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1.
Anticholinesterase activity in vitro of pure fenitrothion, S-methyl fenitrothion (SMF) and mixtures of both was studied using different sources of cholinesterase. SMF was two to three orders as active an inhibitor as fenitrothion. In the mixtures, 1 and 5% SMF significantly influenced the I50 value of fenitrothion. The hydrolysis rates of both compounds are given. A method for the synthesis of pure SMF is also described.  相似文献   

2.
BACKGROUND: Five formulated insecticides (lambda‐cyhalothrin at 10 mg m?2, bifenthrin at 50 mg m?2, fipronil at 10 mg m?2, fenitrothion at 50 mg m?2, imidacloprid at 5 mg m?2) and one active ingredient (DDT at 500 mg m?2) were evaluated using a surface contact method against early and late instars and adults of two strains of the tropical bed bug, Cimex hemipterus (F.). Synergism of lambda‐cyhalothrin and fipronil using piperonyl butoxide (PBO) was also assessed. RESULTS: The order of susceptibility of different stages of bed bugs was as follows: early stage ? lambda‐cyhalothrin > bifenthrin = imidacloprid > fipronil > fenitrothion > DDT; late stage—lambda‐cyhalothrin > bifenthrin > fenitrothion > imidacloprid > fipronil > DDT; adult—lambda‐cyhalothrin > imidacloprid > bifenthrin > fenitrothion > fipronil > DDT. The late instars exhibited significantly higher LT50 among the life stages. The addition of PBO to fipronil increased the susceptibility of the insects. CONCLUSIONS: Lambda‐cyhalothrin, bifenthrin, fenitrothion and fipronil at the recommended application rates were effective against C. hemipterus. Although imidacloprid demonstrated good initial response against C. hemipterus, the insects showed substantial recovery 72 h post‐treatment. The late instars (fourth and fifth instars) should be used as the model for toxicological evaluation. Copyright © 2011 Society of Chemical Industry  相似文献   

3.
Formic, acetic, or n-propionic acid applied with fenitrothion to Tribolium castaneum, inhibited the production of both fenitroxon and O-desmethyl fenitrothion, but did not appear to affect metabolic attack on the P-O-phenyl link. These effects are comparable to those of some pyrethrum synergists. The toxicity of fenitrothion was synergised by formic or acetic acid, and antagonised by propionic acid, but these effects on potency were slight.  相似文献   

4.
Gas and liquid chromatographic methods were evaluated for determining the impurities in technical grade fenitrothion (≥95%). These impurities were S-methyl fenitrothion. fenitrooxon, bis-fenitrothion, S-methyl-bis-fenitrothion and 3-methyl-4-nitrophenol. The GC proved to be insensitive to the two bis compounds whereas these compounds could be analysed by liquid chromatography on a Corasil 11 column or on an OPN column. Nine technical samples were analysed and S-methyl fenitrothion, a potent anticholinesterase agent, was by far the most common impurity.  相似文献   

5.
Bioassays were conducted in stored grains to evaluate the combined use of the entomopathogenic fungus Beauveria bassiana, diatomaceous earth (DE) and fenitrothion against adults of Rhyzopertha dominica and Tribolium castaneum. The insecticide agents were applied to wheat as follows: the fungus at 1 × 108 conidia/kg of wheat, DE at 3 g/kg of wheat and fenitrothion at a rate of 0.15 ml/kg of wheat (25% of field dose rate). Surviving insects and progeny production were monitored at thirty-day intervals until four months. For both insect species, significantly less progeny was produced on wheat treated with fenitrothion and DE + B. bassiana formulations in comparison with controls. The effect of insecticides on the grain damage, germination power of wheat and bulk density was also evaluated. After four months, B. bassiana mixed with DE reduced the damaged insect grains by 50% in comparison with both fenitrothion and control treatments. Trials using DE caused a reduction in bulk density while there were no significant differences for germination testing between treatments.  相似文献   

6.
1983—1986年通过室内毒力测定比较,在20种供试农药中筛选出杀螟松对麦蚜具有很高毒力,田间试验和示范表明,小麦不同部位农药沉积量同药效呈正相关,杀螟松对小麦各部位的蚜虫均有良好防效。1985—1986年在京、冀、甘、川、豫等省示范和推广10多万亩,每亩用50％乳油30毫升,无论用高容量、低容量、超低容量或吹雾法喷雾,防效均在90％以上。杀螟松是我国正在发展的大吨位农药品种,具有防效好、药源广、成本低、对人畜安全、无残毒等优点。作者认为是值得推荐的防治麦蚜的农药品种。  相似文献   

7.
BACKGROUND: To evaluate the insecticide susceptibility status of Aedes aegypti (L.) in Colombia, and as part of the National Network of Insecticide Resistance Surveillance, 12 mosquito populations were assessed for resistance to pyrethroids, organophosphates and DDT. Bioassays were performed using WHO and CDC methodologies. The underlying resistance mechanisms were investigated through biochemical assays and RT‐PCR. RESULTS: All mosquito populations were susceptible to malathion, deltamethrin and cyfluthrin, and highly resistant to DDT and etofenprox. Resistance to lambda‐cyhalothrin, permethrin and fenitrothion ranged from moderate to high in some populations from Chocó and Putumayo states. In Antioquia state, the Santa Fe population was resistant to fenitrothion. Biochemical assays showed high levels of both cytochrome P450 monooxygenases (CYP) and non‐specific esterases (NSE) in some of the fenitrothion‐ and pyrethroid‐resistant populations. All populations showed high levels of glutathione‐S‐transferase (GST) activity. GSTe2 gene was found overexpressed in DDT‐resistant populations compared with Rockefeller susceptible strain. CONCLUSIONS: Differences in insecticide resistance status were observed between insecticides and localities. Although the biochemical assay results suggest that CYP and NSE could play an important role in the pyrethroid and fenitrothion resistance detected, other mechanisms remain to be investigated, including knockdown resistance. Resistance to DDT was high in all populations, and GST activity is probably the main enzymatic mechanism associated with this resistance. The results of this study provide baseline data on insecticide resistance in Colombian A. aegypti populations, and will allow comparison of changes in susceptibility status in this vector over time. Copyright © 2011 Society of Chemical Industry  相似文献   

8.
Insecticide assays using larvae of Cryptophlebia leucotreta Meyrick (Lepidoptera: Tortricidae; subfamily Olethreutinae) showed that parathion-methyl and monocrotophos were more toxic than fenitrothion and endosulfan. The LD90 were 3.44 mg/kg and 11.0 mg/kg for parathion-methyl and monocrotophos, respectively. The order of relative efficiency of the insecticides was as follows: parathion-methyl, monocrotophos, fenitrothion and lastly endosulfan. When different spray machines were tested for spray deposition on well grown cotton plants, the motorised airblast sprayer effected a more satisfactory deposit recovery on the lower parts of the cotton plants where early and heavy infestation of C. leucotreta to the mature cotton bolls occurs.  相似文献   

9.
Abstract

Field trials were conducted against the major pests of jute from 1972–74. Endrin, endosulfan, phosalone, fenitrothion, carbaryl + molasses and fenitrothion + malathion were applied five times at 15 day intervals against Apion corchori, Anomis sabulifera and Polyphagotarsonemus latus. Three years data was pooled and analysed statistically. Endosulfan 0.075% a.i. proved superior to all other treatments.  相似文献   

10.
Organophosphothionate insecticide fenitrothion is known as potential toxic pollutant contaminating aquatic ecosystems. The effects of fenitrothion were studied to determine the 96 h LC50 value on Nile tilapia (Oreochromis niloticus) and investigate histopathological responses of fish exposed to sublethal fenitrothion concentrations. Data obtained from the fenitrothion acute toxicity tests were evaluated using the Probit Analysis Statistical Method. The 96 h LC50 value and 95% confidence limit for Nile tilapia (58.70 ± 6.97 g) was estimated as 0.84 (0.68-1.15) mg/L. Behavioral changes were observed closely during the acute toxicity test. The bioassay experiments were repeated three times and static test method was used. Some fish exposed to 96 h 0.1, 0.5 mg/L fenitrothion concentrations showed histopathological alterations in the gills, liver, kidney, brain and testes. Severely deformations were observed at 0.5 mg/L fenitrothion on the gills lamella such as hyperemia, epithelial hyperplasia, fusion and telangiectasis, in the liver tissue such as cloudy swelling, hydropic degenerations and lipid infiltration. In addition hyperemia and hemorrhage observed in kidney tissue and hyperemia was determined in brain tissue.  相似文献   

11.
The toxicity of the S-methyl isomer of fenitrothion was found to be higher than that of both fenitrothion and technical fenitrothion. Repeated administration of the compound showed a rapid decrease in toxicity with decreasing doses.Excretion of p-nitro-m-cresol into the urine of rats was more rapid and the excreted amounts were larger from a single dose of the isomer than from fenitrothion.Single doses of the isomer increased the pentobarbitone sleeping time in mice at both 24 and 48 hr, but showed no change after 4 days. Administration of the isomer and purified fenitrothion to mice for 1 week had no effect on the pentobarbitone sleeping time, nor did a single dose of fenitrothion change the effectiveness of pentobarbitone.Dominant lethal tests in rats revealed a possible mutagenic effect from this compound.The anticholinesterase activity of the fenitrothion S-methyl isomer in vitro was found to be two to three times higher than that of fenitrothion.  相似文献   

12.
Effects of three insecticides, diazinon, fenitrothion and chlorpyrifos on Andrallus spinidens Fabricius (Hemiptera: Pentatomidae), a predator of lepidopterous larvae in rice fields were investigated. The insecticides were applied topically at lethal dose (LD30) on the fifth instar nymphs of A. spinidens and evaluated on life table and some biochemical parameters of the predatory bugs. The results showed that pre-oviposition period, fecundity and longevity of treated bugs were significantly affected compared with the control. Analysis of life table parameters of A. spinidens revealed adverse effects of insecticides on net reproductive rate (R0), intrinsic rate of increase (r), finite rate of increase (λ), doubling time (DT) and mean generation time (T). Among the tested insecticides, fenitrothion was the most toxic insecticide. The lowest value of r was 0.060 day?1 in fenitrothion. Effects of insecticides on the detoxification enzymes showed that all compounds had inhibitory effect on esterases, acetylcholinesterases and glutathione S-transferases. According to this study, the insecticides cause harmful effects on demographic and biochemical parameters of A. spinidens and are not compatible with the predatory bug even at sublethal concentration.  相似文献   

13.
The butyl ester of buthionine sulfoximine (BBSO) applied topically to the nymph V stage of Triatoma infestans (Klug) caused glutathione depletion which was maintained for four days after treatment. Topical pre-treatment of nymph V with BBSO significantly synergised the toxicity of DDT and fenitrothion to T. infestans.  相似文献   

14.
Quercetin and thymol blue were shown to synergize the toxicity of fenitrothion to Triatoma infestans with synergistic ratios of 1.89 and 2.65 respectively. These synergistic ratios were statistically significant at P<0.05. Both compounds inhibited glutathione S-transferases (GST) in vitro, with pI50 values of 6.1 and 5.1 respectively. Quercetin or thymol blue caused in-vivo GST inhibition without affecting non-specific esterase (NSE) or acetylcholinesterase (AChE) activity. Incubation of [14C]fenitrothion with T. infestans or rabbit liver GST produced desmethylfenitrothion as the major metabolite, which was specifically diminished in the presence of 0.3 mM quercetin. [14C]Fenitrothion toxicokinetics study showed a significant decrease (P<0.05) in radioactivity due to polar metabolites when insects were pre-treated with quercetin. These facts suggest that both assayed chemicals may be active in synergizing fenitrothion toxicity due to their ability to prevent the detoxification of organophosphorus insecticides by GSH conjugation. © 1999 Society of Chemical Industry  相似文献   

15.
To estimate the impact of fenitrothion on small mammals, a breeding colony of wild southern red-backed voles (Clethrionomys gapperi) was successfully maintained. The red-backed vole is a nontarget species inhabiting coniferous forests that are subjected to aerial spraying of the pesticide for the control of spruce budworm infestations. The voles were used to examine toxicity and the metabolic pathways involved in the elimination of fenitrothion after intraperitoneal injection of the purified, undiluted organophosphate. The 96-hr LD50 was 1330 mg/kg. Toxicities toward males and females were not significantly different. All observed symptoms of intoxication and 99% of the mortality occurred within 48 hr of dose application. All major metabolites of fenitrothion metabolism in nonruminant mammals were identified and quantified by gas chromatography. At all doses, fenitrothion was rapidly metabolized and excreted. No body accumulation of residues was implied. The toxicity of fenitrothion was not correlated with increasing proportion of the dose converted into fenitrooxon. The low toxicity to red-backed voles is probably due, in part, to rapid metabolic detoxication by the two mechanisms cleaving fenitrothion at the P-O-aryl and PO-alkyl bonds, the latter becoming more prominent at high dose levels.  相似文献   

16.
灭多威与杀虫剂的联合毒力研究   总被引：1，自引：0，他引：1  
室内采用浸渍法、喷雾法和点滴法分别进行了灭多威与杀螟硫磷、灭多威与异丙威对蚜虫和粘虫的联合毒力测定。结果表明灭多威与杀螟硫磷以１：７比例混配对蚜虫和粘虫均表现为增效作用,共毒系数（ＣＴＣ）分别为２４９．０３和１８０．３０;灭多威与异丙威以１：２比例混配对蚜虫和粘虫表现为显著增效,共毒系数分别为２３５．４５和２７４．３０。比较了３种生测方法对灭多威的杀虫活性影响  相似文献   

17.
Duplicate field trials were carried out on bulk wheat in commercial silos in Queensland and New South Wales. Laboratory bioassays on samples of treated grain at intervals over 9 months, using malathion-resistant strains of insects, established that treatments were generally effective. Fenitrothion (12 mg kg?1)+ (1R)-phenothrin (2 mg kg?1) was more effective than pirimiphos-methyl (6 mg kg?1) + carbaryl (10 mg kg?1) against Sitophilus oryzae (L.) and Ephestia cautella (Walker); the order of effectiveness was reversed for S. granarius (L.). Against Rhyzopertha dominica (F.), Tribolium castaneum (Herbst), T. confusum Jackquelin du Val and Oryzaephilus surinamensis (L.), both treatments effectively prevented the production of progeny. The order of persistence was pirimiphos-methyl> (1R)-phenothrin>carbaryl or fenitrothion. During processing from wheat to white bread, residues were reduced by 98% for carbaryl, >44% for (1R)-phenothrin, 98% for fenitrothion and 85% for pirimiphosmethyl.  相似文献   

18.
Field trial studies have been performed with captan and fenitrothion on cauliflower to propose maximum residue limits and to study the dissipation of the pesticides. Residue levels have been determined at different times following good laboratory practice using gas chromatography with mass spectrometric detection. The behaviour of residue levels of these compounds after household processing has been analysed using gas chromatography with electron capture detection. Seven days after treatment, residue levels of captan could be detected, but not of fenitrothion. The half-lives of dissipation for captan and fenitrothion were calculated as 0.9 and 1.8 days respectively. Washing did not significantly affect the residual amounts of captan and fenitrothion observed in raw vegetables; however, after cooking, captan had degraded completely, whereas residue levels of fenitrothion were not modified significantly.  相似文献   

19.
The metabolism of fenitrothion was investigated in highly resistant (Akita-f) and susceptible (SRS) strains of the house fly, Musca domestica L. The Akita-f strain was 3500 times more resistant to fenitrothion than the SRS strain. Fenitrothion, topically applied to the flies, was metabolized in vivo far faster in the Akita-f strain than in the SRS strain. In vitro studies revealed that fenitrothion was metabolized by a cytochrome P-450-dependent monooxygenase system and glutathione S-transferases. The former oxidase system metabolized fenitrothion in vitro into fenitrooxon and 3-methyl-4-nitrophenol as major metabolites, and into 3-hydroxymethyl-fenitrothion and 3-hydroxymethyl-fenitrooxon as minor metabolites. Glutathione S-transferases metabolized fenitrothion into desmethylfenitrothion. The cytochrome P-450-dependent monooxygenase system and glutathione S-transferases of the resistant Akita-f strain had 1.4 to 2.2 times and 9.7 times, respectively, as great activities as those of the susceptible SRS strain. These results suggest the importance of glutathione S-transferases in fenitrothion resistance in the Akita-f strain.  相似文献   

20.
Trials were carried out over two consecutive years to compare the efficacy of chlorpyrifos-methyl, etrimfos, fenitrothion and pirimiphos-methyl against susceptible and organophosphorus-resistant strains of Tribolium castaneum Herbst, Sitophilus granarius L. and Oryzaephilus surinamensis L., gamma-HCH-resistant strains of Acarus siro L. and Glycyphagus destructor Schrank, and a susceptible strain of Tyrophagus longior Ger-vais. Pirimiphos-methyl was not evaluated against the three mite species as data on the efficacy of this material had previously been published. Etrimfos and pirimiphos-methyl were also tested against a susceptible and an organophosphorus-resistant strain of Sitophilus oryzae L. Each pesticide was applied to two separate 20-tonne batches of English wheat and stored under ambient conditions for 36 weeks. The efficacy of the pesticides was assessed regularly over the storage period using established bioassay techniques. However, chlorpyrifos-methyl and fenitrothion were assessed against susceptible and resistant strains of S. granarius for 32 weeks only. Each of the four pesticides produced >95% mortality of the susceptible strain of all insect species tested for the entire duration of the trial with the exception of fenitrothion, when survival of T. castaneum increased after 32 weeks. Only fenitrothion failed to give 100% mortality of the resistant strain of S. granarius throughout the trial, but even so, the mortality was always >95%. Chlorpyrifos-methyl, etrimfos and pirimiphos-methyl gave much better control of the resistant T. castaneum than fenitrothion, and etrimfos gave slightly better control of resistant O. surinamensis than pirimiphos-methyl which was in turn better than chlorpyrifos-methyl at 36 weeks. Both etrimfos and pirimiphos-methyl gave 100% mortality of the susceptible and resistant strains of S. oryzae. None of the pesticides maintained 100% kill of A. siro throughout the trial and fenitrothion failed to achieve this level of mortality after only 4 weeks. Etrimfos produced 100% mortality of the other two mites species tested throughout the trial, whereas both chlorpyrifos-methyl and fenitrothion achieved this level of mortality for 32 weeks.  相似文献   

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