Thesis (MSc)--Stellenbosch University, 1992. / One copy microfiche. / ENGLISH ABSTRACT: The effects of synthetic pyrethroids on the spider mite, Tetranychus urticae Koch, and its natural enemies was investigated. The pyrethroid cyfluthrin, sprayed for the control of fruit weevil Phlyctinus callosus, did not cause mite outbreaks and was not harmful to the predators when sprayed before they appeared on the apple trees. This spray also gave good control of thrips, bollworm (Heliothis armigera) and fruit weevil (P. callosus). A late season spray of deltamethrin against codling moth, caused an increase in the phytophagous mite population. This was assosiated with a temporary reduction in the population level of the predatory beetle, Oligota fageli. The plants found on the orchard floor were examined. The plant diversity was low and plants that acted as hosts of phytophagous mites during the winter were scarce. However, Solanum nigum carried high mite populations and infected the adjacent apple trees. The plants were too few to have an effect on the whole orchard. Eight synthetic pyrethroids were tested for repellency in a leafdisk dip and spray bioassay using T. urticae. Deltamethrin and fenvalerate caused no walk-off. Cyfluthrin and fluvalinate caused moderate walk-off and bifenthrin, cyhalothrin and lambda-cyhalothrin caused high walk-off. / AFRIKAANSE OPSOMMING: Die invloed van sintetiese piretroIedes op die rooispinmyt, Tetranychus urticae Koch en hul natuurlike vyande is ondersoek. Die piretroIed, cyfluthrin, gespuit vir die beheer van snuitkewer, P4ctinus callosus, het the mytuitbrake veroorsaak the en was ook the skadelik vir predatore nadat dit vroeg in die seisoen, voordat myte in die appelbome verskyn het, gespuit is the. Die bespuiting het ook goeie beheer van blaaspootjies, bolwurm (Heliothis amdgera) en P. callosus gegee. Deltametrien wat later in die seisoen toegedien is vir die beheer van kodlingmot, Cydia pomonella, het 'n mytuitbraak veroorsaak. Dit word geassossieer met die tydelike onderdrukking van die populasievlak van die predatoriese kewer, Oligota fageli. Die plante in die dekgewas is ondersoek. Die plant-verskeidenheid was laag en plante wat kon dien as oorwinterings gashere vir fitofage myte kon dien was skaars. Solanum nigrum het egter groot bevolkings myte gedra wat die appelbome naaste aan hulle eerste besmet het. Daar was egter te min van hierdie plante om 'n invloed op die hele boord te he. Agt piretroIedes is vir afwering van T. urticae in 'n blaarskyf doop en spuit bioessal getoets. Deltamethrin en fenvalerate het geen afwering getoon the. Cyfluthrin en fluvalinate het 'n redelike afwering, terwyl bifenthrin, cyhalothrin en lamda-cyhalothrin het 'n hod mate van afwering getoon

No description available.

The thesis deals with molecular detection of resistance in populations of pollen beetle based on genetic polymorphisms in the VSSC gene of this pest. Population samples were collected in 2016-2018 in the Czech Republic, mainly in the Southwestern Bohemian Region. A total of 57 populations of pollen beetles with different degrees of resistance were analyzed. Nucleotide mutations of populations were monitored in two parts of the VSSC gene of pollen beetles - DIIS4 - S5 linker / DIIS5 and DIIIS6 gene, which is located in the VSSC binding domain. These parts were amplified and sequenced by the Sanger method. In the alignment of final sequences, mutations were searched. After that, the effect of these mutations on the amino acid sequence was determined and the effect on the resulting VSSC protein conformation was assessed.

Made available in DSpace on 2017-07-25T19:31:03Z (GMT). No. of bitstreams: 1 Fernanda Wagner.pdf: 2201127 bytes, checksum: 1f084a627bdbb8e6aed48d44eac35a00 (MD5) Previous issue date: 2017-04-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Soybean is one of the most cultivated crops in the country, and the stink bugs of the largest losses in productivity. The Neotropical brown stink bug Euschistus heros cause severe damage to soybeans, however the green belly stink bug Dichelops melacanthus cause severe damage to corn and wheat, and can also attack soybeans. For its control, seed treatment can be performed, as in the case of D. melacanthus, or sprays with insecticides. The objective of this work was to determine the feasibility of conducting ingestion biossays in E. heros and D. melacanthus, as well as to determine the mode of action of the insecticides used to control the E. heros stink bug. The feasibility of ingestion bioassays on E. heros and D. melacanthus with systemic inseticides was investigated, as well a topical bioassay with synergistic substances on E. heros to determine the mode of action of the most common recommended insecticides. The insects used in the bioassays were collected in Cândido Mota-SP, Palmital-SP, Pedrinhas Paulista-SP and Sertaneja-PR. The data obtained were analyzed by ANOVA and Probit analysis. The CL50 for E. heros for the thiametoxam + lambda cyhalothrin mixture was (0.038 + 0.028 μg iamL-1) and for D. melacanthus (0.219 + 0.164 μg de i.a.mL-1). In ingestion trials, this mixture achieved high mortality compared to the other active ingredients tested. When inoculation with the insecticide thiametoxam and the synergist piperonyl butoxide (PBO) agent was performed, the mortalities were significantly higher in the four populations tested indicating that the monooxygenases would be detoxifying the insecticide. Likewise, imidacloprid caused higher mortality when applied with the same synergist, indicating detoxification by monooxygenase enzymes. In the same way, treatments with pyrethroids (lambda-cyhalothrin and beta-cyfluthrin) and PBO caused higher or faster mortalities than the insecticide applied alone. When treatments with acephate and acephate plus diethyl maleate were performed, E. heros mortalities were faster with the synergist diethyl maleate, indicating detoxification of the insecticide by glutathione-S-transferases enzymes, mainly in the population of Sertaneja-PR. / A soja é uma das culturas mais cultivadas no país, sendo os percevejos da família Pentatomidae responsáveis por parte das maiores perdas em produtividade. O percevejo marrom, Euschistus heros, causa danos severos em soja. Por outro lado, o percevejo barriga-verde, Dichelops melacanthus, causa danos intensos em milho e trigo, podendo atacar também a soja. Para seu controle, podem ser realizadas pulverizações com inseticidas ou o tratamento de sementes, como no caso de D. melacanthus. O objetivo deste trabalho, foi determinar a viabilidade de realizar bioensaios de ingestão em E. heros e D. melacanthus, assim como determinar o modo de ação dos inseticidas utilizados para o controle do percevejo E. heros. Os insetos utilizados para o ensaio de ingestão eram provenientes do laboratório e nos ensaios de aplicação tópica, foram realizadas coletas de campo em: Cândido Mota, SP, Palmital, SP, Pedrinhas Paulista, SP e Sertaneja, PR. Os dados obtidos foram analisados por ANOVA e análise de Probit. A CL50 de E. heros para a mistura thiametoxam + lambda cialotrina calculada foi de (0,038 + 0,028 μg de i.a.mL-1) e para D. melacanthus (0,219 + 0,164 μg de i.a.mL-1), respectivamente. Nos ensaios de ingestão, essa mistura causou mortalidade elevada em comparação aos outros ingredientes ativos testados. Quando foi realizada a inoculação com o inseticida thiametoxam e o agente sinergista butóxido de piperonila (PBO) as mortalidades foram significativamente maiores nas quatro populações testadas indicando que as enzimas monooxigenases estariam realizando a detoxificação do inseticida. Da mesma forma, o imidacloprido causou maior mortalidade quando aplicado com o mesmo sinergista, indicando detoxificação por enzimas monooxigenases e/ou esterases. Os tratamentos com os piretróides (lambda-cialotrina e beta-ciflutrina) e o PBO causaram mortalidades superiores ou mais rápidas que o inseticida aplicado isoladamente. Quando foram realizados os tratamentos com acefato e acefato mais dietil maleato, as mortalidades de E. heros foram mais rápidas com o sinergista dietil maleato, indicando o envolvimento de enzimas glutationa-S-transferases, no processo de detoxificação, principalmente com níveis mais elevados na população de Sertaneja-PR.

Orientador: Leonardo Fernandes Fraceto / Resumo: O extenso crescimento da agricultura combinado com o uso intensivo de agrotóxicos tem causado preocupação com a manutenção dos ecossistemas e a produção de alimentos realmente saudáveis. Atualmente, têm-se buscado alternativas sustentáveis para produção agrícola como os inseticidas botânicos e nanopesticidas. Os inseticidas botânicos são extraídos de plantas e utilizados no controle de pragas, sendo estes considerados biodegradáveis, seguros e menos tóxicos para a biodiversidade. Eles podem ser encapsulados em nanocarreadores que aumentam sua estabilidade e otimizem o seu uso agrícola. Os nanopesticidas trazem benefícios para o ambiente e a produtividade agrícola, dos quais destacam-se a liberação modificada dos ingredientes ativos nos campos agrícolas, maior estabilidade do sistema, menor toxicidade aos seres vivos e redução do impacto ambiental. No entanto, percebe-se a necessidade de estudos de toxicidade dos inseticidas botânicos e dos nanopesticidas em organismos não-alvos, como abelhas e anfíbios que estão declinando rapidamente no mundo inteiro. O objetivo desse estudo foi preparar e caracterizar os sistemas carreadores do extrato de piretro e avaliar o efeito destes compostos em girinos de rã-touro (Lithobates catesbeianus) e abelhas (Apis mellifera Africanizada), utilizando biomarcadores de diferentes tipologias em nível subindividual e de indivíduo. O extrato de piretro encapsulado em nanopartículas (NLS+PIR) evidenciaram uma boa estabilidade físico-química em funçã... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor

Thesis (Ph. D.)--University of Texas Health Science Center at Houston, School of Public Health, 1984. / Typescript. Dissertation Abstracts International order no. 85-05173. Includes bibliographical references (leaves 79-84).

Background: Children exposed to pesticides are susceptible for neurodevelopmental disruption. Data from developing countries are scarce. Aim: Assessing long-term and recent pesticide exposure in Nicaraguan children in relation to parental pesticide use and examining potential associated neurobehavioral effects. Methods: In the first study, pre- and post-spraying urinary residues of the chlorpyrifos metabolite TCPY and diazinon metabolite IMPY were measured among 7 subsistence farmers and 10 plantation workers, and in one child per worker. In the second study, for 110 children in an agricultural village and 22 in a non-agricultural village, aged 7-9, parental pesticide use was assessed by hours of spraying and kilograms of active ingredients during pre-and-postnatal time windows, as proxies for children’s long term pesticide exposures. Urinary TCPY, 3-PBA (pyrethroid metabolite), and 2,4-D were determined in 211 samples of 74 children of the agricultural village. IQ components and total IQ (WISC-IV) were evaluated in all agricultural village children. Behavior was evaluated with the Conners’ Teacher Rating Scale-Revised: Short. Multivariate linear regression models assessed associations between long-term and recent exposure to organophosphates and pyrethroids and cognitive and behavioral scales. Results: In study 1, post-spraying urinary levels of pesticide metabolites of subsistence farmers and their children were highly correlated (r=0.85), but not those of plantation workers and their children. In study 2, a wide range of exposures was reported by parents for all pesticides and time windows. The median urinary TCPY (3.7 μg/g creatinine), 3-PBA (2.8), and 2,4-D (0.9) were comparable to other studies for TCPY and 3-PBA but high for 2,4-D. Maximum levels were the highest reported for all compounds. Prenatal use of organophosphates affected working memory, and methamidophos also verbal comprehension and total IQ. Urinary TCPY was associated with poorer working memory. Organophosphate exposures were not associated with children’s behavior. Pyrethroid exposure during the first year of life associated with poorer perceptual reasoning and behavior, and urinary 3-PBA with a number of cognitive functions and ADHD in girls but not in boys. Conclusion: Nicaraguan children in poor agricultural areas are highly exposed to pesticides, which is influenced by parental pesticide use in subsistence farms. Organophosphate and pyrethroid exposures adversely affect their neurobehavioral development.

Thesis (Ph. D.)--University of California, Riverside, 2009. / Includes abstract. Includes bibliographical references. Issued in print and online. Available via ProQuest Digital Dissertations.

Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves [224]-254). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves [224]-254). Also available on the Internet.