Dissertations / Theses on the topic 'Cyhalothrin'

Helicoverpa armigera is a polyphagous pest. Due to excessive use of insecticides, the field populations of H. armigera have become resistant to synthetic pyrethroids by one or combination of three mechanisms
reduced penetration through the cuticle, decreased nerve sensitivity and enhanced metabolism by the detoxification enzymes especially glutathione S-transferases. In this study, gut sections of H. armigera were obtained from Adana and Antalya field populations and susceptible populations from Israel. Each gut section was homogenized separately in 1.0 ml, 40 mM and pH 7.5 phosphate buffers. GST activity was determined using CDNB as substrate. Product formation linearly increased up to 29.5µ
g proteins in 20mM, pH 7.5 phosphate buffers. Maximum reaction rate was reached at 30&
#9702
C. The Vmax and Km values for GST towards CDNB and GSH were calculated with Lineweaver-Burk and Eadie-Scatchard plots as CDNB Vmax
6.54µ
mol/min/mg, 6.35µ
mol/min/mg , Km
0.29mM, 0.28mM ,respectively and as GSH Vmax
6.42µ
mol/min/mg, 6.65µ
mol/min/mg, Km
0.22mM, 0.23mM, respectively. Cytosolic GST activity of each individual from Adana, Antalya and susceptible populations were determined under optimized conditions. The mean of GST activity in Adana population (n=50) and Antalya population (n=50) were found 7.824µ
mol/min/mg and 9.518µ
mol/min/mg, respectively. The mean of GST activity in susceptible population (n=50) was determined as 3.272µ
mol/min/mg. According to these results, GST activities of Adana and Antalya field populations&rsquo
showed statistically significant increase (p<
0.05) than susceptible H. armigera populations with ANOVA method. In addition, Antalya population showed statistically increase (p<
0.05) GST activity than Adana.

Organophosphates (OPs) and Pyrethroids (PYRs) are widely used pesticides in both agricultural and non-agricultural environments. In agricultural work settings, typically more than one pesticide is used in combination, or sequentially, to kill pests. There is currently a gap in research that looks at how exposures to multiple pesticides can impact human health – particularly among adolescents who work in these environments. The goal of this dissertation research was to examine the use of OP (chlorpyrifos, and profenofos) and PYR (λ-Cyhalothrin, α-Cypermethrin) pesticides across an application season and how exposure is associated with symptoms and cholinesterase enzyme activity, and to examine the impact of a sequential exposure to multiple OPs, and exposure to both OPs and PYRs. Urine and blood samples, questionnaire data, and a medical exam were collected over a 10-month period from adolescent pesticide applicators in Egypt. Overall, applicators had higher exposure than non-applicators to all four pesticides. The non-applicators were also exposed and had levels 4 times higher in urine metabolite levels than the general population in the U.S. In addition, these exposures caused increased symptoms and severity of symptoms among both applicators and non-applicators. In conclusion, adolescent agriculture workers in the Egyptian cotton fields are exposed to multiple pesticides and are susceptible to the impact of those exposures on their health.

Os custos adaptativos associados à resistência de insetos a inseticidas podem ser explorados mediante a integração com outras estratégias de controle de pragas em programas de Manejo Integrado de Pragas (MIP). No presente estudo, objetivou-se verificar custos adaptativos associados à resistência de Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) ao inseticida piretroide lambda-cyhalothrin e suas implicações na utilização do hospedeiro pelo parasitoide larval Campoletis aff. flavicincta (Hymenoptera: Ichneumonidae) e as interações com milho geneticamente modificado (MON810) que expressa a proteína Cry1Ab de Bacillus thuringiensis Berliner (milho Bt) e na resposta imunológica ao parasitismo por Campoletis aff. flavicincta. Foram verificados presença de custos adaptativos associados à resistência de S. frugiperda a lambda-cyhalothrin, dado o prolongamento no desenvolvimento larval e duração pupal, redução do peso de pupas fêmeas e longevidade das fêmeas, razão sexual, taxa líquida de reprodução (Ro), taxa intrínseca de aumento (rm) e taxa finita de aumento () de insetos resistentes ao inseticida. Não foi verificada diferença na aceitação de lagartas de S. frugiperda suscetível e resistente a lambda-cyhalothrin por Campoletis aff. flavicincta. Entretanto, o parasitismo de lagartas resistentes foi maior que de suscetíveis em estudos de gaiolas com milho Bt e não-Bt. Posteriormente, foram conduzidos estudos para avaliar, por PCR em tempo real, a expressão diferencial de genes associados ao metabolismo (proteína rica em metionina), resposta imunológica (calreticulina, lisozima, colágeno IV-2, hemócito protease-3, serina protease, imunolectina, receptor scavenger classe C) e detoxificação de xenobióticos (glutationa-S-transferase 145 e as monoxigenases P450 Cyp9A31 e Cyp333B2) expressos em diferentes tecidos (tecido adiposo, hemócitos e/ou mesêntero), na ausência e presença de parasitismo de lagartas das duas linhagens de S. frugiperda por Campoletis aff. flavicincta. No geral, a expressão gênica em lagartas suscetíveis foi superior àquela de lagartas resistentes a lambda-cyhalothrin, independente do período de desenvolvimento, do tecido avaliado e da presença ou não do parasitismo por Campoletis aff. flavicincta. E por fim, foram conduzidos estudos para avaliar o efeito da resistência de S. frugiperda a lambda-cyhalothrin nas respostas imunológica celular (contagem total de hemócitos) e humoral (atividade das fenoloxidases, lisozimática e antimicrobiana e concentração de óxido nítrico) de lagartas, tanto na ausência como na presença do parasitismo por Campoletis aff. flavicincta. A resistência de S. frugiperda a lambda-cyhalothrin induziu somente a pequenas alterações no sistema imunológico do hospedeiro (aumento do número total de hemócitos, redução da atividade antimicrobiana e aumento da atividade lisozimática), as quais não interferem a ponto de resultar em custos adaptativos que leve à maior exploração de lagartas resistentes na presença do parasitismo por Campoletis aff. flavicincta. Portanto, o manejo de S. frugiperda mediante o emprego da tecnologia de milho Bt e do controle biológico via parasitoide Campoletis aff. flavicincta pode favorecer o restabelecimento da suscetibilidade de S. frugiperda a lambda-cyhalothrin.
Fitness costs of insect resistance to insecticides can be exploited by integrating other pest control strategies in Integrated Pest Management (IPM) programs. The objective of this research was to evaluate the existence of fitness costs associated with the resistance of Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) to the pyrethroid insecticide lambda-cyhalothrin and their implications for host use by the larval parasitoid Campoletis aff. flavicincta (Hymenoptera: Ichneumonidae) and interactions with the genetically modified maize (MON810) that expresses Cry1Ab toxin of Bacillus thuringiensis Berliner (Bt maize) and in the immune response to parasitization by Campoletis aff. flavicincta. Fitness costs associated to resistance of S. frugiperda to lambda-cyhalothrin were detected by the delay in larval and pupal development, reduction in the pupal weight and longevity of females, sex ratio, net reproductive rate (Ro), intrinsic rate of natural increase (rm) and the finite rate of increase (). No differences were detected in host acceptance and survival of Campoletis aff. flavicincta in susceptible and lambda-cyhalothrin-resistant larvae of S. frugiperda. However, larval parasitization was higher on the resistant than on the susceptible strain of S. frugiperda in cage studies with Bt and non-Bt maize plants. Then, studies were conducted by using Real time-PCR to evaluate the differential expression of genes associated with metabolism (methionine-rich protein), immune response (calreticulin, lysozyme, collagen IV-2, protease-3 hemocyte, serine protease, immunolectin, scavenger receptor class C) and xenobiotic detoxification (glutathione-S-transferase 145 and P450 monooxygenases Cyp9A31 and Cyp333B2) expressed in different tissues (fat body, hemocytes and/or midgut), in the absence and presence of larval parasitization of both strains of S. frugiperda by Campoletis aff. flavicincta. Overall, gene expression in susceptible larvae was higher than that of lambdacyhalothrin- resistant larvae, regardless of the period of development, tissue evaluated and presence or not of parasitization by Campoletis aff. flavicincta. Finally, studies were conducted to evaluate the effect of the resistance of S. frugiperda to lambda-cyhalothrin on cellular (total hemocyte count) and humoral (phenoloxidases, lysozyme and antimicrobial activities and nitric oxide concentration) immune responses in the absence or presence of parasitization by Campoletis aff. flavicincta. The resistance of S. frugiperda to lambdacyhalothrin conferred only minor changes in the host immune system (increased total hemocyte count, reduced antimicrobial activity and increased lysozyme activity), which may not interfere with fitness costs leading to higher exploitation of resistant larvae in the presence of parasitization by Campoletis aff. flavicincta. Therefore, the management of S. frugiperda by using the Bt maize technology and the biological control via parasitoid Campoletis aff. flavicincta can favor the resetting to susceptibility of S. frugiperda to lambda-cyhalothrin.

Os piretróides sintéticos, em especial os do tipo II, como a cialotrina, são extensivamente utilizados para o controle de uma ampla variedade de ectoparasitas que acometem os animais de produção. Entretanto, no Brasil e em outros países, sua utilização vai além da saúde animal, sendo utilizados também em saúde pública, no controle de diversos vetores, como é o caso do vetor da dengue, dentre outros. Visto que a cialotrina modifica a atividade de macrófagos peritoneais, o objetivo deste trabalho foi investigar os prováveis mecanismos através dos quais este piretróide modifica a atividade destas células. Os presentes resultados, analisados em seu conjunto, mostram de maneira inequívoca que a cialotrina tem um efeito direto e/ou indireto sobre a atividade de macrófagos peritoneais. Especificamente, observou-se neste trabalho que o praguicida causou em ratos: 1 ? marcação fos positiva em neurônios do núcleo paraventricular do hipotálamo (NPH), após a dose de 3,0 mg/kg/dia; 2 - diminuição do percentual e intensidade de fagocitose de macrófagos peritoneais ativados e avaliados por citometria de fluxo; 3 - diminuição dose-dependente da produção de nitrito (NO2); 4 ? diminuição do percentual e intensidade de fagocitose de macrófagos peritoneais ativados, em ratos adrenalectomizados e/ou tratados com metirapona (inibidor da síntese de corticosterona) e RU 486 (antagonista de receptores glicocorticóides) com a finalidade de modular os níveis de glicocorticóides, e tratados com 3,0 mg/kg/dia de cialotrina; 5 ? aumento dos níveis de noradrenalina hipotalâmica em animais tratados com a dose de 3,0mg/kg/dia de cialotrina; 6 - diminuição do percentual e intensidade de fagocitose, bem como diminuição da produção de nitrito de macrófagos peritoneais ativados, em ratos simpatectomizados químicamente com 6-OHDA; 7 - diminuição dose dependente do percentual e intensidade de fagocitose, bem como da produção de nitrito de macrófagos peritoneais ativados e tratados in vitro com 10 e 100 nM de cialotrina. No entanto, não observamos: 1 ? alterações na produção de nitrito realizada por macrófagos peritoneais ativados, em ratos adrenalectomizados e/ou tratados com metirapona e RU 486; 2 - alterações na viabilidade celular induzida pelo tratamento in vitro com a cialotrina na concentração de 10 e 100 nM e 3 ? alterações nos efeitos da cialotrina sobre a atividade de macrófagos tratados in vitro com os ligantes de receptores benzodiazepínicos periféricos. Em conjunto, os presentes dados mostram que a cialotrina interfere com a atividade de macrófagos por atuar indiretamente, através da ativação do eixo Hipotálamo-Hipófise-Adrenal (HHA), e/ou diretamente sobre os mesmos modulando sua atividade. É muito provável que o efeito resultante do tratamento in vivo com este praguicida esteja ligado à somatória destas ações
Synthetic pyrethroids, particularly those of type II, such as cyhalothrin, are extensively used in agriculture for the control of a broad range of ectoparasites in farm animals. However, in Brazil and some other countries, these pyrethroids have also been used in public health, for the control of insects that are known to be vectors of diseases such as dengue. Since it has been suggested that cyhalothrin alters activity of peritoneal macrophages, the objective of our study was to investigate the putative mechanisms for the changes induced by pyrethroid in these cells. The results presented here show, in an unequivocal manner, that cyhalothrin has a direct or indirect (or both) effect on the activity of peritoneal macrophages. We specifically observed in this work that this pesticide induced in rats: 1- Fos-positive immunostaining in neurons of the paraventricular nucleus of the hypothalamus (NPH), after 3.0 mg/kg/day; 2 ? a reduction in the percentage and intensity of phagocytosis by activated peritoneal macrophages, evaluated by flow cytometry; 3 ? a dose-dependent reduction in nitrite production (NO2); 4 ? a reduction in the percentage and intensity of phagocytosis by activated peritoneal macrophage from adrenalectomized rats treated or not with metirapone (inhibitor of corticosterone synthesis) or RU 486 (antagonist of glicocorticoids receptors) with the propose of modulating the levels of glicocorticoids, and treated with 3.0 mg/kg/day of cyhalothrin; 5 ? an increase in the hypothalamic levels of noradrenaline in rats treated with 3.0 mg/kg/day of cyhalothrin; 6 ? a reduction in the percentage and intensity of phagocytosis and also a decrease in the production of nitrite by activated peritoneal macrophages, after chemical sympatectomy with 6-OHDA; 7 ? a dose-dependent reduction of the percentage and intensity of phagocytosis, and also a decrement in nitrite production by activated peritoneal macrophages treated in vitro with 10 and 100 nM of cyhalothrin. However, we found no differences on: 1 ? nitrite production by activated peritoneal macrophages after adrenalectomy, treated or not with metirapone or RU 486; 2 ?cell viability of peritoneal macrophages treated in vitro with 10 and 100 nM of cyhalothrin, and 3 ? the effects of cyhalothrin on macrophage activity after in vitro treatment with peripheral benzodiazepine receptor ligands. Altogether, the present results show that cyhalothrin interferes with the activity of peritoneal macrophages by acting indirectly, via activation of the hypothalamus-pituitary-adrenal axis, or directly on these cells, altering their activity. As a matter of fact, it is quite possible that the results of in vivo cyhalothrin treatment on macrophage activity would be related to the combined effect of these direct and indirect influences

Despite advances in mosquito management, mosquito-borne disease in the United States is still of relevant public health concern and vector control is a top priority in preventing transmission of pathogens. Insecticide barrier sprays have become a common tool for suppression of mosquitoes in single-homeowner backyards. The application of the synthetic pyrethroid, lambda-cyhalothrin to perimeter vegetation with a backpack sprayer has been shown to significantly suppress mosquito levels for around 6 weeks. In an attempt to lengthen the effective duration of treatment, the IGR, pyriproxyfen, was added to a backpack mist blower with lambda-cyhalothrin, as adult mosquitoes exposed to pyriproxyfen have been shown to disseminate it to oviposition sites and to experience lowered fecundity. This treatment was compared to lambda-cyhalothrin alone and to a water control. Mosquito populations were sampled using CO2-baited CDC light traps, CDC gravid traps, human landing rates, and ovitraps. Leaf bioassays were performed. The following summer, the same treatments were applied with a truck-mounted mist blower to tree lines in Central Kentucky, to test the efficacy of an application method that could be used on large properties. Finally, bioassays were performed with water sampled from pyriproxyfen-treated containers, exposed to field conditions to test for residual efficacy.

A randomized block experiment was conducted in cabbage fields at Texas Agriculture Experiment Station at Weslaco in the spring and fall 2005 and spring 2006. There were four blocks and two pesticide treatments, spinosad (SpinTor®), lambda- cyhalothrin (Warrior®), and an untreated control. The pesticide treatments were for the management of Plutella xylostella L. (Lepidoptera: Plutellidae) and Trichoplusia ni (Hubner) (Lepidoptera: Noctuidae). Pitfall traps captured eight families of spiders in fall 2005, and thirteen families in spring 2006. The most abundant family was Lycosidae with Pardosa delicatula (Gertsch and Wallace) followed by Pardosa pauxilla (Montgomery) and Hogna helluo (Walckenaer) in fall 2005, while in spring 2006 Hogna helluo was most abundant followed by Pardosa delicatula and Pardosa pauxilla. The diversity of spiders in fall 2006 in the lambda-cyhalothrin plots was lower than that of spiders found in the untreated control or the spinosad treated plots, which were up to 2.6 and 2.4 times, respectively, more diverse. In spring 2006, the spiders in untreated control and spinosad treated plots were 1.5 and 1.3 times respectively more diverse than spiders in the lambda-cyhalothrin treated plots. In fall 2005, mean diversity of spiders in spinosad treated plots was 1.1 times more diverse than in the untreated control, although this difference was not statistically significant. In spring 2006, spinosad treated plots had 1.2 times greater diversity than untreated control and this difference was significant. The effects of two insecticide treatments on height, width, and weight of cabbages were highly significant in all three seasons. Cabbage harvest in spinosad and lambda- cyhalothrin plots showed greater height, width, and weight than in untreated control but were not different from each other. However, in the larval damage rating, spinosad treatment showed better management of diamondback moth and cabbage looper than lambda- cyhalothrin.

碩士
國立屏東科技大學
植物醫學系所
104
In recent years, Cnaphalocrocis medinalis (Lepidoptera: Pyralidae) become an important pest on the rice of second phase in Taiwan. Application of insecticides was the main method to control this insect, but the resistance to various kinds of insecticides has been documented in Taiwan and other countries. This study investigated the susceptibility of C. medinalis from Changjhih and Houbi to eight insecticides. The results showed that both populations developed resistance to cyhalothrin, and the Changjhih population showed additional resistance to cartap. The synergist test was used to determine whether detoxification enzymes were involved in the metabolic resistance to cyhalothrin and cartap. When C. medinalis of Changjhih and Houbi populations were treated with cyhalothrin and three synergists individually, these two populations synergistic ratio of 285 and 606.8 for piperonyl butoxide (PBO), 1.74 and 5.4 for Diethyl maleate (DEM), 2.21 and 7.53 for Triphenyl phosphate (TPP), respectively. In addition, synergism of cartap and PBO was observed in Changzhi population, and the synergistic ratio was 3.64. Further analysis about detoxification enzymes activity treated with cyhalothrin or cartap at different concentrations for C. medinalis, biochemical assay showed cytochrome P450 activity increased significantly for Changzhi population after exposure 1ppm cyhalothrin, however, the degree of esterase and GST activity increased at higher concentration of cyhalothrin. Besides, elevation of cytochrome P450 activity of Houbi population with the concentration increasing, but esterase activity was significantly reduced. The result showed cytochrome P450 and esterase activity significantly decreased in Houbi population after exposure to cartap. Effect of C. medinalis by cyhalothrin and synergist simultaneously on the three detoxification enzymes was analyzed further. The results displayed when one synergist inhibited the activity of one specific enzyme, other detoxification enzymes were also affected. Above results concluded all three kinds of detoxification enzymes are involved in metabolism of cyhalothrin for C. medinalis, and cytochrome P450 is the major detoxification enzyme in the metabolism of cyhalothrin and Cartap. Therefore, P450-related gene mRNA expression measured detected further. Real-time quantitative RT-PCR showed that the levels of both CYP9A38 and CYP6CV1 mRNA were increased by cyhalothrin. Furthermore, previous studies reported that three point mutations (L1014F、M918T及T929I) in the voltage-gated sodium channel, and the presence of Wolbachia and alternative splicing exclusive exon G1/G2 might mediate the resistance of insect to pyrethroids. Our study indicated three point mutations were no found in these two populations. Frequencies of Wolbachia were 30% and 40% in Changjhih and Houbi, and frequencies of alternative splicing exon G2 were 70% and 40% in Changjhih and Houbi, respectively. Statistic analysis showed that no significant relationship with frequency of Wolbachia and exon G2 for resistance to cyhalothrin in these two populations of C. medinalis. The overall results are show Degrees of difference of cyhalothrin resistance from two poplution that appear correlation with synergistic test by the PBO, detoxification enzyme activity and mRNA expression (CYP9A38, CYP6CV1).

Dissertação de Mestrado em Ecologia, apresentada ao Departamento de Ciências da Vida da Faculdade de Ciências e Tecnologia da Universidade de Coimbra.
To identify potential risks derived from changing climatic regimes has become a major concern worldwide. Alterations of rain patterns are expected to modify the environmental responses of biological communities in soil, often due to alterations in moisture levels, a key factor for soil microarthropods. Pesticide use imposes great disturbances to soil, altering its functional dynamics. Since environmental conditions such as rain and temperature regimes can interfere with chemical speciation and/or chemical’s persistence in soil, soil organisms might be affected in a different way in contaminated soil under different climatic scenarios. Lambda-cyalothrin is a pyrethroid insecticide widely used to control insect pests for public health and cultivated lands. Annual agricultural use of L-cyalothrin has increased over the last years, while insecticide residuals have been detected in irrigation and storm-runoff water, and associated sediments as well. The potential risk of this pesticide to aquatic organisms is known to be high, but its effects on terrestrial communities remain practically unknown. Moreover, to date, the combined effect of changes on rain patterns and L-cyhalothrin application has not been investigated. Aiming to fill this gap, a semi-field experiment was performed using Terrestrial Model Ecosystems (TMEs). The effect of different doses of the commercial formulation of Judo® insecticide, containing L-cyalothrin as active ingredient (a.i.), was evaluated in soil fauna communities of a pasture field free of pesticide applications for more than 5 years. Doses of 0, 7.5 and 37.5 g of a.i./ha were investigated, equivalent to 0, 1 and 5 times the recommended dose, respectively. Three replicates per test dose were exposed to different rain regimes to reach moistures corresponding to 30, 50 and 70% of the water-holding capacity of the field soil. After 2 and 8 weeks of insecticide application, soil samples were collected to characterize soil fauna communities (microarthropods, nematodes, enchytraeids and earthworms). In this study only the results of mites and Collembola are shown. These data, although with high variability, suggest that toxicity levels derived from L-cyalothrin applications may be influenced by rain regime and that composition of soil mesofauna communities may be a good indicator of the influence of pesticides along time under changing climatic conditions

Resistence population of pollen beattle on selected locations of Moravia and Silesia were observed during the 2017. Beattles were taked off in the field during spring and their sensitivity to insecticides active substances indoxacarb, chlorpyrifos, thiacloprid, tau-fluvalinate, cypermethrin and lambda-cyhalothrin were tested in laboratory. Tested using methods of IRAC – 11, 21, 25 and 27. Mortality of beattles at various concentrations of active substances was evaluated after 24 hours. Levels of resistance were changed for individual location.

My thesis is devoted to the resistance of pollen beetle (Meligethes aeneus, son. Brassicogethes aeneus Fabricius, 1775) to pesticides in selected localities in southern Moravia. Collecting adults was performed in the spring of 2013 by tapped into polyethylene bags. Adults are collected from the stands of oilseed rape, mustard and poppy. Tests were performed on the basis of the methodology of Insecticide Resistance Action Committee number 011, 021, 025. In total, we tested the pollen population from 18 locations. For testing, we used the following chemical substances: Biscaya 240 OD, cypermethrin, lambda-cyhalothrin, tau-fluvalinate, etofenprox, chlorpyrifos(ethyl). We evaluated 100% of the registered dose of pesticides after 24 hours. From the results of the individual populations, we found large differences in resistance to chemicals.