Bacillus sphaericus 2362 is a mosquito pathogenic bacterium. Its greatest industrial potential may be in developing countries where mosquitos are often vectors for diseases. This strain is typical of the species in that it is unable to grow using carbohydrates as a sole source of carbon. The goal of this research was to determine the metabolic deficiency(s) responsible for the inability of this organism to grow on carbohydrates. Compounds that supported light growth of this organism on an agar-solidified, defined medium included acetate, glycerol, and gluconate. Growth in a defined liquid medium with acetate as the source of carbon was much slower than growth in a complex, protein-based broth. B. sphaericus grew poorly in a defined, liquid medium with glycerol or gluconate as the carbon source. Activity of enzymes responsible for the initiation of metabolism of some substrates was not detected in cell extracts. These enzymes were: glucokinase, hexokinase, beta-galactosidase, and amylase. Growth of this bacterium on glycerol as a sole source of carbon implies the presence of the enzymes from the lower half of the Embden-Meyerhof-Parnas (EMP) pathway. Two enzymes of the upper half of the EMF pathway, phosphofructokinase and fructose diphosphate aldolase, were undetected in cell extracts. In addition, glucose dehydrogenase activity was not detected. The inability to form glucose-6-phosphate from glucose prevents the catabolism of this and related substrates via the Entner-Doudoroff (ED), hexose monophosphate (HMP), and EMF pathways. Oxygen uptake studies indicated that B. sphaericus oxidized gluconate slightly but only when the cells were grown in a complex, protein-based medium supplemented with gluconate. Although gluconokinase activity was detected in cell extracts, no activity was detected for the key enzymes of the ED (phosphogluconate dehydratase/KDPG aldolase), or HMP (6-phosphogluconate dehydrogenase) pathway. It is unclear how B. sphaericus grows on a defined medium with gluconate as the sole source of carbon. In addition to enzymatic deficiencies, whole cells were unable to accumulate [¹⁴C]glucose or [¹⁴C]sucrose. / Master of Science

Depression and other mood disorders, as well as cognitive and motor dysfunction have been linked with changes in monoamine levels in the brain. Environmental acetylcholinesterase (AChE) inhibitors, such as organophosphate insecticides (OPs), have also been shown to induce these problems. This study investigated whether insecticide-induced AChE inhibition, induced by chlorpyrifos (CPS), may contribute to the types of forebrain monoaminergic alterations associated with psychiatric, cognitive and motor dysfunction. Increased synaptic ACh, resulting from CPS-induced AChE inhibition, may alter the synthesis or release of monoamines through prolonged action of ACh on monoaminergic neurons that contain ACh receptors. Adult, male Sprague-Dawley rats were subjected to a single subcutaneous dose of CPS or corn oil vehicle. Brains were rapidly removed and the frontal cortex, hippocampus and striatum were bilaterally dissected on ice. These three regions from one side were assayed for AChE activity, while those from the opposite side were processed for high performance liquid chromatography with electrochemical detection (HPLC-ED) analysis of monoamine neurotransmitters and their metabolites. In the initial, exploratory experiment, inhibition of AChE activity was 66.8% in the frontal cortex, 43.8% in the hippocampus and 46.9% in the striatum, 7 days after a 60mg/kg dose of CPS. No significant differences in concentration of monoamine neurochemicals were observed between vehicle control and CPS-treated groups in either the hippocampus or striatum. However, in the frontal cortex of the CPS-treated rats there was a significant increase in median dihydroxyphenylacetic acid (DOPAC) concentration (P=0.019) and a very strong statistical trend toward increased dopamine (DA) concentration (P=0.0506). The second experiment examined the time course of AChE inhibition produced by a higher dose (200mg/kg) of CPS and how monoamine levels changed in conjunction with this pattern of AChE inhibition. Percent inhibition of AChE activity in CPS-treated animals, at 4, 14 and 21 days post-exposure was 77.0%, 86.6% and 81.9% in the frontal cortex, 86.1%, 85.9% and 83.2% in the hippocampus and 90.1%, 89.8% and 85.5% in the striatum. No significant differences in monoamine neurochemicals were observed between vehicle control and CPS-treated groups in either the hippocampus or striatum. A statistical trend toward a decrease in serotonin (5-HT) was seen in the frontal cortex at 14 days (P=0.0753) following CPS exposure. A very consistent, yet non-significant pattern of an increase in monoamines at 4 days post-CPS was observed in all instances, except for 5-hydroxyindoleacetic acid (5-HIAA) in the striatum. Therefore, the final experiment employed a more powerful design to focus on monoamine levels during, or shortly after, the change in AChE activity that rapidly follows exposure to 200mg/kg CPS. This experiment also employed a behavioral analysis on the day of sacrifice to assess the presence or absence of clinical signs of toxicity associated with this dose. Of the 30 CPS-treated rats, only 1 animal displayed a single behavioral sign of cholinergic poisoning. Percent inhibition of AChE activity at 2 and 4 days after treatment was 81.4% and 79.4% in the frontal cortex, 53.4% and 83.5% in the hippocampus, and 80.5% and 87.8% in the striatum. No significant changes in monoamine neurochemicals were observed between vehicle control and CPS-treated groups in either the frontal cortex or hippocampus. However, a significant increase in DOPAC (P=0.0285) in the striatum, 2 days after CPS treatment, was observed. In addition, a strong statistical trend toward decreased striatal 5-HT (P=0.0645) was reported 4 days after CPS treatment. The only significant correlation between AChE activity and monoamine concentration was observed for 5-HIAA in the striatum of CPS-treated, 2 day survivors (P=0.0445). However, it was of low magnitude (r=0.525, r2=0.276). CPS has a limited capacity to produce changes in monoamine neurotransmitters and/or their metabolites in the frontal cortex and striatum of the mammalian brain. These changes are primarily seen in the dopaminergic system. Alterations of monoamines do not appear to be strongly associated with incident levels of AChE inhibition. The biological implication of the limited OP induced changes in central monoamines remains significant, as changes in monoamines in the CNS nervous system have been linked to psychiatric, cognitive and motor dysfunction. / Master of Science

Field experiments (2007-2009) and laboratory bioassays (2009) tested the efficacy of insecticides with short pre-harvest intervals, caneberry cultivar susceptibility, and geranium toxicity for reducing Japanese beetle (JB) activity on primocane-bearing caneberries. Deltamethrin, chlorantraniliprole, bifenthrin, lime-alum, and thyme oil reduced JB activity in the field. Deltamethrin, chlorantraniliprole, acetamiprid, an azadirachtin and pyrethrin mixture, an azadirachtin and neem oil extract mixture, and an extract of Chenopodium ambrosioides reduced JB activity during the bioassays. "Prelude" had significantly more JB than "Anne", "Caroline", "Heritage", "Dinkum", or "Himbo Top" and "Prime-Jan" had significantly more JB than "Prime-Jim". Compared to certain cultivars, "Heritage", "Caroline", "Himbo Top", and "Prime-Jan" had higher percentages of injured fruit and "Autumn Bliss", "Heritage", and "Caroline" produced greater marketable and overall yields. "Prime-Jan" produced more overall yield than "Prime-Jim"; marketable yields from both blackberry cultivars were similar. Defoliation was significantly less for "Dinkum", "Caroline", "Heritage", and "Anne" than for "Prelude" in 2008 and significantly less for "Caroline" and "Anne" than "Prelude" or "Fall Gold" in 2009. In field tests, previous consumption of geraniums lessened raspberry defoliation by JB. Bioassays indicated that JB activity was only reduced if JB were continually exposed to geranium. Therefore, the efficacy of geranium as a trap crop for JB may be limited. The stink bug species within the caneberries were identified (2008-2009) and Euschistus servus (Say) made up 48.1 % of the overall species composition. Stink bug injury to ripening raspberries was identified as small holes between drupelets; stink bug excretions also ruined fruit. / Master of Science in Life Sciences

Selected insecticides were evaluated to determine effects on the potato leafhopper and its predators. Three types of tests were conducted. First, the common predators of the potato leafhopper in alfalfa were examined to determine their response to the stages of the leafhopper. Second, under field conditions, insecticides were tested to detect effects on the populations of the insects. Finally, LC₅₀ toxicities of selected insecticides were investigated under laboratory conditions. In the predation tests, two studies were conducted, namely, predation on egg stage and predation on nymphal and adult stages of the potato leafhopper. An indirect method of determining egg predation was employed because potato leafhopper eggs are not visible, being concealed in the xylem and phloem tissues. Using two sets of treatments (with and without predators), the potato leafhopper females were allowed to oviposit in predation cages and the suspected predators introduced thereafter. Hatching nymphs were counted and used as indications of the number of eggs laid. Nabis americoferus and Orius insidiosis were found to be predaceous on eggs of the potato leafhopper. In the predation tests, using nymphal and adult stages of the potato leafhopper, the following adult and larval stages of insects were confirmed as predators: Hippodamia convergens, Coccinella novemnotata, and Chrysopa carnea. Two field tests, one in summer of 1977 and one in summer of 1978, were conducted to determine the influence of insecticides on populations of potato leafhoppers and its predators in alfalfa. Samples were taken using a 38 cm sweep net employing a 180° motion at 2 days, 1 week, and 2 weeks after treatment. In both tests, significant control was provided by the chemicals against potato leafhoppers 48 hours following application. A gradual population recovery occurred one week and two weeks after treatment. Most of the entomophagous insects sampled were adversely affected by insecticides. No statistical differences in yield and percent dry matter were obtained with various insecticidal treatments. The acute toxicities of selected insecticides on potato leafhopper, tarnished plant bug, and damsel bug were investigated. The bioassay method used was the immersion technique and toxicity was expressed in LC₅₀. The relative toxicities of Nabis americoferus to 50° Empoasca fabae and Lygus lineolaris were obtained by deriving the selectivity ratios. Selectivity ratios are calculated by dividing the LC₅₀ of the non-target organism divided by the LC₅₀ of the pest. The ratios indicated that most of the insecticides tested were highly selective. Among the organophosphates, azinphosmethyl was the most selective, while among the carbamates, carbaryl was the most selective. / Master of Science

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. / Pesticides have been used extensively and induce harmful effects on organisms and their environment. The aim of my PhD work was to investigate the effects of two insecticides by using Drosophila as a model. The first study concerns the effect of a neonicotinoid, imidacloprid. The results obtained have shown that a chronic exposure at sublethal doses of this insecticide affects reproduction in flies. Moreover, acute exposure at high doses has pointed out a resistance phenomenon in females of a field strain. We have shown that two mechanisms are implicated: (i) low expression of a subunit of a nicotinic acetylcholine receptor that is the target of imidaclopride and (ii) role of glutathione S-transférases, detoxication enzymes, in imidaclopride metabolism. These results highlight impact of insecticides, in particular imidaclopride, on non target organisms. The aim of the second study was to characterize in Drosophila, effects of an organochlorine, dieldrin, potentially implicated in the etiology of Parkinson’s disease in humans. Dieldrin exposure at low doses promotes neurodegeneration of dopaminergic neurons and alters structures of particular regions of the brain. Disruption of metabolism is also induced after exposition to dieldrin. In addition, we have shown that epigenetic processes are implicated in neurodegenration induced by dieldrin. This work show advantages of new techniques such as Magnetic Resonance Imaging (MRI) and High Reslution Magic Angle Spinning in this kind of study.

Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: In Uganda, cattle are an important reservoir of Trypanosoma brucei rhodesiense, a parasite that causes human African trypanosomiasis or sleeping sickness. We developed mathematical models to examine the transmission of T. b. rhodesiense by tsetse vector species, Glossina fuscipes fuscipes in a host population that consists of humans, domestic and wild mammals, and reptiles. The models were developed and analysed based on the situation in Tororo district in Southeastern Uganda, where sleeping sickness is endemic and which has a cattle and human population of 40, 000 and 500, 000, respectively. Assuming populations of cattle and humans only, the impact of mass chemoprophylaxis and vector control through insecticide-treated cattle (ITC) is evaluated. Keeping 12% or 82% of the cattle population on insecticides that have an insecticidal killing effect of 100% at all times or trypanocides that have 100% efficacy, respectively, can lead to the control of T. b. rhodesiense in both humans and cattle. Optimal control of T. b. rhodesiense is shown to be achieved through ITC alone or a combination of chemoprophylaxis and ITC, the former being the cheapest control strategy. Allowing for the waning effect of insecticides and including wildhosts, T. b. rhodesiense control can be achieved by keeping 21% or 27% of the cattle population on insecticides through whole-body or restricted application, respectively. Restricting the treatment of insecticides to adult cattle only would require 24% or 33% of the adult cattle population to be kept on insecticides through whole-body or restricted application, respectively, to control T. b. rhodesiense. A cost-effectiveness and benefit-cost analysis of using ITC to control T. b. rhodesiense show that restricted application of insecticides is a cheaper and more beneficial strategy compared to whole-body treatment. The results of the study show that the restricted application of insecticides on cattle provides a cheap, safe and farmer-based strategy for controlling tsetse and trypanosomiasis. / AFRIKAANSE OPSOMMING: In Uganda is beeste ’n belangrike reservoir van Trypanosoma brucei rhodesiense, ’n parasiet wat tripanosomiase of slaapsiekte in mense veroorsaak. Ons het wiskundige modelle ontwikkel wat die oordrag van T. b. Rhodesiense deur tesetse vektor spesies, Glossina fuscipes fuscipes in ’n draer populasie wat bestaan uit mense, mak en wilde diere en reptiele, ondersoek. Die modelle was ontwikkel en geanaliseer gebaseer op die oordrag situasie in die Tororo distrik in Suidoostelike Uganda, ’n gebied waar slaapsiekte endemies is en wat ’n populasie van 40, 000 beeste en 500, 000 mense het. Die impak van massa chemoprofilakse en vektor beheer deur insekdoder-behandelde beeste is gevalueer onder die aanname van bees en mens populasies alleenlik. Beheer oor T. b. Rhodesiense in beide mense en beeste kan verkry word deur of 12% van die bees populasie te behandel met ’n insekdoder wat 100% effektief is ten alle tye of 82% van die bees populasie te behandel met tripanosiedes wat 100% effektief is. Daar is aangetoon dat optimale beheer van T. b. Rhodesiense bereik kan word deur die gebruik van insekdoders alleenlik of ’n kombinasie van insekdoders en chemoprofilakse, hoewel eersgenoemde die goedkoopste strategie is. Wanneer die kwynende effek van insekdoders asook wilde diere as draers in ag geneem word, kan T. b. Rhodesiense beheer verkry word deur 21% van beeste se hele liggaam met insekdoders te behandel of 27% gedeeltelik te behandel. As slegs volwasse beeste met insekdoders behandel word, moet 24% se hele liggaam of 33% gedeeltelik behandel word vir beheer van T. b. Rhodesiense. ’n Koste-effektiwiteit en voordeel-koste analise van insekdoders as beheermaatstaf vir T. b. Rhodesiense toon aan dat gedeeltelike behandeling van die bees se liggaam die goedkoper en meer voordelige strategie is in vergelyking met behandeling van die hele liggaam. Die resultate van die studie wys dat gedeeltelike behandeling van beeste met insekdoders ’n goedkoop, veilige en landbouer-gebaseerde strategie is om tsetse en tripanosomiase te beheer.

Une distribution nationale de moustiquaires imprégnées d'insecticide à longue durée d'action à destination des populations vulnérables du Niger a été effectuée fin 2005. Déjà montrée lors d'études pilotes à l'échelle du village, l'efficacité de cet outil dans le contrôle du paludisme restait à évaluer à l'occasion de vastes programmes opérationnels qui se multiplient en Afrique. Peu d'études des populations de vecteurs ont été publiées dans ce cadre. Nous avons mis en place un suivi entomologique au niveau de sites sentinelles répartis dans la zone Sahélienne du Niger, ayant couvert trois saisons de transmission, dont une avant intervention considérée comme période contrôle. Les paramètres entomologiques de la transmission ont été déterminés pour An. gambiae s.l., et la distribution spatiale des deux principaux vecteurs, An. gambiae et An. arabiensis, a été précisée. Le suivi temporel a mis en évidence une baisse globale du niveau de transmission de P. falciparum, probablement entrainée par la forte hausse d'utilisation de moustiquaires imprégnées. Cependant la hausse de la résistance des populations aux pyréthrinoïdes semble avoir été rapidement amorcée faisant craindre à moyen terme une perte d'efficacité de cet outil central des stratégies de lutte contre le paludisme. L'étude de la structure génétique des populations d'An. gambiae et d'An. arabiensis à l'aide de marqueurs microsatellites a montré une homogénéité génétique dans l'espace, entre les villages, même séparés par plusieurs centaines de kilomètres, ainsi que dans le temps, entre la saison de transmission 2005 contrôle et la saison 2006 après distribution. Ces résultats ont suggéré qu'au cours de la première année d'intervention, la couverture en moustiquaires imprégnées atteinte n'a pas eu d'effet de masse suffisant pour entrainer une baisse de la diversité génétique ou une modification des fréquences alléliques des populations. La faible différenciation spatiale observée pourrait être expliquée par des échanges de gènes importants à l'intérieur de la zone d'étude, hypothèse appuyée par l'expansion rapide de la mutation kdr dans l'ensemble des sites où An. gambiae est présent. L'évaluation rigoureuse de tels programmes de contrôle permettra d'améliorer les outils de contrôle et par exemple de préserver l'efficacité des pyréthrinoïdes, seule classe d'insecticides actuellement disponible pour l'imprégnation des moustiquaires.

No description available.

Programas brasileiros de controle populacional do mosquito Aedes aegypti são caracterizados por incluírem ações integradas entre população e poder público, compreendendo suplementarmente a aplicação de inseticidas nos potenciais criadouros do mosquito. Um dos compostos utilizados para o controle populacional de mosquitos é o Pyriproxyfen, um regulador de crescimento de insetos que age durante os estágios imaturos impedindo a emergência das larvas para a fase adulta. Muitas pesquisas, em condições laboratoriais controladas, encontraram resultados eficientes na aplicação desse larvicida, inferindo a confirmação de eficácia para uso nos programas de controle. Contudo, esses trabalhos disponíveis desconsideram a interferência por fatores ambientais (e.g. temperatura, luminosidade, pH) o que, como consequência, pode apresentar diferenças nos resultados em ambiente natural. Dentre esses fatores, é importante o destaque a temperatura, que apresenta o potencial de produzir diferenças na eficiência do composto, uma vez que há evidências de interferência tanto na velocidade e no sucesso de desenvolvimento das larvas quanto da composição química do larvicida. Dessa forma, o presente trabalho avaliou o efeito da variação da temperatura na eficiência do larvicida Pyriproxyfen para controle populacional de larvas de Aedes aegypti. Para isso, foram realizados experimentos avaliando o efeito combinado de três diferentes temperaturas (20°C, 25°C, 30°C) e cinco diferentes concentrações de Pyriproxyfen (0,0001; 0,001; 0,01; 0,1 e 1 mg.L-1), sendo as dosagens escolhidas em função da recomendação da Organização Mundial da Saúde (0,01 mg/L). Os testes foram realizados em incubadora BOD, com temperatura controlada desde a eclosão para evitar estresse térmico nas larvas. Também foi analisado o efeito sub letal do composto, nas respostas em longevidade dos mosquitos e do tamanho alar como indicador do tamanho das fêmeas provenientes dos tratamentos a 20°C e a 30°C. Quando aumentou-se a temperatura em 5°C (de 25°C para 30°C), houve redução em 30% da eficiência do larvicida na menor dosagem ,redução de 10% da eficácia na concentração de 0,001 mg/L e redução em 20% na concentração de 0,01 mg/L. Para todas as concentrações testadas, os mosquitos sobreviventes tiveram sua longevidade reduzida significativamente se comparados aos mosquitos desenvolvidos em um ambiente sem o composto. Ainda, as fêmeas emergentes do ambiente a 30°C foram significativamente maiores que as fêmeas que se desenvolveram a 20°C. No que se refere ao tamanho de fêmeas, entre a mesma temperatura não houve diferença significativa com relação ao tamanho das asas. Estes resultados indicam que, apesar da alta eficiência do Pyriproxyfen, deve-se considerar com cautela a influência que os fatores ambientais têm sobre o efeito de compostos inseticidas no controle de vetores, uma vez que estes são capazes de interferir no cenário epidemiológico. Ademais, considerar dosagens diferentes de acordo com os fatores ambientais em campo pode trazer benefícios no uso mais racional de compostos inseticidas bem como serem mais eficientes no controle efetivo do vetor alvo. / Surveillance brazilian programs for populational control of the Aedes aegypti mosquito are characterized for applying integrated actions between the government and the municipalities population, comprising as a supplementary measure the application of pesticides. One of these compounds is Pyriproxyfen, a insect growth regulator that acts during the imature stages of the organismo, therefore preventing its emmergence to the adult stage. Many researches, at laboratory conditions, found efficient outcomes by testing this larvicide, inferring its confirmation of efficacy of application during the surveillance programs. However, these studies disconsider the possibility of interference by evironmental factors, such as temperature, luminosity and pH variations. Among these factors, the environmental temperature is highlighted, considering the existing evidence of interference in the larval development and at the chemical composition of the larvicide. Thus, this study aims to assess the temperature effect over the efficiency outcomes of the Pyriproxyfen as a larvicide for Aedes aegypti control. Were executed experiments analyzing the combined effect of three different temperatures (20°C, 25°C, 30°C) and five concentrations of Pyriproxyfen (0,0001 mg/L, 0,001 mg/L, 0,01 mg/L, 0,1 mg/L and 1 mg/L). These tests were performed in a BOD incubator, with controlled and constant temperature, since the eclosion of the I instar larvae until the end of the test. Dead larvae were removed and registered daily. Were analyzed the sub lethal outcomes, by the longevity of the survivors and were calculated the wing size of the females from 20°C and 30°C as na indicator of body size of these female mosquitoes. When increased 5ºC in the temperature, from 25°C to 30°C, were observed an decrease in the efficiency of the larvicide by 30% at the lowest concentration, by 10% at a tem times higher concentration (0,001 mg/L) and a decrease by 20% at the concentration of 0,01 mg/L. For all concentrations assessed, the survivors lived less time than the mosquitoes which developed at na ambient without the Pyriproxyfen contamination. Yet, the females from the warmest environment, at 30ºC, were bigger than the females that developed in a cooler environment (20°C). The results indicate that, despite of the high efficiency of this larvicide, we must consider with caution the influence by environmental factors in field conditions, since that they present the possibility of interfering directly or indirectly at the epidemiologic scenario. Furthermore, considering different dosages according to the environmental factors in the field can bring benefits in the more rational use of insecticidal compounds as well as being more efficient in the effective control of the target vector.

A lagarta-enroladeira Bonagota salubricola (Meyrick, 1937) e a mariposa oriental Grapholita molesta (Busck, 1916) (Lepidoptera: Tortricidae) são duas das mais importantes pragas de frutíferas de clima temperado no Brasil. O manejo destes insetos-praga tem sido realizado quase que exclusivamente com inseticidas. Para a implementação de estratégias de manejo pró-ativo de resistência, é importante conhecer o estado atual de suscetibilidade destas espécies a inseticidas para detectar a resistência antes que se observem falhas no controle. Nas condições brasileiras, em regiões onde estes pomares são plantados próximos em algumas regiões, acredita-se que G. molesta disperse para a cultura da maçã após a colheita do pêssego, dependendo da proximidade espacial e temporal dos pomares. Portanto, este trabalho teve como objetivos, caracterizar a suscetibilidade de B. salubricola e G. molesta aos principais inseticidas recomendados para o controle e avaliar a estrutura genética de populações de G. molesta provenientes das culturas da macieira e pessegueiro no Brasil. A caracterização da suscetibilidade foi realizada com bioensaio de ingestão com tratamento superficial da dieta com inseticidas, utilizando-se lagartas neonatas provenientes de populações de B. salubricola coletadas em macieira no Estado do Rio Grande do Sul (safra 2011/12) e de G. molesta provenientes de pomares do Rio Grande do Sul (2010/11 e 2011/12), Santa Catarina (2010/11) e São Paulo (2010/11 e 2011/12). Não foram observadas diferenças na suscetibilidade de populações de campo de B. salubricola em relação à população suscetível de referência aos inseticidas chlorantraniliprole, phosmet, spinetoram, spinosad e tebufenozide, assim como não foram detectadas diferenças na suscetibilidade de populações de G. molesta a chlorantraniliprole, metaflumizone, novaluron, pyriproxyfen e spinetoram. Entretanto, foram verificadas diferenças significativas na sobrevivência de populações de B. salubricola ao novaluron (3,3% de sobrevivência) e de G. molesta aos inseticidas phosmet e tebufenozide, com 2,5 e 4,5% de sobrevivência, respectivamente. Portanto, a frequência de resistência de B. salubricola e G. molesta ainda é baixa aos inseticidas avaliados. Com base nos marcadores mitocondriais e microssatélites foi possível detectar estruturação genética significativa entre as populações de G. molesta que infestam as culturas da macieira e pessegueiro, com indicação de estruturação em função de hospedeiros (?ST = 0,198; P < 0,05) e da distância geográfica (r=0,545; valor de p<0,001). Em geral, a variabilidade genética de G. molesta foi bem distribuída nas regiões produtoras de maçã e pêssego e as barreiras geográficas, as condições edafoclimáticas e o manejo da praga parecem estar limitando o acasalamento entre os indivíduos das populações distintas avaliadas. Portanto, devido ao baixo fluxo gênico entre as populações de G. molesta, as estratégias de manejo da resistência podem ser implementadas no âmbito local para essa praga. / The apple leafroller Bonagota salubricola (Meyrick, 1937) and Oriental fruit moth Grapholita molesta (Busck, 1916) are two of the most important pests of temperate fruit trees in Brazil. Management of these both insect pest has been conducted almost exclusively with insecticides. For the implementation of proactive resistance management strategies, it is important to know the current status of pest susceptibility to insecticides to detect the resistance before control failures with the use of insecticides. In Brazilian conditions, where apple and peach orchards are very often planted close in some regions, it is believed that G. molesta may disperse to apple orchards after harvesting peaches, depending on the spatial and temporal proximity of orchards. Therefore, the objectives of this study were to characterize the susceptibility of B. salubricola and G. molesta to the main insecticides recommended for their control and to evaluate the genetic structure of G. molesta populations from the apple and peach orchards in Brazil. B. salubricola populations were collected in apple orchards in the State of Rio Grande do Sul (2011/12 growing season) and G. molesta populations from orchards in Rio Grande do Sul (2010/11 and 2011/12), Santa Catarina (2010/11) and São Paulo (2010/11 and 2011/12). There were no differences in the susceptibility among field populations of B. salubricola in compared to the susceptible reference population to the insecticides chlorantraniliprole, phosmet, spinetoram, spinosad and tebufenozide and among G. molesta populations to chlorantraniliprole, metaflumizone, pyriproxyfen and spinetoram. However, there were significant differences in survival of B. salubricola populations to novaluron (3.3% survival) and G. molesta populations to insecticides phosmet and tebufenozide, with 2.5 and 4.5% survival, respectively. Therefore, the frequency of resistance of B. salubricola and G. molesta is still low to insecticides evaluated herein. Based on mitochondrial and microsatellites markers, significant genetic structure among G. molesta populations was detected based on the host plant (?ST = 0,198; P < 0,05) and the geographic distance (r=0,545; valor de p<0,001). In general, the genetic variability of G. molesta is well distributed in the producing regions of apple and peach and the geographic barriers, soil and climatic conditions and pest management can be limiting the mating among individuals from distinct populations evaluated in this study. Therefore, due to low gene flow among G. molesta populations in Brazil, resistance management strategies can be implemented at local level.