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1
Bydlon, Frédéric. "Synthèse et mécanisme d'action des chromènes de série précocènes." Paris 5, 1995. http://www.theses.fr/1995PA05P204.
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Malima, Robert Chikoja Munyu. "Evaluation of long lasting insecticidal materials and treatment kits and control of pyrethroid insecticide resistant mosquitoes using alternative insecticides on nets." Thesis, London School of Hygiene and Tropical Medicine (University of London), 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.536834.
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Nigond, Jacques. "Intoxications aigues par les insecticides organophosphorés : à propos de 50 cas." Montpellier 1, 1988. http://www.theses.fr/1988MON11205.
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Ngufor, C. A. "Combining unrelated insecticides for improved control and management of insecticide resistant African malaria vectors." Thesis, London School of Hygiene and Tropical Medicine (University of London), 2015. http://researchonline.lshtm.ac.uk/2124338/.
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It is now generally accepted that if nothing is done and insecticide resistance in malaria vectors especially to pyrethroids eventually led to widespread failure of current vector control strategies, the progress achieved so far in reducing the burden of malaria could be reversed. Interventions and operational tactics capable of controlling insecticide resistant malaria vector populations and delaying the evolution of resistance need to be urgently identified and properly investigated. One important insecticide resistance management strategy is to expose vector populations to a combination of unrelated insecticides. In this study I investigated the potential of this combination concept to control and manage the spread of indoor resting insecticide resistant African malaria vectors. A series of field evaluations were performed in experimental huts in selected malaria endemic sites to investigate; 1.the impact of combining non-pyrethroid IRS or wall linings with pyrethroid LLINs against malaria vector populations with different levels of insecticide resistance and 2.The efficacy of LLINs treated with a pyrethroid and an alternative compound against pyrethroid resistant mosquitoes. The capacity of the combined intervention approach to delay the spread of insecticide resistance genes was investigated via genotyping studies. I demonstrate that the use of combined interventions and mixture net with unrelated insecticides is an effective way to improve the control of pyrethroid resistance malaria vectors. However, the performance of these combinations will undoubtedly depend on the levels and type of resistance encountered. Where resistance to both insecticides exists, improved control is unlikely. While the use of single interventions would likely exacerbate resistance the combinations would be less beneficial for preventing selection of insecticide resistance when resistance genes are already well established. The impact of these findings on malaria vector control and resistance management is discussed.
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Lind, Robert. "Actions of chloronicotinyl insecticides." Thesis, University of Bath, 1999. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299849.
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Davis, Ryan Scott. "An ecological risk assessment for mosquito insecticides." Thesis, Montana State University, 2007. http://etd.lib.montana.edu/etd/2007/davis/DavisR0507.pdf.
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Lee, Jimmy Jing-Ming 1955. "Studies of Nitrogen-containing Compounds Having Pyrethroid-like Bioactivity." Thesis, University of North Texas, 1989. https://digital.library.unt.edu/ark:/67531/metadc332332/.
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During recent years most of the successful developments in pyrethroids have been primarily concerned with structural or compositional variations. As a part of our continuing interest in pyrethroid insecticides, nitrogen-containing compounds having pyrethroid-like structures were synthesized. Seven prolinate compounds, N-(substituted)-phenyl-prolinates and N-carbobenzoxy-prolinates were coupled with known pyrethroid alcohols. These structural variations which "locked in" a specific conformation between the nitrogen and chiral a-carbon in the acid moiety of fluvalinate were studied to determine the influence of certain conformations on insecticidal toxicity.
The toxicity data for the prolinate compounds showed intermediate mortality against nonresistant cockroaches. It was concluded that the conformation imposed by the proline ring portion of the esters was probably close to the favored conformation for interaction of fluvalinate-like pyrethroids with the insect receptor site.
A second series of nitrogen-containing compounds, twenty-five carbamate esters resulting from the condensation of N-isopropyl-(substituted)-anilines and N-alkyl-(substituted)-benzylamines with appropriate pyrethroid alcohols were studied for insecticidal activity. These studies were conducted on pyrethroid-susceptible houseflies. Some of the carbamate esters exhibited high toxicity when synergized by piperonyl butoxide. For example, the toxicity ( LD 50 ) of O-a-cyano-3-phenoxyfaenzyl-N-a,a-dimethyl-4-bromo-benzyl carbamate was 0.012 ug/g, which is significantly greater than that reported for the potent pyrethroid, fenvalerate.
Correlations of insecticidal activity with respect to structure and conformational factors of the carbamate esters have been made. The N-isopropyl substituent decreases insecticidal activity in the N-benzyl-derived compounds, while the N-isopropyl substituent enhances activity in the N-phenyl-derived compounds. Certain substituents on the phenyl ring of both analogs greatly affect insecticidal potency of the carbamate esters. Also, some alkyl substituents (especially, a,cx-dimethyl and a-cyclopropyl groups) on the benzylic carbon of the benzylamine series enhance toxicity. The a,a-dimethyl branching of the N-benzyl carbamate approximates the steric shape given by the gemdimethyl group for conventional cyclopropane ring-containing pyrethroids. The N-benzyl compounds are significantly synergized by piperonyl butoxide, particularly those in which the carbamate nitrogen atom is mono-substituted.
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Anjum, Farida. "Relative toxicity of insecticides to crucifer pests and their natural enemies : interaction of insecticide and insect behaviours." Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/24773.
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Pesticides remain a necessary component of many agricultural systems and used judiciously they can play an important role in Integrated Pest Management (IPM) programmes. The aim of the present study was to investigate factors influencing the differential toxicity of insecticides against a cosmopolitan insect pest of crucifer crops, the diamondback moth, Plutella xylostella, and its respective hymenopteran parasitoid, Cotesia vestalis. Such knowledge can help in the effective use of insecticides with biological control agents in IPM. Three insecticides regarded as being compatible with some natural enemies (abamectin, spinosad, indoxacarb) and a compound generally regarded as harmful to natural enemies (lambda-cyhalothrin) were examined. Similar tests were also carried out with the peach potato aphid Myzus persicae and its parasitoid Aphidius colemani due to the loss of the Cotesia vestalis culture. A comparative measure of the intrinsic toxicity of fresh deposits (Day 0) of insecticides on Chinese cabbage was determined for both pest and parasitoid species. Lambda-cyhalothrin and abamectin were the most toxic compounds against both pests and their parasitoids, while indoxacarb and spinosad were less toxic. Residual bioassays were conducted using sprayed plants maintained under glasshouse conditions for 0-28 days after insecticide application. Results indicated lambda-cyhalothrin was the most persistent compound and abamectin and spinosad the least persistent. A leaf wax stripping technique was used with bioassays to compare the distribution of insecticide residues between the epicuticular wax layer and underlying leaf tissues. Wax removal significantly reduced the toxicity of all insecticides. No-choice and choice behavioural assays were conducted for both parasitoid species with leaf discs treated with LC5 and LC50 levels of insecticides. Both parasitoids tended to avoid insecticide-treated leaves, giving preference to untreated leaves or the arena. Emergence of adult parasitoids from cocoons/mummies on insecticide-treated leaves was not significantly different from untreated controls. The results are discussed in terms of the bioavailability of insecticides to phytophagous and non-phytophagous insect species.
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Mehmet, Ceylan. "Insecticide resistance as a biomarker for migration of Culex pipiens and its exposure to insecticides in Britain." Thesis, Queen Mary, University of London, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.612578.
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Jenson, Lacey Jo. "Induction and Inhibition of a Neuronal Phenotype in Spodoptera Frugiperda (Sf21) Insect Cells." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/40929.
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Due to the increasing resistance demonstrated by insects to conventional insecticides, the need for compounds with novel modes of action is becoming more urgent. Also, the discovery and production of new insecticides is vital as regulations and restrictions on conventional insecticides become increasingly stringent (Casida and Quistad 1998). Research in this area requires screening of many candidate compounds which is costly and time-consuming. The goal of this research was to produce in vitro insect neurons from Sf21 insect ovarian cell lines, which could lead to new high throughput screening methods and a way to mass produce insect material for basic research. This study used a culture of Sf21 cells and a mixture of differentiation agents to produce viable neuron-like cells. In the presence of the molting hormone 20-hydroxyecdysone (20-HE), or insulin, in the growth medium, Sf21 cells began to express neuronal morphology, or the production of elongated, axon-like processes within 2-3 days. Maximal differentiation occurred when in the presence of 42 μM 20-HE or 10 μM insulin. Effects were maximal on day 2 for 20-E and day 3 for insulin. Insulin was more potent at day 2 for inducing differentiation (EC₅₀ = 247 nM) than 20-HE (EC₅₀ = 13 μM). In combination, 20-HE and insulin produced apparent synergistic effects on differentiation. Caffeine, a central nervous system (CNS) stimulant, inhibited induction of elongated processes by 20-HE and/or insulin. Caffeine was a potent inhibitor of 42 μM 20-HE, with an IC50 of 9 nM, and the inhibition was incomplete, resulting in about one quarter of the differentiated cells remaining, even at high concentrations (up to 1 mM). The ability to induce a neural phenotype simplifies studies with of insect cells, compared to either the use of primary nervous tissue or genetic engineering techniques. The presence of ion channels or receptors in the differentiated cells remains to be determined. If they are present, high throughput screening for new insecticides will be accelerated and made more economical by the utility of this method.Master of Science
11
Visetson, Suraphon. "Insecticide resistance mechanisms in the rust-red flour beetle, Tribolium castaneum (Herbst)." Thesis, The University of Sydney, 1991. https://hdl.handle.net/2123/26395.
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Insecticide resistance mechanisms in five strains of beetles, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) were studied using in vitro and in viva methods.
In in vitro studies, the activities of three detoxification enzymes, monooxygenases, GSH S-transferases and esterase s were optimized.
Aldrin epoxidase activity and cytochrome P450 level were used to determine the activities of monooxygenases. The model substrates, 3,4-dichloronitrobenzene (DCNB) and 1—chloro -2,4-dinitrobenzene (CDNB) were used to measure GSH S-transferase activities. Five different esterase substrates, paranitrophenyl acetate (PNPA), naphthyl acetate (ANA), phenylacetate, methyl thiobutyrate (MTB) and acetylthiocholine iodide (ATCh) were used to investigate esterase activities.
The homogenizing medium for monooxygenases studies containing potassium phosphate buffer, pH 7.5, 1 mM EDTA, 20 mM mercaptoethanol and 50% (w/w) PVPP (weight of PVPP: weight of beetles) results in no detectable cytochrome P420 and microsomes were stored in liquid nitrogen upto 100 weeks without loss of cytochrome P450 levels.
With GSH S—transferases, GSH was required in the homogenizing medium for optimal enzyme activity.
With esterases, the homogenizing medium was the same as for monooxygenases except for the MTB and BTCh assays where mercaptoethanol was omitted. In all enzyme assays, whole beetle s were used except with ATCh assays where only the head and thorax were used.
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Maloney, Sarah Elizabeth. "Microbial transformation of synthetic pyrethroid insecticides." Thesis, University of Greenwich, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292367.
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Umeda, K., C. Fredman, and R. Fredman. "Insecticides for Whitefly Control in Cantaloupes." College of Agriculture, University of Arizona (Tucson, AZ), 1996. http://hdl.handle.net/10150/214751.
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Several experimental insecticide treatment combinations were evaluated and demonstrated very good efficacy against Bemisia argentifolii [silverleaf whitefly (WF) also known as sweetpotato WF, B. tabaci]. Adults and immatures were most effectively reduced compared to the untreated check by pyriproxyfen (S-71639, Valent) treatments and fenpropathrin (Danitol®) plus acephate (Orthene®). CGA-215944 (Ciba) plus fenoxycarb (Ciba) treatments compared favorably with many of the pyrethroid combination treatments. Registered products esfenvalerate (Asana®), endosulfan (Thiodan®), cypermethrin (Ammo®), naled (Dibrom®), and oxydemeton-methyl (Metasystox-R®) complemented many of the combination treatments to reduce WF relative to the untreated check
14
Rethwisch, Michael D. "Control of Jojoba Looper by Insecticides." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/215720.
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Umeda, Kai. "Insecticides for Whitefly Control in Cantaloupes." College of Agriculture, University of Arizona (Tucson, AZ), 1997. http://hdl.handle.net/10150/221640.
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Several experimental insecticide treatments alone or in combinations were evaluated and demonstrated efficacy against Bemisia argentifolii [silverleaf whitefly (WF) also known as sweet potato WF, B. tabaci]. At each rating date following each of four applications, the number of adult and immature WF were reduced relative to the untreated check CGA-215944 (Ciba) treatment combinations were similar at each rating date and significant differences could not be distinguished between the addition of fenoxycarb (Ciba) or CGA-59205 (Ciba). Combinations of insecticides or alternating with insect growth regulators (IGR's) also significantly reduced numbers of WF adults and immatures similar to the standard treatment of bifenthrin (Capture®) plus endosulfan. A single application of pyriproxyfen (Valent) was followed by different treatments [endosulfan followed by fenpropathrin (Danitol®) plus methamidaphos (Monitor®) followed by endosulfan] at each application date. Buprofezin (Applaud®) was combined or alternated with endosulfan at each application and similar reduction of WF was observed. Pyridaben (BASF) did not adequately reduce WF adults and immatures relative to the standard treatment in this test. The Ciba compounds and single or multiple applications of the IGR's, pyriproxyfen and Applaud were highly effective in substantially reducing WF immatures and adults in this test.
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Umeda, K., G. Gal, and B. Strickland. "Insecticides for Whitefly Control in Cantaloupe." College of Agriculture, University of Arizona (Tucson, AZ), 1999. http://hdl.handle.net/10150/221658.
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In small plot field testing, the new IGR's, buprofezine, pyriproxyfen, and fenoxycarb plus CGA-215944 , offered very good reduction of the WF adults and immature stages for several weeks. Combinations of the new insecticides and alternating weekly applications were effective in minimizing WF season-long. Pyrethroids, bifenthrin and esfenvalerate plus endosulfan treatments, were effective after early applications and nymph counts were elevated after the third application. Oxydemeton-methyl and imidacloprid treatments applied weekly compared favorably with the new chemistries to reduce adults and immatures. Pyridaben applied weekly reduced adult counts relative to the untreated check but immatures increased after the third application.
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Duarte, Boaventura Debora [Verfasser]. "Characterization of mechanisms of resistance in Spodoptera frugiperda to synthetic insecticides and insecticidal proteins / Debora Duarte Boaventura." Bonn : Universitäts- und Landesbibliothek Bonn, 2021. http://d-nb.info/1231911123/34.
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Shamu, Shepherd. "The effect of removing tariffs and domestic taxes on insecticide treated nets (ITNs), netting materials and insecticides in Zimbabwe." Master's thesis, University of Cape Town, 2002. http://hdl.handle.net/11427/6952.
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Bibliography: leaves 100-103.The use of Insecticide Treated Nets (ITNs) has already proved to be a cost effective way of malaria vector control. The important emphasis now should therefore be on how to increase the accessibility and utilization of the mosquito nets through devising viable financing and promotional mechanisms that are sustainable and equitable in the long run. One way of financing ITNs that has been propounded by the Roll Back Malaria (REM) has been the issue of the reduction or elimination of tariffs and domestic taxes on ITNs and their inputs. The purpose of this study was to look at how and in what way this RBM financing policy on eliminating tariffs and domestic taxes on ITNS and their inputs would benefit the consumer given the complex nature of ITN industry operations and the consumer behaviour. The study concentrated on information gathered from net manufacturers and insecticide providers, wholesalers and retailers and some key personnel in the overall ITN industry to gather information on production, sales and marketing trends. The analysis revealed that there are indeed gains to be realized by both the consumer and the private sector if tariffs and taxes are removed, in terms of the increase in demand and supply of the product. The elimination of the 15% tariff on ITN input prices in Zimbabwe, ceteris paribus, would lead to the retail price of ITNs falling by between 4% and 12%. This would result in consumer purchases increasing by between 2% and 11%. The elimination of both taxes, other things constant, would lead to the price falling by between 4% and 23 %, leading to retail purchases increasing by between 2% and 21%. Depending on the price elasticities of demand and supply, the fall in retail prices and the consequent increase in retail purchases are quite substantial in a developing country context where incomes are very low. Sensitivity analysis using different demand and supply elasticities also showed that the elimination of tariffs and taxes on ITNs and their inputs would lead to a substantial fall in retail purchases resulting in retail purchases increasing.
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Smith, Petrina. "Development of genetically modified Heliothis baculovirus insecticides." Thesis, Oxford Brookes University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364073.
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Prosser, Philip. "Insecticides and birds : informing avian risk assessment." Thesis, University of Reading, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288675.
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VILLATTE, FRANCOIS. "Acetylcholinesterase d'insectes : resistance et sensibilite aux insecticides." Paris 6, 1998. http://www.theses.fr/1998PA066642.
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L'acetylcholinesterase est une enzyme cle au sein de l'espace intersynaptique. Elle est la cible des insecticides carbamates et organophosphores. Certaines modifications biochimiques impliquant cette enzyme sont responsables de la resistance des insectes aux insecticides. En premier lieu, nous avons etudie les modifications quantitatives : l'analyse de certaines populations de drosophiles montre une augmentation de la quantite d'enzyme dans le systeme nerveux, ce qui implique un role dans la resistance. Les modifications qualitatives sont entrainees par des mutations dans le site actif de l'enzyme. Nous avons etudie le nombre de mutations possibles pouvant entrainer la resistance, ainsi que les facteurs de selection des combinaisons de mutations au sein du meme gene. De nouvelles mutations de resistance ont egalement ete recherchees. Un volet gestion de la resistance a ete aborde en etudiant la possibilite de detecter les mutations de resistance par voie biochimique, ainsi que la possibilite de reverser la resistance. D'autre part, la sensibilite de l'acetylcholinesterase aux insecticides en fait un outil efficace de detection des polluants dans l'environnement par l'utilisation de biocapteurs. Nous avons montre que l'enzyme la plus indiquee pour cet usage etait l'enzyme de drosophile et qu'il etait possible d'augmenter sa sensibilite par mutagenese a l'interieur du site actif.
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Camerino, Eugene. "Trifluoromethyl ketones: Potential insecticides towards Anopheles gambiae." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/54015.
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Malaria continues to cause significant mortality in sub-Saharan Africa and elsewhere, and existing vector control measures are being threatened by growing resistance to pyrethroid insecticides. With the goal of developing new human-safe, resistance-breaking insecticides we have explored several classes of acetylcholinesterase inhibitors. In vitro assay studies have shown that trifluoromethyl ketones (TFK\'s) are potent inhibitors of An. gambiae AChE (AgAChE), that inhibit the enzyme by making a covalent adduct with the catalytic serine of the enzyme. However research in the Carlier group has shown that trifluoromethyl ketones bearing benzene and pyrazole cores have shown very little toxicity to An. gambiae, perhaps due to hydration and rapid clearance. Focus was directed towards synthesis of oximes, oxime ethers, and hydrazones as potential prodrugs to prevent immediate hydration and reach the central nervous system. The synthesis of various oximes, oxime ethers, and hydrazones has been shown to give cimpounds toxic to Anopheles gambiae within 3- to 4- fold of the toxicity of propoxur. However, thus far we have not been able to link the toxicity of these compounds to a cholinergic mechanism. Pre-incubation studies suggest that significant hydrolysis of these compounds to TFKs does not occur or 22 h at pH 7.7 or 5.5.
Future work will be directed towards TFKs that have better pharmacokinetic properties. Work will also be directed at synthesis of oxime and hydrazone TFK isosteres to determine the mechanism of action of these compounds.
Master of Science
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Rethwisch, Michael D., Michael Meadows, Shari Hagerman, James Thiessen, and John McGrady. "Effects of Lettuce Insecticides Applied at Planting." College of Agriculture, University of Arizona (Tucson, AZ), 1992. http://hdl.handle.net/10150/214518.
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Palumbo, John C., F. J. Reyes, L. Carey, A. Amaya, and L. Ledesma. "Interactions Between Insecticides, Spray pH, & Adjuvants." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001. http://hdl.handle.net/10150/214912.
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Studies were conducted in the laboratory to investigate how the addition of a insecticides to two sources of Colorado River water would effect the pH of spray mixtures. In addition, we were curious what the effects of various labeled concentrations of buffers, acidifiers, spreader/stickers, and foliar nutrient sprays would have on the pH of spray water. Results showed that in most cases, spray concentration remained alkaline following addition of insecticides and adjuvants, with variations occurring primarily for the OPs. Buffering agents dramatically lowed pH at concentration greater than 0.25% v/v. Studies were also designed to evaluate the knockdown and residual mortality of Success against worms when applied in an acidic spray solution. Bioassays of larval mortality on field-treated foliage showed that knockdown mortality was not affected, but residual efficacy was significantly reduced when Success was applied using acidic (pH 4.2) spray solutions.
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Umeda, Kai. "Whitefly Control with Foliar Insecticides in Cantaloupes." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2003. http://hdl.handle.net/10150/214968.
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Courier, Knack, Assail, Calypso, and Oberon treatments on cantaloupe were effective in maintaining reduced numbers of WF eggs, immatures, and adults for 30 DAT. After 30 DAT, all treatments showed that WF adult counts began to increase. Courier, Knack, Assail, Calypso, and Oberon treated cantaloupe leaves had adult WF counts of one-half or less that of the untreated check and remaining treatments. The pyrethroid plus endosulfan treatments were effective for 7 to 13 DAT in reducing immature WF. After 21DAT, the pyrethroid plus endosulfan treatments and Actara showed a greater increase in the numbers of eggs, immatures, and adults compared to Courier, Knack, Assail, Calypso, and Oberon treatments. The seasonal average number of eggs, immatures, and adults was the least on Assail treated cantaloupes. Knack, Courier, Calypso, and Oberon treated cantaloupes consistently had less eggs, immatures, and adults compared to the untreated check.
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Rethwisch, Michael D. "Control of Variegated Grape Leafhoppers by Insecticides." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/215714.
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Kerns, David L., and Tony Tellez. "Baseline Susceptibility of Cabbage Looper to Insecticides." College of Agriculture, University of Arizona (Tucson, AZ), 2000. http://hdl.handle.net/10150/220013.
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Populations of cabbage looper were collected during 1998 from 12 geographical location in the United States, and were assessed for susceptibility to six new insecticides: Alert, Avaunt, Confirm, Intrepid, Proclaim, and Success, and to a standard insecticide, Pounce. There was no detectable evidence indicating insecticide resistance to any of the new insecticides. However, variability in response to Confirm, Proclaim, and Success warrants close resistance monitoring. Cabbage looper response to Pounce was extremely variable, and there was strong evidence for the occurrence of resistance. Populations from Jackson, MS, Sunderland, MA, and Whately, MA all exhibited high levels of resistance to Pounce with resistance ratios of 90.60, 93.50, and 76.30-fold respectively.
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Hambleton, Faith Ann (Faith Ann Elizabeth). "Effect of pH on the Persistence and Toxicity of Cyfluthrin to Chironomus Tentans." Thesis, University of North Texas, 1992. https://digital.library.unt.edu/ark:/67531/metadc935772/.
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The effect of pH upon the aquatic toxicity of cyfluthrin was determined in 48 h static acute toxicity tests using 2nd instar Chironomus tentans larvae. Tests were conducted in both dechlorinated tap water and lake water of pH 8.0, 7.2, and 6.6. After 48 h, immobilized and dead larvae were removed and replaced with 2nd instar larvae to assess the persistence of toxicity. Midges were cultured in water adjusted to the pH values used in testing. Toxicity if cyfluthrin varied inversely with pH. An increase in the pH of tap water by 2 units resulted in a 2-decrease in toxicity. Toxicity of cyfluthrin also varied between tap and lake water of the same pH. EC50 values in lake water were approximately 2-3 times lower than those in tap water. Toxicity in the lake water and tap water at every pH tested was also significantly different when regression line elevations were compared. Natural waters amended with cyfluthrin were consistently more toxi to the chironomids than tap water of the same pH. Persistence of cyfluthrin at low pH also influenced chironomid behavior. Recovery of normal behavior generally began within 24 h at pH 8.0 At pH 6.0, recovery did not begin until one week after dosing. The persistence of cyfluthrin also varied with pH. Averaged across all concentrations, 30% of the initial dose remained in tap water (pH 8.0) after 48 h, compared with 45% (pH 7.2), and 75 % (pH 6.6).
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Roux, Christine. "Toxicologie environnementale d'un insecticide : études autoradiographiques de la distribution de la radioactivité chez plusieurs espèces animales traitées par la 14C-deltaméthrine." Toulouse, INPT, 1990. http://www.theses.fr/1990INPT018A.
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Le devenir de la #1#4c-deltamethrine, insecticide pyrethrinoide, a ete etudie par autoradiographie macroscopique chez plusieurs especes animales: mammiferes, oiseaux, poissons et insectes. Ce travail avait pour but d'observer des differences de distribution qui pourraient expliquer la toxicite selective de cet insecticide. La repartition de l'isotope est comparable chez les diverses especes, les plus fortes activites sont retrouvees dans le foie et le rein. Une faible activite persistant pendant au moins 8 jours est enregistree dans les graisses chez le rat et la caille. L'etude de la distribution perinatale chez le rat a mis en evidence des traces de marquage dans les organes du ftus et du nouveau-ne. L'elimination de la radioactivite dans les ufs de caille est faible et peu persistante, elle interesse principalement le vitellus. La radioactivite est assez rapidement eliminee par voie urinaire et par voies biliaire et fecale. Le systeme nerveux central n'est pratiquement pas marque. On note cependant des traces d'isotope dans cette structure chez la truite. La deltamethrine ou ses metabolites ne franchissent que tres faiblement les barrieres hematomeningee et placentaire et ne sont elimines qu'a l'etat de traces dans le lait. Chez les oiseaux, l'excretion dans les ufs s'opere dans les 24 heures qui suivent l'administration mais il s'agit d'un processus mineur. A partir d'autoradiogrammes de caille, une approche de l'evaluation quantitative de la radioactivite a ete effectuee grace a une station d'analyse d'images. En utilisant une gamme d'etalonnage, il a ete possible de mesurer des concentrations d'equivalent de produit parental dans les principaux organes de caille
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Corcellas, i. Carramiñana Cayo-Eduard. "Estudi dels insecticides Piretroides en mostres biològiques i humanes." Doctoral thesis, Universitat de Barcelona, 2017. http://hdl.handle.net/10803/462848.
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Aquesta tesi pretén donar una visió general del comportament dels piretroides en el medi ambient i, concretament en la biota salvatge. A més, com a conseqüència directa d’això, també avalua l’exposició humana a aquests insecticides.
Els piretroides són uns insecticides emprats molt comunament. El seu ús abasta des d’usos agraris i ramaders fins a domèstics. També s’han emprat sovint en control de plagues i Salut Pública, com ara amb el control de mosquits vectors de malalties com la malària o el dengue. Per últim, l’ús dels piretroides sobre els humans tampoc no és estrany, ja que les fórmules més habituals de locions anti- polls i contra la sarna, entre d’altres, contenen piretroides com a principis actius.
Aquests insecticides són sintètics o semi-sintètics. Deriven d’uns extractes naturals de flors de diferents espècies de Chrisantemum. Aquests extractes contenen piretrines que són ésters de l’àcid crisantèmic. Els piretroides, són, també, ésters d’aquest àcid que solen estar funcionalitzats. Segons si contenen un grup ciano en la posició alfa’ de l’àcid, es distingeixen els piretroides tipus I (que no contenen el grup ciano) i els de tipus II (que sí que el tenen). Aquestes molècules, són molècules amb 2 o 3 centres quirals, raó per la qual la isomeria d’aquests també és un tema important a tractar.
Durant la tesi es va desenvolupar un mètode de determinació enantioselectiu per a 6 piretroides. Fins al inici de la tesi cap mètode quiral de la bibliografia era capaç de separar tots els enantiòmers d’un piretroide. El mètode desenvolupat demostrà l’eficàcia en separar els 4 isòmers de la tetrametrina. Per contra, amb la resta de piretroides del mètode (bifentrina, ciflutrina, cihalotrina, cipermetrina i peremetrina) només els isòmers cis es podien separar enantiomèricament, mentre que els trans no es podien discriminar. A més d’aquesta metodologia, es millorà la metodologia preexistent de quantificació de piretroides, la qual fou capaç, al final de la tesi, de determinar 19 piretroides i un pesticida organofosforat (clorpirifós) en una sola anàlisi.
Un cop es tenia metodologia adequada, es mostrejar fauna salvatge. Es dividí el tipus de fauna segons el medi que habiten les espècies, a saber, medi terrestre i medi aquàtic. Les espècies de medi terrestre que es van incloure en el estudi foren aus i grans mamífers de l’Antàrtida. De les aus es mostrejaren ous. Concretament, s’analitzaren ous infèrtils d’aus del Parc Natural de Doñana. El 96% de les mostres donaren positiu a la presència de piretroides. A més de l’anàlisi de piretroides s’analitzaren els delta15N i el
delta14C, amb la finalitat de comprovar si els piretroides eren biomagnificables en la xarxa tròfica. Tot i que els resultats de isòtops estables no foren concloents, tot semblà indicar que l’exposició als piretroides venia donada per la dieta, tot i que no es biomagnificaven. En mostres de mamífers de l’Antàrtic no es trobaren nivells de piretroides detectables, la qual cosa indicà que aquests insecticides no es transporten llargues distàncies.
Del medí aquàtic s’analitzaren peixos de riu i dofins. El 100% de les mostres presentà nivells quantificables de piretroides. Els peixos mostraren que l’exposició de piretroides ha d’estar relacionada amb quelcom més que no pas el medi físic ja que individus del mateix punt de presa de mostra presentaven perfils de piretroides diferents, és a dir, que la proporció d’un piretroide respecte d’un altre era diferent segon el individu analitzat. Això podia venir donat a una metabolització selectiva d’uns piretroides o a que l’exposició fos via dieta i els animals, que pertanyien a espècies diferents, tinguessin diferents hàbits alimenticis. Pel que fa a dofins, es va trobar que tant dofins brasilers com espanyols presentaven nivells de piretroides tot i que els primers solien presentar més nivells de cipermetrina i permetrina mentre que els segons de cipermetrina i tetrametrina. També es va demostrar la transferència materna com un possible problema toxicològic per als fetus i els lactants. Finalment, es va comprovar la distribució dels piretroides en diferents teixits i es va arribar a la conclusió que el teixit adipós és on més piretroides s’acumulen, tot i que, segurament gràcies a la unió amb diferents proteïnes, en teixits magres també s’hi trobaven nivells. Amb això es preferí per a mostrejos posteriors el fetge com a matriu a analitzar o, en cas de individus vius, el teixit adipós superficial.
Respecte dels humans, es comprovà que la població general està exposada als piretroides a nivells relativament baixos. Els estudis es van fer en poblacions de Brasil, Colòmbia i Barcelona. Amb tot, donats els resultats, s’optà per aconsellar un millor control dels nivells de piretroides en llets maternes, sobretot de poblacions sobre-exposades, i una revisió dels valors de ingesta acceptables de piretroide en el cas de infants i lactants.The present Thesis is about pyrethroid insecticides. They are very used in agrarian, veterinarian and domestic environments. Besides, they are used in Public Health in order to control mosquito vectors of diseases such as malaria and dengue. They are chiral molecules, thus isomeric characteristics are important in their environmental behavior and toxicology. In this thesis, a new method for enantiomeric discrimination of 6 pyrethroids was developed. For the first time a method was able to separate all enantiomers of one pyrethorid, in this case, tetramethrin. Besides, the method was able to differentiate cis enantiomers of bifenthrin, cyfluthrin, cyhalothrin, cypermethrin and permethrin. Pyrethorids were evaluated in unfertile wild bird egg samples, Antarctic mammals, river fishes and dolphins. In 96% of bird eggs residues of pyrethroids were observed. In 100% of all the rest of matrices presented quantifiable levels of pyrethroids except for Antarctic mammal samples. First way of exposure to pyrethroids for these wild species seemed to be diet. However, no biomagnification was described. Long distance transport was discarded since Antarctic samples did not present levels of pyrethrids. Pyrethroids were mostly accumulated in lipid tissues, such as dolphin blubber. The best matrix to future monitoring was described as liver samples, even when for living individuals, superficial blubber sample could be used. Cis isomer of pyrethroids were more bioaccumulated than trans, except in the case of tetramethrin. In this last case, commercial mixtures, which are enhanced in trans isomer, could explain this observation. For the rest of pyrethroids, cis isomer was enhanced because of the preference of trans isomer in the isomer-selective metabolization of most of organisms. Regarding human exposure, breast milk samples from Brazil, Colombia and Spain were analyzed. All samples were positive in the pyrethroid determination analyses. Even when levels in general population seemed to be save, Acceptable Daily Intake values should be reconsidered for breastfed children.
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Javed, Naghmy. "How insect acetylcholinesterase has become insensitive to insecticides." Thesis, Queen Mary, University of London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398126.
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Anthony, Nicola Mary. "Action of convulsants and insecticides on GABA receptors." Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240117.
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Kou, Jinghong. "The Neurotoxicity of Insecticides to Striatal Dopaminergic Pathway." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/77991.
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Parkinson's disease (PD) is an age-related neurodegenerative disease, which is characterized by severe loss of dopaminergic neurons in the substantia nigra pars compacta (SNc) and consequent dopamine depletion in its projecting area. In this dissertation, I evaluated the neurotoxicity of several classes of insecticides/drugs/neurotoxins to the striatal dopaminergic pathway and their potential relationship to Parkinsonism in the C57BL/6 mouse model, using biochemical and molecular biology methods.
In the first objective, I investigated the neurotoxicity in striatal dopaminergic pathways following co-application of permethrin (PM), chlorpyrifos (CPF) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The study was done because pyrethroid and organophosphorus compounds are widely used insecticides and they have been implicated in Gulf War Syndrome. We found that short-term, high-dose exposure to PM or CPF had no significant effects on the expression of dopamine transporter (DAT), tyrosine hydroxylase (TH), or α-synuclein protein in striatal nerve terminals, but the insecticides slightly enhanced the neurotoxicity of MPTP in C57BL/6 mice at 28 days post-treatment. This finding indicates a slowly developing neurotoxicity may occur after termination of high-dose exposure. Long-term, low-dose exposure to PM did not show significant neurotoxicity to striatal dopaminergic pathways when given alone, nor did this injection of PM enhance the neutotoxicity of MPTP in C57BL/6 mice. In addition, experiments with pure cis or trans isomers of permethrin showed that both cis and trans isomers contributed equally to the neurotoxicity of PM in the short-term high dose study.
Previous studies demonstrated a deficiency in mitochondrial function in PD, and a high density of K⁺ATP channels are present in substantia nigra, which play an important role in the maintenance of the membrane potential under metabolic stress. Therefore, in the second objective, I investigated the effect of K⁺ATP channel blockage on the neurotoxicity of mitochondrial-directed neurotoxins to striatal dopaminergic pathways. I found that mitochondrial inhibitors are potent releasers of preloaded dopamine from striatal nerve terminals, with the most potent compounds active in the nanomolar range. Co-application of the K⁺ATP channel blocker glibenclamide selectively increased the dopamine-releasing effect by complex I inhibitors in vitro, and potentiated the neurotoxicity of MPTP (a complex I inhibitor) on DAT and TH expression, in vivo. Mechanistic studies demonstrated that mitochondrial inhibitor-induced dopamine release is Ca²⁺-dependent. In addition, the selectivity of glibenclamide is not correlated to ATP depletion, but associated with the generation of excessive reactive oxygen species at the site of complex I.
In the third objective, I conducted comparative studies on the mode of action of rotenone-/reserpine-/tetrabenzaine (TBZ)-induced depletion, in vitro, as these three compounds share some similarities in their chemical structures. I found that rotenone, reserpine and TBZ selectively released preloaded dopamine and serotonin (5-HT), with the rank order as rotenone>reserpine>TBZ. Mechanistic studies demonstrated more than one mechanism was involved in both rotenone- and reserpine-induced neurotransmitter release. Ca²⁺-stimulated vesicular release and neurotransmitter transporter-mediated release are the common mechanisms involved in rotenone- and reserpine-induced dopamine release.
Overall, the insecticides/drugs/neurotoxins tested in the above experiments all exhibited some effect on the nigrastrital dopaminergic pathway, either alone or by enhancing the toxicity of other chemicals in combination treatment.Ph. D.
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Palumbo, John C., Peter C. Ellsworth, and Timothy J. Dennehy. "Cross-commodity Guidelines for Neonicotinoid Insecticides in Arizona." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2003. http://hdl.handle.net/10150/146722.
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4 pp.Arizona enjoys a sustained recovery from the devastating whitefly outbreaks of the early 1990's. This success is built on an IPM strategy that includes the use of selective and effective chemistry. Admire has been a key soil insecticide protecting vegetables and produce throughout Arizona and is the first member of a burgeoning class of chemistry known as the neonicotinoids. New members of this valuable, reduced-risk, class of chemistry are now available to agricultural producers, placing a burden on users of these compounds to adopt rational plans for sustaining their efficacy. This consensus document represents our best guess efforts to limit and share this chemistry among different agricultural interests. Our goal is to preserve the long-term efficacy of the neonicotinoids and protect growers' interests in sustainable and economical whitefly management. Through identification of crop communities (i.e., "multi-crop", "cotton-intensive", and "cotton/melon") common to Arizona agriculture, we have sculpted sensible plans of use that should allow access to this valuable chemistry for everyone, while protecting it from resistance.
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Watson, T. F., and Clay Mullis. "Effect of Various Insecticides on Pink Bollworm Control." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/204083.
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Dennehy, T. J., J. E. Russell, L. Antilla, and M. Whitlow. "New Insights Regarding Estimating Lygus Susceptibility to Insecticides." College of Agriculture, University of Arizona (Tucson, AZ), 1998. http://hdl.handle.net/10150/210378.
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Lygus susceptibility was found to vary widely from year to year, from region to region and, for some insecticides, even within the season. It is for this reason that producers need current, region-specific recommendations in order to determine which insecticides are most effective at their locale. Our studies were intended to improve understanding of the reliability of glass vial bioassays for estimating efficacy of insecticides used against lygus bugs. Results show that the standard glass vial method offers considerable promise for detecting differences in susceptibility of lygus to some, but not all, insecticides. However, mortality in vial bioassays did not serve as a reliable predictor of the relative toxicity of residues of five insecticides in field treatments. Therefore, field evaluations of insecticide efficacy continue to be essential for selecting the insecticides that provide the best control of lygus. Once the most effective materials are selected from field trial results, bioassays can be used to efficiently monitor changes in population susceptibility to these insecticides. Additional new insights provided by our studies are that efficacy of residues of insecticides declined rapidly, such that after three days all insecticides caused very little mortality to adult lygus bugs. Lastly, we found a marked difference between residual and direct contact toxicity of the five insecticides evaluated. Even the insecticide treatments that resulted in relatively low toxicity in residual exposure tests killed 95-100% of lygus bugs that they contacted directly under field conditions. This finding indicates that producers experiencing severe problems with lygus control would be well advised to improve insecticide coverage.
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Umeda, Kai, and Chris Fredman. "Evaluation of Insecticides for Aphid Control in Cabbage." College of Agriculture, University of Arizona (Tucson, AZ), 1996. http://hdl.handle.net/10150/214743.
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Experimental insecticides CGA-215944 (Ciba), pyriproxyfen (S-71639, Valent), and RH-7988 (Rohm and Haas) demonstrated very good efficacy in reducing the aphid population in cabbage. Fipronil (Rhone-Poulenc) was not as effective in controlling the aphids relative to the other treatments. Acephate (Orthene®), chlorpyrifos (Lorsban™), and naled (Dibrom®) were highly effective relative to the untreated check.
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Umeda, Kai, and Gabriel Towers. "Evaluation of Insecticides for Efficacy on Turfgrass Pests." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2008. http://hdl.handle.net/10150/216634.
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No masked chafer larvae were observed for treatments of imidacloprid, imidacloprid plus bifenthrin, clothianidin, and the two higher rates of DPX-E2Y45. The inconsistent and low populations of masked chafer larvae and billbugs in the turfgrass did not provide for conclusive results. Clothianidin and the two higher rates of DPX-E2Y45 had no billbug larvae. An early rating date showed that more billbug adults were in turf treated with imidacloprid and DPX-E2Y45. Later rating dates showed a decline in adults for all treatments.
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Umeda, Kai. "Evaluation of Foliar Insecticides for Whiteflies in Cantaloupes." College of Agriculture, University of Arizona (Tucson, AZ), 1999. http://hdl.handle.net/10150/219967.
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A single application of buprofezin (Applaud7) at 0.38 lb AI/A had the fewest number of adult whiteflies (WF) on rating dates at 13, 21, and 27 days after treatment (DAT). The number of immature WF at 21 DAT of a single Applaud application ranged from 0.8 to 5.2 nymphs/leaf, significantly less than the untreated. Applaud treatments were effective in minimizing the immatures for 21 DAT of a single application and then numbers began to increase before 27 DAT. Applaud plus two subsequent weekly applications of bifenthrin (Capture7) plus endosulfan (Thiodan7, Phaser7) was almost similar to single applications of Applaud alone and adult numbers were also low. Weekly applications of the pyrethroids plus endosulfan reduced the adult WF relative to the untreated at 1 week after treatment (WAT). At 2 WAT of the third application, fenpropathrin (Danitol7) and Capture continued to show reduced numbers of adults and esfenvalerate (Asana7) was similar to the untreated. Danitol treatments had numerically fewer adults than Capture which was lower than Asana. The lowest adult and immature WF populations were observed season-long in the CGA-293343 (Novartis) treated cantaloupes. Both rates, 0.067 and 0.09 lb AI/A performed similarly and numerically slightly fewer nymphs were observed for the higher rate. CGA-293343 plus CGA-215944 (pymetrozine, Fulfill7) performed similar to the two rates of CGA-293343 alone.
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Umeda, K., D. MacNeil, and D. Roberts. "New Insecticides for Diamondback Moth Control in Cabbage." College of Agriculture, University of Arizona (Tucson, AZ), 2000. http://hdl.handle.net/10150/219999.
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At 3 days after the first application, RH-2485, Success, Proclaim, Avaunt, and Larvin reduced the total number of diamondback moth (DBM) larvae to less than 2.0 larvae per 10 plants compared to the untreated that had 7.0 larvae/10 plants. Alert, Kryocide, and S-1812 treated cabbage exhibited 4.0 to 5.0 larvae/10 plants and Lannate was intermediate with 2.7 total larvae/10 plants. Following a second application, Success and Proclaim completely controlled DBM for one week. Success, Proclaim, Alert, and Larvin continued to offer very good control of DBM for two weeks after the second application. S-1812 performed similarly to Lannate.
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Matos, Rosa Escórcio Pacavira. "Efeito insecticida de Tephrosia Vogelii Hook. F. no controlo de Sitophilus zeamais Motoschulski (Coleoptera: Curculionidae): uma contribuição para o desenvolvimento rural sustentável em Angola." Doctoral thesis, ISA/UTL, 2011. http://hdl.handle.net/10400.5/3862.
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Doutoramento em Engenharia Agronómica - Instituto Superior de AgronomiaThe main objectives of present work are the development of studies on the potentialities of Thephrosia vogelii substances to control infestations of Sitophylus zeamais on stores maiz in Angola. The methods most commonly used by small farmers in Malange and Huambo to the conservation of agricultural products, are fundamentally the prevention, heat, ventilation, use of wood ashes, dust and leaves from local plants.Most farmers use chilli powder (Capsicum frutescens L.) and Tephrosia spp. The powders of leaves of T. vogelii maily the doses of 1.5 and 2% w/v resulted in 90 and 80% repellency to adults of S. zeamais. With the concentration of 2% w/v, powder of seeds and leaves, caused 21,6 and 21,0% mortality respectively. Even with low mortality after the seeds and leaves treatment, a redution on G1 to 92.8 and 93.2% was observed. With the extracts of the roots, obtained by maceração, hot and cold, mortalities of 46 and 58.0% were reached witj the concentration of 1.10, while the concentration of 1:25 of the of seeds extract, caused mortalities of 82.0% and 90% respectively to hot and cold extraction conditions. The whole plant (a mixture of the several vegetative organs) at the concentration of 1:10, induced 82.0 and 90.0% of mortality both hot and cold respectively. The reduction in the emergency G1 was observed, only in the hot aqueous extracts from leaves and stem, from 56.7% to 61.1% with the concentration of 1:10. Extracts from leaves of T. vogelii obtained with organic solvents, were repellent enough. The extract in methanol and 88 caused 82% mortality, reducing the G1 in 100% at a concentration of 5%. Fumigation with essential oil concentrate, observed mortality of S. zeamais 100% at a concentration of 15 μl/ ml of oil. By diluting the oil in an organic solvent n-hexane caused (100%) mortality, higher concentrations (10 and 15 μl/cm2), corn treated with the oils dissolved in acetone caused mortality (94%) acetate ethyl (96%) and methanol (92%), causing a reduction of emergency 99- 100%-----------------------------------------------O presente trabalho tem como objectivo o desenvolvimento de estudos das potencialidades de subtâncias extraídas de Thephrosia vogelii para combate a Sitophylus zeamais em milho armazenado em Angola. Os métodos tradicionalmente utilizados pelos pequenos camponeses em Malange e Huambo, para conservação de produtos agrícolas, são fundamentalmente a prevenção, o calor, arejamento, o uso de cinzas de madeira, pós e folhas de plantas locais. A maior parte dos camponeses utilizam pós de malagueta (Capsicum frutescens L.) e Tephrosia spp. Os pós de folhas de T. vogelii a 1,5 e a 2% provocaram 90 e 80% de repelência em adultos de S. zeamais. Com a concentração de 2%, os pós de sementes e de folhas, causaram 21,6 e 21,0% de mortalidade respectivamente. Mesmo com baixa mortalidade os pós das sementes e das folhas, reduziram a descendência G1 até 92,8 e 93,2%. Os extractos aquosos das raízes, por maceração a frio e a quente, causaram mortalidade de 46 e 58,0% a 1:10 respectivamente, enquanto que as sementes a quente causaram mortalidade de 82,0% e a frio 90% a 1:25 mL. A planta inteira (mistura das partes vegetativas), na concentração de 1:10, apresentou entre 82,0 e 90,0% de mortalidade por maceração a quente e a frio respectivamente. A redução da emergência G1 somente foi observada nos extractos aquosos a quente de folhas 56,7% e do caule com 61,1% a concentração de 1:10. Os extractos de folhas de T. vogelii, obtidos com os solventes orgânicos, mostraram-se bastantes repelentes. O extracto em metanol causou 82 e 88% de mortalidade, reduzindo a G1 em 100% na concentração de 5%. A fumigação com óleo essencial concentrado, observou-se mortalidade de S. zeamais de 100% na concentração de 15 μl/ mL de óleo. Diluindo o óleo em solventes orgânicos o n-hexano causou (100%) de mortalidade, nas concentrações mais altas (10 e 15 μl/cm2). O milho tratado com os óleos diluídos em acetona, causaram mortalidade de (94%) acetato de etilo (96%) e metanol (92%), provocando uma redução de emergência de 99 a 100%
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Goindin, Daniella. "Étude des résisatances aux insecticides et des réponses biologiques aux changements climatiques du moustique Aedes aegypti, vecteur de la Denguen du Chikungunya et du Zika en Guadeloupe." Thesis, Antilles, 2016. http://www.theses.fr/2016ANTI0054/document.
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La Guadeloupe fait partie des pays où la Dengue est endémique avec des épidémies tous les 2 à 3 ans. Depuis 3 ans, d'autres arboviroses sont apparues sur le continent américain avec le Chikungunya en 2013 puis le Zika en 2015, causant d'importantes épidémies notamment en Guadeloupe. Le seul vecteur reconnu de ces maladies en Guadeloupe est le moustique Aedes aegypti. Il n'y a pas de vaccin, ni de traitements spécifiques contre ces infections et les moyens de prévention contre ces maladies passent par la surveillance et le contrôle des populations de moustiques sur le terrain. Les méthodes de surveillance sont basées le plus souvent sur l'analyse d'indices larvaires, parfois controversés. De plus, les moyens de contrôle des vecteurs ont longtemps été basés sur l'utilisation massive d'insecticides chimiques entraînant la résistance des moustiques à ces produits. Ce travail de thèse s'est donc articulé autour de deux grands axes devant permettre d'améliorer la prévention et le contrôle de ces arboviroses: i) la recherche d'un nouvel outil de surveillance des populations vectrices, basé sur la physiologie des femelles adultes et ii) l'évaluation des niveaux et l'étude de certains mécanismes de résistance à trois insecticides chimiques, le Téméphos, le Malathion (utilisés dans le passé) et la Deltaméthrine (utilisée actuellement). Un modèle de surveillance des populations vectrices basé sur les taux de parité en lien avec l'espérance de vie des femelles, en fonction des températures a été développé, et des pistes sur les situations entomologiques les plus à risques se sont dessinées. Les épreuves de résistance effectuées sur des larves de moustiques de Guadeloupe ont globalement révélé de forts niveaux de résistance au Téméphos et de faibles niveaux de résistance au Malathion. Les tests adulticides ont mis en évidence une résistance modérée des femelles à la Deltaméthrine. Les investigations moléculaires ont démontré des fréquences alléliques très élevées pour les mutations Kdr V1016I et F1534C connues pour être liées à la résistance aux pyréthrinoïdes. De plus, l'évaluation des niveaux d'expression constitutifs de certains gènes de détoxification a révélé des surexpressions significatives des populations testées par rapport à la souche sensible Bora-Bora, pour la carboxy-choline-estérase CCEAE3A, quatre cytochromes P450 à mono-oxygénases (014614, CYP6M11, CYP6BB2 et CYP9J23) et la glutathione-S-transférase GSTE2Guadeloupe is an endemic country for Dengue with epidemics every 2 to 3 years. In the past 3 years, other arboviruses have reached the Americas with Chikungunya virus in 2013 and Zika virus in 2015, causing major epidemics including in Guadeloupe. The only known vector of these diseases in Guadeloupe is the mosquito Aedes aegypti. As there is no vaccine nor specific treatment against these infections, prevention against these diseases is achieved through the monitoring and control of mosquito populations. Monitoring methods are based mostly on larval indices, with sometimes controversial results. In addition, vector control methods are based since a very long time on the massive use of chemical insecticides, causing mosquito resistance to these products. This work has therefore focused on two main areas to improve the prevention and control of these arboviruses: i) the search of a new vector population monitoring tool, based on the physiology of adult females and ii) the assessment of the resistance levels and mechanisms regarding three chemical insecticides, Temephos, Malathion (used in the past) and Deltamethrin (currently used). A vector population monitoring model based on females life expectancy as a function of parity rates and according to temperatures has being developed, and tracks on the entomological situations most at risk have emerged. Insecticide resistance tests performed on mosquito larvae have generally found strong Temephos resistance levels and low resistance to Malathion. Adulticide tests showed a moderate resistance of females to Deltamethrin. Molecular investigations have shown very high allelic frequencies for kdr mutations V1016I and F1534C, known to be associated with pyrethroid resistance. Moreover, the evaluation of constitutive expression levels of some detoxification genes revealed significant overexpression in tested Aedes aegypti populations compared to the susceptible Bora-Bora strain, for the carboxy-choline-esterase CCEAE3A, four cytochrome P450 mono-oxygenases (014614, CYP6M11, CYP6BB2 and CYP9J23) and the glutathione-S-transferase GSTE2
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Kassebaum, B. J. "Susceptibility of the black Portuguese millipede, "Ommatoiulus moreletti" Lucas (Diplopoda : iulidae) to insecticides." Title page, contents and summary only, 1985. http://web4.library.adelaide.edu.au/theses/09A/09ak19.pdf.
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Zhai, Jing. "Application of insecticides to control the German cockroach, Blattella germania (L.)." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-06102009-063046/.
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Merelli, Bérangère. "Proinsecticides chiraux d'acides carboxyliques et de β-ethanolamines : effet de la chiralité sur la métabolisation et les activités biologiques chez l'insecte." Versailles-St Quentin en Yvelines, 2004. http://www.theses.fr/2004VERS0005.
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Les D2-thiazolines et les N-acylaziridines sont étudiées comme structures de proinsecticides d'acides carboxyliques fluorés ou non. Les D2-thiazolines ont été obtenues sous forme de racémiques et d'énantiomères purs par une méthode de thionation/cyclisation en utilisant le réactif de Lawesson. Les N-acylaziridines ont été synthétisées en condensant un acide carboxylique sur une aziridine obtenue sous forme racémique et énantiomériquement pure à partir d'oxiranes. Des méthodes d'analyse chirale de RMN et HPLC ont été mises au point sur les différents substrats synthétisés pour contrôler la pureté énantiomérique et pour évaluer la composition d'extraits de milieux biologiques d'insectes incubés par des racémiques de N-acylaziridines suite à une hydrolyse enzymatique incomplète. Les propriétés biologiques des D2-thiazolines et des N-acylaziridines ont été évaluées au cours de tests effectués sur Drosophile, Puceron ou Acarien. La métabolisation des molécules les plus intéressantes a été étudiée en présence de milieu biologique d'insecte (tissus de criquet ou de chenille ou a-chymotrypsine), sans prétraitement de l'échantillon, par RMN 19F ou par HPLC avec injection directe sur des colonnes large pore et des colonnes monolithiques. En présence de ces milieux biologiques, les N-acylaziridines étudiées se comportent effectivement comme des proinsecticides d'acides carboxyliques puisqu'elles le démasquent efficacement. Les D2-thiazolines se révèlent plus stables puisqu'elles nécessitent l'utilisation de milieux biologiques concentrés pour libérer une faible quantité d'acide carboxyliqueThe nitrogen heterocylces D2-thiazoline and N-acylaziridine were studied as potential proinsecticides masking the active principles : fluorinated or not carboxylic acids. The synthesis of D2-thiazolines, either as racemates or as pure enantiomers, were performed by thionation/cyclisation using Lawesson reagent. The synthesis of N-acylaziridines were performed by condensation of carboxylic acid with amine obtained as racemate and as pure enantiomer using oxiranes. We developped analytical chiral methods of NMR and HPLC to verify optical purity of different substrates. Then, these methods were applied to extracts of incubated insect tissues by N-acylaziridines racemates after a partial unmasking for the determination of the enantiomeric composition. The biological properties of these potentials proinsecticides were evaluated by several testings performed with various pests : Drosophila melanogaster, Aphis gossypii, Myzus persicae, Tetranychus urticae. The metabolization of the most interesting molecules was studied in insect biological media (tissues of locusts or caterpillars or with a-chymotrypsin), without any pretreatment, using analytical methods such as 19F[1H]NMR or HPLC allowing the direct injection on particular packing material such as wide pore particles or monolithic column. In these biological media, N-acylaziridines beleave effectively as proinsecticides of the carboxylic acid, since the unmasking is very efficient. D2-thiazolines are more stable since it's necessary to use concentred biological media for unmasking a little of active principle
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Edney, Dean. "Synthetic studies towards guinesine and other naturally occurring sulphur heterocycles." Thesis, University of Nottingham, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284032.
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Helliwell, Raymond Michael. "The physiology of locust hindgut muscle with reference to the possible effects of azadirachtin." Thesis, University of Aberdeen, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304951.
Full textAbstract:
The physiology of Locusta hindgut has been investigated using techniques developed for measuring both contractility of whole hindguts and the electrophysiological properties of hindgut superior longitudinal (SL) muscle, in order to examine the possible interaction of the tetranortriterpenoid, azadirachtin. The pentapeptide proctolin, a neurotransmitter/modulator candidate at the hindgut neuromuscular junction, produced highly reproducible dose dependent effects on the isolated hindgut preparation. The effect of other putative neurotransmitters/modulators, including acetylcholine, 5-HT, octopamine, GABA and FMRFamide, and the effects of high potassium Ringer, calcium free (EGTA) Ringer, Co2+ and verapamil on the proctolin response, were also assessed. Neurally evoked contractions could be produced by stimulating the proctodeal nerve, using a standard set of stimulation parameters. Under these conditions, neurally evoked responses comprised both a phasic and tonic component. The effect of verapamil, Co2+ and Ca2+ free Ringer was examined on these responses. Proctolin, at low doses, did not potentiate neurally evoked responses, although a potentiation could be seen if the stimulation parameters were significantly altered. In contrast, GABA dose dependently inhibited neurally evoked responses. Both cyclic adenosine monophosphate and inositol trisphosphate pathways are implicated in the neurally evoked response. Azadirachtin, under the conditions of the experiment, did not antagonize proctolin induced contractile responses, which is in contrast to a previous study (Mordue(Luntz) and Evans 1987) and had no consistent effect on neurally evoked responses. In addition, no major differences in the contractile behaviour were found between insects injected with azadirachtin in vivo and control insects, although hindguts from the azadirachtin treated group appeared more relaxed and flaccid than those of the control group, and produced larger responses on contraction.
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Talukder, Farid A. "Isolation and characterization of active secondary pithraj (Aphanamixis polystachya) compounds in controlling stored-product insect-pests." Thesis, University of Southampton, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295906.
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Koni, Pandelakis. "Molecular characterization of Bacillus thuringiensis cytolytic delta-endotoxins." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309051.
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Lovell, Helen. "Azadirachtin : biological properties and synthetic studies." Thesis, University of Cambridge, 1994. https://www.repository.cam.ac.uk/handle/1810/272783.
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