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1.
I.E. Pérez-González M.G. Prado-Ochoa M.A. Muñoz-Guzmán V.H. Vázquez-Valadez A.M. Velázquez-Sánchez B.L. Avila-Suárez C. Cuenca-Verde E. Angeles F. Alba-Hurtado 《Veterinary parasitology》2014,199(3-4):235-241
The effects of six new synthetic carbamates on fully engorged females of four Rhipicephalus microplus strains (one reference strain susceptible to conventional ixodicides, two strains multiresistant to ixodicides and one tick field isolate) were compared. In addition, the effect of two other new synthetic carbamates was tested on larvae from the same strains. The first six tested carbamates reduced egg laying and inhibited egg hatching in the four studied strains (P < 0.05). Compared with untreated females, the eggs produced by the treated engorged female ticks of all strains had a dark, dry, opaque appearance and were less adherent. The remaining two tested carbamates induced larval mortality in all of the evaluated strains. The three studied R. microplus strains displayed 50% resistance ratios (RR50) of less than 2 when compared to the susceptible reference strain. These results demonstrate that both carbamates with a larvicidal effect and carbamates that inhibit egg laying and embryo development are efficacious against tick strains that are resistant to commercial ixodicides, no cross resistance was observed. 相似文献
2.
M.G. Prado-Ochoa M.A. Muñoz-Guzmán V.H. Abrego-Reyes A.M. Velázquez-Sánchez M. Lara-Rocha C. Cuenca-Verde E. Angeles F. Alba-Hurtado 《Veterinary parasitology》2013
The effect of carbamates on engorged female Rhipicephalus microplus ticks and larvae was evaluated using the adult immersion test (AIT) and the larval packet test (LPT), respectively. Seventeen synthetic carbamates different from current commercial acaricides were synthesised at the National Autonomous University of Mexico. None of the carbamates had an effect on the percentage of females laying eggs. Six of the compounds inhibited egg laying up to 65.4% and inhibited egg hatching by up to 100% (p < 0.05). Compared to untreated females, eggs produced by treated females had a dark, dry, opaque appearance and were less adherent. Carbamates LQM 934 and LQM 938 had an effect on larval mortality (p < 0.05). Carbamate LQM 934 showed lethal concentrations (LC) of LC90 = 0.76% and LC99 = 0.87%, while LQM 938 showed concentrations of LC90 = 0.267% and LC99 = 0.305%. The compounds were distributed into three classes of acaricidal activity using the AIT or the LPT. These three classes were as follows: (1) compounds having no apparent effect; (2) compounds that inhibit egg laying and embryo development or (3) compounds that exhibit acaricidal activity to larval ticks. 相似文献
3.
Studies were carried out to evaluate the resistance of Pakistani populations of the beet armyworm, Spodoptera litura (F) to several commonly used insecticides. Different field populations of S. litura from four districts of the Punjab were monitored from 2009 to 2011 for resistance to insecticides using a standard leaf dip bioassay method. For organophosphates and pyrethroids, resistance ratios compared with a susceptible Lab-Pk population were in the range of 8–109 fold for deltamethrin, 11–139 fold for cypermethrin, 19–143 fold for chlorpyrifos and 39–162 fold for profenofos. For new chemistry insecticides, resistance levels were 2–74 fold for spinosad, 4–216 fold for abamectin, 7–87 fold for indoxacarb, 2–77 fold for emamectin benzoate, 1.9–58 fold for lufenuron and 4–43 fold for methoxyfenozide. Pairwise correlation coefficients of LC50 values showed a positive correlation with cross-resistance among deltamethrin, cypermethrin and chlorpyrifos, while resistance to profenofos showed correlations with resistances to other insecticides except chlorpyrifos. New chemistry insecticides showed no correlations between any of the tested insecticides. There were high to very high levels of resistance to organophosphates in most of the population, which suggested that the use of these should be avoided against this pest. Selective use of pyrethroids in several areas, including Bahawalpur and Lodhran, where the pest showed a low level of resistance, would appear to be acceptable, the new chemistry insecticides, lufenuron, methoxyfenozide, emamectin and indoxacarb had no, very low, low and moderate resistance levels against populations, respectively. These are considered to be safe to the environment and safer to natural enemies. 相似文献
4.
对利用酶抑制分光光度法检测蔬菜上有机磷和氨基甲酸酯类农药残毒的原理、最主要影响因子和存在的问题进行了探讨 ,重点分析了酶抑制分光光度法出现假阳性、负抑制率以及该方法不适用于检测韭菜等蔬菜中的有机磷和氨基甲酸酯类农药残留的原因 相似文献
5.
S.?Stankovi?Email author A.?Zabel M.?Kostic B.?Manojlovic S.?Rajkovic 《Journal of pest science》2004,77(1):11-15
Leptinotarsa decemlineata (Say), the Colorado potato beetle (potato beetle), is the most destructive potato pest in Serbia. Up to four pesticide treatments are necessary for its control. Insecticide resistance of the potato beetle in Serbia is well-investigated and documented, especially to organophosphates and carbamates. Toxicity of chlorpyriphos (organophosphates) and carbosulfan (carbamates) was investigated by topical application, using adults of the first generation from nine field populations. Adults of all populations possessed a certain level of resistance to both insecticides, with very low regression slopes (0.50–1.09 for chlorpyriphos and 0.57–0.85 for carbosulfan). Resistance ratios for chlorpyriphos ranged from 1.0 to 109.7 and from 1.0 to 52.8 for carbosulfan. There was no correlation between resistance to chlorpyriphos and carbosulfan. The key modes of resistance to organophosphates and carbamates are metabolism [overproduction of aliesterase (ALiE), a carboxylesterase] and altering the target site of acetylcholine esterase (AChE). Biochemical research of potato beetle resistance to organophosphates and carbamates, based on activity of ALiE and AChE, proved that the key mode of resistance to organophosphates was modification of ALiE and AChE to carbamates. Our results correspond to this research concerning the lack of correlation between resistances to these two insecticides. A certain level of resistance of the potato beetle to organophosphates and carbamates is widespread in Serbia. Different modes of resistance suggest the possibilities of control of this pest, such as choice of insecticide and insecticide rotation, wherever possible. 相似文献
6.
M.G. Prado-Ochoa P. Ramírez-Noguera R. Díaz-Torres G.I. Garrido-Fariña V.H. Vázquez-Valadez A.M. Velázquez-Sánchez M.A. Muñoz-Guzmán E. Angeles F. Alba-Hurtado 《Veterinary parasitology》2014,199(3-4):215-224
The effects produced by the new synthetic carbamates ethyl-(4-bromophenyl) carbamate and ethyl-(4-chlorophenyl) carbamate on the acetylcholinesterase (AChE) activity, egg structure and reproductive organs of two Rhipicephalus microplus strains were evaluated. Inhibition kinetic parameters showed that the studied carbamates are weak inhibitors and have a low affinity for R. microplus AChE. Histologically, in oocytes from carbamate-treated engorged female ticks, a loss of shape, cytoplasmic vacuoles, decreased chorion deposition, alterations in cytoplasmic granularity and irregular membranes were observed. In oocyte germinal vesicles, a loss of shape, nucleolar fragmentation and membrane alterations with degenerative signs were observed. The ovarian epithelium was vacuolated, flattened, eroded and contained pyknotic nuclei. These alterations were observed from the first day and persisted and increased in severity until day 7 post-treatment. The ovaries from carbamate-treated ticks had fewer stage IV–V oocytes and more stage I–II oocytes. Additionally, eggs produced by the treated ticks had a modified appearance, decreased size, a reduced superficial waxy layer and a loss of viability. The results of this study show that the effects of carbamates on R. microplus were independent of AChE inhibition and show that the morphological alterations in the reproductive organs were due to carbamate actions on the vitellogenesis and viability of the ovarian cells. 相似文献
7.
Robyn J Russell Charles Claudianos Peter M Campbell Tara D Sutherland 《Pesticide biochemistry and physiology》2004,79(3):84-93
Interspecific comparisons of bioassay and biochemical data suggest two major patterns of target site resistance to carbamates and organophosphates. Pattern I resistance, which is generally more effective for carbamates, has been shown in two sub-species of mosquitoes to be due to a particular Gly-Ser mutation in the oxyanion hole within the active site of one of their two acetylcholinesterase enzymes. Intriguingly, different substitutions at the equivalent site confer organophosphate hydrolytic ability on other esterases responsible for metabolic resistance in some other species. In the case of the aphid, Myzus persicae, Pattern I resistance is due to a Ser-Phe mutation in the vicinity of the acyl pocket of acetylcholinesterase. Pattern II resistance is at least as effective for organophosphates as it is for carbamates and may even be specific to organophosphates in some cases. Molecular studies on this pattern of resistance in three higher Diptera show that it is due to changes that constrict the acetylcholinesterase active site gorge and limit binding of the insecticide to the catalytic residues at the base of the gorge. One case of Pattern II resistance in the mosquito, Culex tritaeniorhynchus, involves the same site near the acyl pocket of acetylcholinesterase, albeit a different substitution, as that involved in Pattern I resistance in M. persicae. 相似文献
8.
Dharm Paul Garg Anshoo Malhotra D.K. Dhawan 《Pesticide biochemistry and physiology》2009,93(3):127-132
The present study was planned to evaluate the role of vitamin E, if any, in attenuating the methomyl induced hematological and biochemical alterations in blood of male wistar rats. Animals, in the weight range of 130-150 g, were administered methomyl orally in drinking water at a sub-acute dose level of 4 mg/kg body weight on alternate days for a duration of one month, vitamin E was administered intraperitoneally to normal or methomyl treated rats on alternate days as a pretreatment for a week at a dose level of 50 mg/kg body weight and subsequently for a further period of one month. Methomyl treatment resulted in a significant increase in the levels of lipid peroxidation and super oxide dismutase (SOD) activity in erythrocytes. On the contrary, reduced Glutathione levels (GSH) and the activities of catalase, Glutathione-S-transferase (GST) and Glutathione peroxidase (GSHPx) were found to be significantly decreased. Methomyl treatment caused a significant increase in total leukocyte counts (TLC), platelet, neutrophil, eosinophil, and lymphocyte and monocyte counts. Scanning Electron Micrographs showed significant morphological changes, which included spherocytosis and poikilocytosis. However, vitamin E supplementation to methomyl treated rats significantly decreased the raised levels of LPO whereas it caused a significant increase in GSH levels. Also, vitamin E supplementation could significantly elevate the activities of catalase GSHPx, GST and resulted in the normalization of SOD activity. Vitamin E supplementation also proved to be effective in significantly decreasing the already raised values of TLC and lymphocytes counts and almost normalized the platelets, neutrophils, lymphocytes and monocytes counts. Further, vitamin E supplementation improved the morphology of the red blood cells. The study, therefore, concludes that vitamin E can effectively mitigate most of the adverse effects induced by methomyl in rat blood. 相似文献
9.
对利用酶抑制分光光度法检测蔬菜上有机磷和氨基甲酸酯类农药残毒的原理、最主要影响因子和存在的问题进行了探讨,重点分析了酶抑制分光光度法出现假阳性、负抑制率以及该方法不适用于检测韭菜等蔬菜中的有机磷和氨基甲酸酯类农药残留的原因 相似文献
10.
[目的]建立一种氨基甲酸酯类农药残留分析方法。[方法]对市场上蔬菜随机抽样,采用配荧光检测器和柱后衍生系统的高效液相色谱仪测定了蔬菜中涕灭威砜、涕灭威亚砜、灭多威、3-羟基克百威、涕灭威、克百威、甲萘威7种氨基甲酸酯类农药的多残留,对每种农药进行了3种不同浓度(0.05、0.10、0.50 mg/kg)的添加回收率试验。[结果]蔬菜中7种农药的回收率在74.6%～107.6%,精密度在10%以内。[结论]该方法可用于大白菜、黄瓜、番茄、辣椒、芹菜等样品中氨基甲酸酯类农药残留分析。 相似文献