioassays indicated variations in susceptibility to methyl clorpiriphos (≤ 6,06x) and fenitrothion (≤ 7,71x) relative to the standard susceptible population (Sete Lagoas), but these resistance levels are low and should not cause control failures in the field. The walking behavior on treated surfaces also varied among the populations, but no clear evidence of repellency was detected and no significant correlation was observed between physiological and behavioral resistance. The instantaneous rate of population increase and the respiratory rate were similar among the populations although there were differences in food consumption and body mass of the insects. Importantly, none of these four traits correlated with organophosphate resistance in the populations studied, suggesting absence of detectable fitness costs. We can conclude that the levels of resistance to methyl clorpiriphos and fenitrothion are low, and the physiological resistance in these populations is independent of the behavioral resistance. Furthermore, and even due to the low levels of organophosphate resistance detected, no fitness costs associated with insecticide resistance seems to occur. / Sitophilus zeamais Motsch. (Coleoptera: Curculionidade) é reconhecidamente importante pelos danos causados a grãos de milho armazenados. Essa espécie tem sido bastante estudada por responder à pressão de seleção para resistência a inseticidas, dificultando seu controle. Neste trabalho foi realizado um levantamento da resistência fisiológica e comportamental a dois inseticidas organofosforados em 15 populações de S. zeamais coletadas em vários estados do Brasil e no Paraguai e investigado se características corporais, metabólicas e demográficas estão associadas à resistência. Os insetos foram mantidos em laboratório e testados mediante bioensaios de concentração-mortalidade para determinação de doses letais com 48 horas de exposição. Insetos de cada população foram também submetidos a ensaios de caminhamento em superfície tratada e não-tratada com inseticida para detecção de resistência comportamental, onde foi avaliada a distância caminhada, a velocidade de caminhamento, o tempo em repouso e a proporção de tempo em que os insetos permaneceram sobre a superfície tratada. Foram também determinados a taxa instantânea de crescimento populacional (ri), e o consumo alimentar de milho por 90 dias, além da massa corporal dos indivíduos de cada população estudada. Determinou-se ainda a produção de CO2 como indicativo da taxa metabólica dos insetos. Os resultados dos bioensaios de concentração-mortalidade indicaram variação de suscetibilidade a clorpirifós-metílico (≤ 6,06x) e fenitrotiom (≤ 7,71x) em relação à população padrão de suscetibilidade (Sete Lagoas). Entretanto, este baixo nível de resistência não deve ser alarmante a ponto de levar a falhas de controle no campo e nem parece haver um padrão de distribuição espacial da mesma. As características comportamentais de caminhamento na área tratada variaram entre as populações, embora não pareça haver repelência pelos inseticidas. Não se detectou diferença significativa na taxa instantânea de crescimento populacional e nem na taxa respiratória dos insetos, apesar de haver diferenças de consumo alimentar e massa corporal dos insetos das diferentes populações. É importante salientar que nenhuma dessas quatro características esteve associada com a resistência a inseticidas apresentada pelas populações, indicando que a incipiente resistência aos fosforados das populações estudadas parece não estar associada a custos adaptativos. Pode-se concluir que os níveis de resistência a clorpirifós-metílico e fenitrotiom detectados neste estudo são baixos e a presença de resistência fisiológica nas populações é independente da resistência comportamental. Além disto, e até em função dos baixos níveis de resistência observados, não há indícios de custos adaptativos associados à resistência.

Baculoviruses are arthropod-specific DNA viruses that are highly virulent to most lepidopteran insects. Their host specificity and compatibility with IPM programmes has enabled their usage as safe microbial insecticides (biopesticides). Two baculovirus-based biopesticides, Cryptogran and Cryptex, which have been formulated with Cryptophlebia leucotreta granulovirus (CrleGV) have been registered for the control of false codling moth (FCM), Thaumatotibia (=Cryptophlebia) leucotreta (Meyrick) (Lepidoptera: Tortricidae) in South Africa and have been successfully incorporated into IPM programmes. However, several studies have indicated that insects can develop resistance to baculovirus-based biopesticide as was shown with field populations of codling moth (CM), Cydia pomonella (L.), which developed resistance to the biopesticide Cydia pomonella granulovirus (CpGV-M) in Europe. Other studies have shown that, under laboratory conditions, FCM populations differ in their susceptibility to Cryptogran and Cryptex. In order to investigate difference in susceptibility as well as protect against any future resistance by FCM to Cryptogran and Cryptex, a search for novel CrleGV-SA isolates from diseased insects from different geographic regions in South Africa was performed. Six geographic populations (Addo, Citrusdal, Marble Hall, Nelspruit, Baths and Mixed colonies) of FCM were established and maintained in the laboratory. Studies on the comparative biological performance based on pupal mass, female fecundity, egg hatch, pupal survival, adult eclosion and duration of life cycle of the Addo, Citrusdal, Marble Hall, Nelspruit and Mixed colonies revealed a low biological performance for the Citrusdal colony. This was attributed to the fact that FCM populations found in the Citrusdal area are not indigenous and may have been introduced from a very limited gene pool from another region. When insects from five colonies, excluding the Baths colony, were subjected to stress by overcrowding , a latent baculovirus resident in the Addo, Nelspruit, Citrusdal, Marble Hall and Mixed colonies was brought into an overt lethal state. Transmission electron micrographs revealed the presence of GV occlusion bodies (OBs) in diseased insects. DNA profiles obtained by single restriction endonuclease analysis of viral genomic DNA using BamH 1, Sa/1, Xba1 , Pst1, Xh01 , Kpn1, Hindlll and EcoR1 revealed five CrleGV-SA isolates latent within the insect populations. The new isolates were named CrleGV-SA Ado, CrleGV-SA Cit, CrleGV-SA Mbl, CrleGVSA Nels and CrleGV-SA Mix isolates. The novelty of the five CrleGV-SA isolates was confirmed by the presence of unique submolar bands, indicating that each isolate was genetically different. PCR amplification and sequencing of the granulin and egt genes from the five isolates revealed several single nucleotide polymorph isms (SNPs) which, in some cases, resulted in amino acid substitutions. DNA profiles from RFLPs, as well as phylogenetic analysis based on granulin and egt sequencing showed the presence of two CrleGV-SA genome types for the CrleGV-SA isolate. Cryptex and CrleGV-SA Ado, CrleGV-SA Cit, CrleGV-SA Mbl and CrleGV-SA Mix were placed as members of Group one CrleGV-SA, and Cryptogran and CrleGV-SA Nels isolate were placed into Group two CrleGV-SA. In droplet feeding bioassays, the median survival time (STso) for neonate larvae inoculated with Group one and two CrleGV-SA were determined to range from 80 - 88 hours (3.33 - 3.67 days), for all five colonies. LDso values for Group one and two CrleGV-SA against neonates from the Addo, Citrusdal, Marble Hall, Nelspruit and Mixed colonies varied between some populations and ranged from 0.80 - 3.12 OBs per larva, indicating some level of variation in host susceptibility. This is the first study reporting the existence of genetically distinct CrleGV baculovirus isolates infecting FCM in different geographical areas of South Africa. The results of this study have broad-ranging implications for our understanding of baculovirus-host interactions and for the application of baculovirus basedbiopesticides.

Submitted by Socorro Pontes (socorrop@ufersa.edu.br) on 2017-02-08T15:08:05Z No. of bitstreams: 1 ThaísAK_DISSERT.pdf: 1952872 bytes, checksum: d756cff8a38a02ad11767b390ea5ce27 (MD5) / Made available in DSpace on 2017-02-08T15:08:05Z (GMT). No. of bitstreams: 1 ThaísAK_DISSERT.pdf: 1952872 bytes, checksum: d756cff8a38a02ad11767b390ea5ce27 (MD5) Previous issue date: 2016-02-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Visceral leishmaniasis (VL) is a potentially fatal chronic disease when left untreated. In Brazil, is caused by the protozoan Leishmania infantum is transmitted primarily by sandfly Lutzomyia longipalpis, the dog as the main reservoir. The control of this disease has been in a challenge to public health, and as a proposal for a measure of control of canine VL using dog collars impregnated with deltamethrin to 4% in dogs. Thus, the research aims to assess the effectiveness of these collars on the prevalence of canine VL and infection rate of sandfly to L. infantum in endemic areas for VL. The survey was conducted in two areas equidistant from the city of Mossoró/RN, with similar environmental characteristics. In both of these areas were carried out two surveys every six months and to serologic canines are search for a year, and in a were performed only the procedures mentioned above, being named Control Area (AC) and the other, in addition to the steps mentioned earlier were also carried out two collaring dogs with collars impregnated with deltamethrin the 4% that occurred every six months This area was named “Encoleiramento” Area (AE). For diagnosis of canine VL was made DPP and ELISA. The analysis of the prevalence of canine VL was carried out through the Chi-square test and the incidence rate of the disease through the Odds ratio. For the collection of sandflies were selected three houses in each of the areas, the insects were collected monthly using CDC light traps and separated by species, sex, stage of investigation and research. The morphological identification of sandflies and the females were subjected to real-time PCR for the detection of DNA of L. infantum. With regard to prevalence and incidence rates of VL, evaluating the areas in isolation, one could observe that the use of dog collars was able to reduce the prevalence of the disease in AE and 53 to 59% reduction in the risk of illness. As the sandfly, collected the species L. longipalpis, L. evandroi, L. cortelezzii and L. migonei, with 81,8% % L. longipalpis. Positive pools were obtained from L. longipalpis of AE only during the first investigation while in AC could observe the presence of DNA of the parasite in vector in both investigations. Based on the results, the use of impregnated with deltamethrin collars to 4% has the potential to reduce the prevalence of canine VL as well as allows a reduction in at least 53% the risk of illness. It is also possible to suggest that the continued use of these dog collars can have the potential to reduce the rate of infected sandflies. Thus, impregnated with deltamethrin collars to 4% can be indicated as a control measure for the disease, together with other measures currently recommended / A leishmaniose visceral (LV) é uma doença crônica potencialmente fatal quando não tratada. No Brasil, é causada pelo protozoário Leishmania infantum é transmitida principalmente pelo flebotomíneo Lutzomyia longipalpis, tendo o cão como principal reservatório urbano. O controle desta afecção tem consistido em um desafio para a Saúde Pública, e como proposta de medida de controle da LV canina tem-se a utilização de coleiras impregnadas com deltametrina a 4% em cães. Assim, a pesquisa tem como objetivo avaliar a efetividade dessas coleiras sobre a prevalência da LV canina e taxa de infecção de flebotomíneos para L. infantum em áreas endêmicas para LV. A pesquisa foi realizada em duas áreas equidistantes do município de Mossoró/RN com características ambientais semelhantes. Em ambas as áreas foram realizados dois inquéritos sorológicos caninos semestrais e a pesquisa de flebotomíneos. Na Área Controle (AC) foram realizados os procedimentos anteriormente citados e na Área Encoleiramento (AE) foram também realizados dois encoleiramentos caninos com coleiras impregnadas com deltametrina a 4% que ocorreram a cada seis meses. Para diagnóstico da LV canina foram realizados o teste rápido DPP e ELISA. A análise da prevalência da LV canina foi realizada através do teste de Qui-quadrado e da taxa de incidência através do Odds ratio. A pesquisa de flebotomíneos teve duração de um ano em três residências de cada uma das áreas. Os insetos foram coletados mensalmente utilizando armadilhas luminosas tipo CDC e separados por espécie, sexo, primeiro ou segundo inquérito e área da pesquisa. Foi realizada a identificação morfológica dos flebotomíneos e as fêmeas foram submetidas à técnica de PCR em tempo real para a detecção de DNA de L. infantum. Com relação às taxas de prevalência e incidência da LV canina, avaliando-se as áreas isoladamente, pôde-se observar que o uso das coleiras foi capaz de reduzir a prevalência da doença na AE e reduzir em 53 a 59% o risco de adoecimento. Quanto aos flebotomíneos, foram coletadas as espécies L. longipalpis, Lutzomyia evandroi, Lutzomyia cortelezzii e Lutzomyia migonei, sendo que 81,8% destes insetos eram L. longipalpis. Foram obtidos pools positivos de L. longipalpis da AE somente durante o primeiro inquérito ao passo que na AC pôde-se observar a presença do DNA do parasita no vetor em ambos os inquéritos. Com base nos resultados, pode-se afirmar que a utilização de coleiras impregnadas com deltametrina a 4% reduziu a prevalência da LV canina, e permite reduzir em pelo menos 53% o risco de adoecimento. Também é possível sugerir que o uso contínuo destas coleiras pode ter o potencial de reduzir a taxa de flebotomíneos infectados. Dessa forma, coleiras impregnadas com deltametrina a 4% podem ser indicadas como medida de controle para a LV canina, aliada as demais medidas atualmente preconizadas / 2017-02-08

Submitted by Socorro Pontes (socorrop@ufersa.edu.br) on 2017-04-11T18:53:42Z No. of bitstreams: 1 IdalecioPS_TESE.pdf: 5907205 bytes, checksum: 814ed97201f439fa05e27b9c404b4908 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-04-13T15:20:53Z (GMT) No. of bitstreams: 1 IdalecioPS_TESE.pdf: 5907205 bytes, checksum: 814ed97201f439fa05e27b9c404b4908 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-04-26T12:13:04Z (GMT) No. of bitstreams: 1 IdalecioPS_TESE.pdf: 5907205 bytes, checksum: 814ed97201f439fa05e27b9c404b4908 (MD5) / Made available in DSpace on 2017-04-26T12:13:13Z (GMT). No. of bitstreams: 1 IdalecioPS_TESE.pdf: 5907205 bytes, checksum: 814ed97201f439fa05e27b9c404b4908 (MD5) Previous issue date: 2015-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Pollinators are among the essential components for the functioning of ecosystems in general, because it is essential for the reproduction and maintenance of the diversity of plant species and provide food for humans and animals, also influencing the qualitative aspect of the production. Currently, the population density of many pollinators are being reduced to levels that can impair pollination services. The decline of honeybee Africanized (Apis mellifera L.) populations impacts global agricultural production and has a clear impact on both food production and the economy. One of the probable causes for this decline is the indiscriminate use of pesticides. Thus, there was comparative levels of exposure to pesticides among bees (Apis mellifera L.) that are used to pollinate melon crops, bees (Apis mellifera L.) kept in the bush, and Jandaira bees (Melipona subnitida ) kept in the bush. To do this, honey samples were collected from 23 colonies of Apis mellifera used to pollinate melon palntações, 20 colonies of Apis mellifera foraging forest and 10 colonies of Melipona subnitida foraging in the forest. The level of exposure to pesticides was determined by measuring the residual levels of 152 compounds in honey using a multiresidue analysis technique in UFLC-MS system. Honey samples from the present study contained 19 different pesticides, 13 of which were present in honey from bees pollinating melon crops. The levels of some compounds were sufficiently high to promote adverse effects in the bees. Thus, crop pollination offers a great toxicological risk to bees that may contribute to colony collapse / Os polinizadores estão entre os componentes essenciais para o funcionamento dos ecossistemas em geral, pois é essencial para a reprodução e manutenção da diversidade de espécies de plantas e provê alimentos para humanos e animais, influenciando, também, o aspecto quantitativo e qualitativo da produção. Atualmente, a densidade populacional de muitos polinizadores está sendo reduzida a níveis que podem comprometer os serviços de polinização. O declínio das populações de abelhas (Apis mellifera L.) tem impactado na produção agrícola mundial e tem um impacto claro sobre a produção de alimentos e da economia. Uma das causas prováveis para este declínio é o uso indiscriminado de agrotóxicos. Desta forma, fez-se estudo comparativo dos níveis de exposição aos pesticidas entre as abelhas Apis mellifera L. (africanizadas) que são usadas para polinizar plantações de melão, as abelhas Apis mellifera L.(africanizadas) mantidas na caatinga, e as abelhas jandaíra (Melipona subnitida) mantidas na caatinga. Para isso, amostras de mel foram coletadas de 23 colônias de abelhas africanizadas Apis mellifera utilizadas para polinizar plantações de melão, 20 colônias de abelhas africanizadas Apis mellifera que forrageiam de na caatinga e 10 colônias de Melípona subnitida que forrageiam na caatinga. O nível de exposição aos pesticidas foi determinado medindo os níveis residuais de 152 compostos no mel, utilizando uma técnica de análise de multiresíduos no sistema UFLC-MS. As amostras de mel estudadas apresentaram 19 pesticidas diferentes, 13 dos quais estavam presentes no mel de abelhas polinizadoras das plantações de melão. Os níveis de alguns compostos foram suficientemente elevados para promover efeitos adversos em abelhas. Assim, a polinização das culturas oferece um grande risco de toxicidade para as abelhas que pode contribuir para o colapso da colônia / 2017-04-11

[Summary]: The larvae of Anomala opacicollis (Pér), of Melolonthid and of other Rutelid species, attack tobacco in Southern Rhodesia, and are more commonly called "whitegrubs". Whitegrubs are widespread in the sandveld areas where tobacco is grown and, at the Trelawney Station of the Tobacco Research Board of Southern Rhodesia, where this work was done, A. opacicollis was the predominant species. An account o£ the one year life cycle is given. The adults eat the leaves of various indigenous trees and an account of an experiment on the food preferences of A. opacicollis adults is given, and the main food sources in the Trelawney area are listed. An experiment is described which shows that the beetles prefer to lay their eggs in the veld or in manured broken land rather than in normal ploughed lands. The larvae are erratically distributed in lands and experiments on larval movement suggest that this is mainly due to concentration of the larvae at discrete concentrations of organic matter in the soil. The temperature and moisture condition of the top 3" of soil are found to be those which attact the larvae. It is suggested that tho larvae prefer and move to soil which contains the lowest amount of moisture which keeps the soil air spaces saturated. lt appears that the preferred temperature decreases with increasing soil moisture content and it is suggested that this is due to the respiratory requirements of the larvae. Soil pH, compaction and fertiliser content and the presence of plants do not appear to influence larval movements. A theory is developed concerning the mechanism of movements in the soil and it is suggested that, in the absence of a continuous gradient, the speed but not the direction of movement is influenced by conditions to which the larvae are sensitive. Evidence in support of thie theory is given. Studies on the survival of larvae at different soil moisture contents and temperatures show that conditions in the top 3" of soil are not likely to be lethal in spite of the high temperatures and low moisture contents found there. The relation of whitegrub behaviour to agricultural problems is discussed. Other workers published evidence indicating that early ploughed lands were attractive to whitegrubs; this is shown not to be the case and the previous evidence is re-interpreted. Such lands tend to contain concentrations of whitegrubs round the borders. The reason for this is discussed and it is suggested that lands should be ploughed early to confine whitegrub infestations in this manner. Soils low in fertility through repeated cultivation are commonly believed to contain more whitegrubs than virgin soil. However, behaviour studies suggest that it is the activity and not the size of the population which is affected by soil fertility. The time at which tobacco is planted is known to determine the extent of subsequent whitegrub damage. The reason for this is to be found in the life cycle of whitegrubs and the results of an experiment on time of planting in relation to whitegrub damage are given. Some insecticides are shown to be more repellant than others to A. opacicollis larvae and the influence of this fact on the assessment of soil insecticide effectiveness in the field is discussed. Reference is made to a method developed by the writer for the determination of insecticide effectiveness under the conditions of erratic whitegrub distribution which normally occur.