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1.
Strains of sheep louse Bovicola ovis (Schrank) with various levels of resistance to pyrethroid and one strain with high degree of resistance to organophosphate (OP) insecticides were used to investigate the biochemical mechanisms of insecticide resistance, i.e., enhanced levels of general esterases, specific acetylcholinesterases (AChE), glutathione S-transferase (GST), and mixed function oxidases. Native gel electrophoresis combined with quantitative enzyme assays showed analogous expression profiles of several esterase isozymes in all the strains tested. The determination of the sensitivity of each esterase isozyme to five inhibitors (acetylthiocholine iodide, butyrylthiocholine iodide, paraoxon eserine sulfate, and pCMB) led to the identification of nine esterases in the B. ovis strain. Gel electrophoresis results are supported by enzyme assay studies where, except for the OP resistant strain, no differences in esterase activities were detected in all the pyrethroid resistant and susceptible strains assayed. Statistical analyses demonstrated that some strains have elevated GST activities compared to the susceptible reference strain.  相似文献   

2.

BACKGROUND

Aedes aegypti is a vector of several important human pathogens. Control efforts rely primarily on pyrethroid insecticides for adult mosquito control, especially during disease outbreaks. A. aegypti has developed resistance nearly everywhere it occurs and insecticides are used. An important mechanism of resistance is due to mutations in the voltage‐sensitive sodium channel (Vssc) gene. Two mutations, in particular, S989P + V1016G, commonly occur together in parts of Asia.

RESULTS

We have created a strain (KDR:ROCK) that contains the Vssc mutations S989P + V1016G as the only mechanism of pyrethroid resistance within the genetic background of Rockefeller (ROCK), a susceptible lab strain. We created KDR:ROCK by crossing the pyrethroid‐resistant strain Singapore with ROCK followed by four backcrosses with ROCK and Vssc S989P + V1016G genotype selections. We determined the levels of resistance conferred to 17 structurally diverse pyrethroids, the organochloride DDT, and oxadiazines (VSSC blockers) indoxacarb (proinsecticide) and DCJW (the active metabolite of indoxacarb). Levels of resistance to the pyrethroids were variable, ranging from 21‐ to 107‐fold, but no clear pattern between resistance and chemical structure was observed. Resistance is inherited as an incompletely recessive trait. KDR:ROCK had a > 2000‐fold resistance to DDT, 37.5‐fold cross‐resistance to indoxacarb and 13.4‐fold cross‐resistance to DCJW.

CONCLUSION

Etofenprox (and DDT) should be avoided in areas where Vssc mutations S989P + V1016G exist at high frequencies. We found that pyrethroid structure cannot be used to predict the level of resistance conferred by kdr. These results provide useful information for resistance management and for better understanding pyrethroid interactions with VSSC. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.  相似文献   

3.
昆虫对拟除虫菊酯类杀虫剂的代谢抗性机制研究进展   总被引：1，自引：1，他引：0  
随着拟除虫菊酯类杀虫剂在卫生和农业害虫防治中的广泛应用,昆虫对此类杀虫剂产生抗性的报道越来越多。目前已明确昆虫对拟除虫菊酯类杀虫剂的抗性机制包括表皮穿透率下降、靶标抗性以及代谢抗性,其中代谢抗性机制较为普遍,而且其与昆虫对多种杀虫剂的交互抗性关系密切。目前,随着基因组、转录组以及蛋白质组学等新技术的发展及应用,昆虫对拟除虫菊酯类杀虫剂的代谢抗性机制研究也取得了很多新进展。昆虫体内细胞色素P450酶（P450s）、羧酸酯酶（CarE）及谷胱甘肽S-转移酶（GSTs）等重要解毒酶系的改变均与昆虫对拟除虫菊酯类杀虫剂的代谢抗性有关,其中这3类解毒酶的活性及相关基因表达量的变化是昆虫对此类杀虫剂产生代谢抗性的主要原因。明确昆虫对拟除虫菊酯类杀虫剂的代谢抗性机制,对合理使用此类杀虫剂及延缓抗药性的产生均具有重要意义。本文在总结拟除虫菊酯类杀虫剂代谢路径及相关生物酶研究概况的基础上,综述了近年来有关昆虫对此类杀虫剂代谢抗性机制研究的主要进展。  相似文献   

4.
The susceptibility to pyrethroid, organochlorine, organophosphorus and carbamate insecticides, of 20 strains of houseflies (Musca domestica L.) collected in the Middle East and North Africa, was assessed by topical application. No resistance to pyrethroids was found but most flies were resistant to DDT, gamma-HCH, organophosphorus and carbamate insecticides. Numerical factors of resistance for a susceptible and two different resistant strains, obtained using different bioassay techniques, were compared. High mortality (≥95%) was achieved with ‘resisted’ insecticides in tests with space sprays, but only low, variable mortality resulted from deposit tests. If this occurs under practical field conditions, moderately resistant populations of flies could be controlled by using space sprays containing comparatively high concentrations of active ingredient, but increased levels of deposit would be ineffective.  相似文献   

5.
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   

6.
BACKROUND: In Tetranychus urticae Koch, acetylcholinesterase insensitivity is often involved in organophosphate (OP) and carbamate (CARB) resistance. By combining toxicological, biochemical and molecular data from three reference laboratory and three OP selected strains (OP strains), the AChE1 mutations associated with resistance in T. urticae were characterised. RESULTS: The resistance ratios of the OP strains varied from 9 to 43 for pirimiphos‐methyl, from 78 to 586 for chlorpyrifos, from 8 to 333 for methomyl and from 137 to 4164 for dimethoate. The insecticide concentration needed to inhibit 50% of the AChE1 activity was, in the OP strains, at least 2.7, 55, 58 and 31 times higher for the OP pirimiphos‐methyl, chlorpyrifos oxon, paraoxon and omethoate respectively, and 87 times higher for the CARB carbaryl. By comparing the AChE1 sequence, four amino acid substitutions were detected in the OP strains: (1) F331W (Torpedo numbering) in all the three OP strains; (2) T280A found in the three OP strains but not in all clones; (3) G328A, found in two OP strains; (4) A201S found in only one OP strain. CONCLUSIONS: Four AChE1 mutations were found in resistant strains of T. urticae, and three of them, F331W, G328A and A201S, are possibly involved in resistance to OP and CARB insecticides. Among them, F331W is probably the most important and the most common in T. urticae. It can be easily detected by the diagnostic PCR‐RLFP assay developed in this study. Copyright © 2009 Society of Chemical Industry  相似文献   

7.
BACKGROUND: Glutathione S‐transferases (GSTs) have received considerable attention in insects for their roles in insecticide resistance. Laodelphax striatellus (Fallén) is a serious rice pest. L. striatellus outbreaks occur frequently throughout eastern Asia. A key problem in controlling this pest is its rapid adaptation to numerous insecticides. In this research, nine cDNAs encoding GSTs in L. striatellus were cloned and characterised. RESULTS: The cloned GSTs of L. striatellus belonged to six cytosolic classes and a microsomal subgroup. Exposure to sublethal concentrations of each of the six insecticides, DDT, chlorpyrifos, fipronil, imidacloprid, buprofezin and beta‐cypermethrin, quickly induced (6 h) up‐expression of LsGSTe1. The expression of LsGSTs2 was increased by chlorpyrifos, fipronil and beta‐cypermethrin. Furthermore, exposure of L. striatellus to fipronil, imidacloprid, buprofezin and beta‐cypermethrin increased the expression of the LsGSTm gene after 24 or 48 h. CONCLUSION: This work is the first identification of GST genes from different GST groups in Auchenorrhyncha species and their induction characteristics with insecticide types and time. The elevated expression of GST genes induced by insecticides might be related to the enhanced tolerance of this insect to insecticides and xenobiotics. Copyright © 2012 Society of Chemical Industry  相似文献   

8.
本文采用点滴法和诊断剂量法 ,比较研究了新疆与华北棉区田间种群棉铃虫对不同类型杀虫剂代表品种的抗性差异。结果表明 ,新疆种群对各类药剂均处于敏感水平 ;而华北种群 ,对拟除虫菊酯类杀虫剂已达高抗水平 ,并且kdr型抗性是其重要机制之一 ,同时 ,对有机磷和氨基甲酸酯类杀虫剂也已达中抗水平。  相似文献   

9.
The toxicities of three enzyme inhibitors and their synergistic effects on four insecticides were studied by using the dry film method on field populations of 18 species of insects collected in Jianxin and Shanjie, China, from 2003 to 2005. Meanwhile, the inhibitory effects of these enzyme inhibitors on the activities of acetylcholinesterases (AChE), carboxyesterases (CarE) and glutathione-S-transferases (GST), in vivo, were also studied. In general, triphenyl phosphate (TPP) and diethyl maleate (DEM) showed low toxicities to six herbivorous pest insects, four ladybirds and eight parasitoids. Piperonyl butoxide (PB) exhibited low toxicities to the herbivorous pest insects and ladybirds, but high toxicities to the eight parasitoids. The tolerance to the insecticides in 11 pest insects and natural enemies was mainly associated with the tolerance to PB. PB showed the highest synergism on methamidophos, fenvalerate, fipronil and avermectin in nine species of pest insects and natural enemies. In general, TPP and DEM showed significant synergisms to these four insecticides in four parasitoid species. However, in contrast to their effects on the parasitoids, the synergistic effects of TPP and DEM on the four insecticides by TPP and DEM against four pest insects and one ladybird varied depending on the insect species and enzyme inhibitor. Activity of AChE, CarE or GST could be strongly inhibited, in vivo, by PB, TPP or DEM, depending on the insect species and enzyme inhibitors. From the results obtained in this study, mixed-function oxidase (MFO) was thought to play the most critical role in insect tolerances to the tested insecticides in the field. Low competition existed in the evolution of insecticide resistance in the field populations of parasitoids, as compared with herbivorous pest insects and ladybirds. Possible causes of the high synergistic effects of PB on the four classes of insecticides, based on multiattack on the activity of CarE, GST or AChE in the insect species, are also discussed.  相似文献   

10.
BACKGROUND: Trialeurodes vaporariorum Westwood is an important pest of protected crops in temperate regions of the world. Resistance to pyrethroid insecticides is long established in this species, but the molecular basis of the mechanism(s) responsible has not previously been disclosed. RESULTS: Mortality rates of three European strains of T. vaporariorum to the pyrethroid bifenthrin were calculated, and each possessed significant resistance (up to 662‐fold) when compared with a susceptible reference strain. Direct sequencing revealed three amino acid substitutions in the para‐type voltage‐gated sodium channel (the pyrethroid and DDT target site) of bifenthrin‐resistant T. vaporariorum at positions previously implicated with pyrethroid or DDT resistance (M918L, L925I and T929I) in other related species. CONCLUSION: This study indicates that resistance to bifenthrin in T. vaporariorum is associated with target‐site insensitivity, and that the specific mutations in the sodium channel causing resistance may differ between localities. Copyright © 2012 Society of Chemical Industry  相似文献   

11.
The development of resistance in the Oriental fruit moth, Grapholita molesta (Busck) to organophosphorus (OP) insecticides (azinphos-methyl and phosmet) is a serious threat to the tender fruit industry in Ontario (50% crop losses in 1994). Resistance to carbamate insecticides and increased survival of field-collected moths at diagnostic concentrations of pyrethroids were widespread. As a result, four different treatment regimes were tested to manage resistance in G molesta, and the changes in resistance frequencies under each treatment regime were monitored from 1996 to 1999. The data indicated that the levels of resistance were significantly influenced by the various treatment regimes. The seasonal pattern of resistance was similar for all treatment regimes, in that resistance peaked in mid-season and declined in the late season. Levels of resistance in G molesta to OPs decreased from 55% to 14% and that to pyrethroids declined from 30% to 10% from 1996 to 1999 under a treatment regime consisting of endosulfan-organophosphate-pyrethroid rotation. Similarly, under a treatment regime implemented in commercial orchards (organophosphate-pyrethroid rotation), resistance to OP insecticides declined from 50% to 12% and resistance to pyrethroids evolved to around 16%. The overall data indicated that resistance was unstable; a strategy based on rotation of insecticides by class for each generation of G molesta was successful in managing resistance to both OP and pyrethroid insecticides. The rotational strategy has been widely adopted by growers and is applied to ca 85% of the acreage.  相似文献   

12.
The toxicity of topically applied DDT to adult female anautogenous mosquitoes (Culex pipiens L.) showed dramatic variations in blood-fed insects. It decreased very rapidly about twofold to a minimum at 24 hr after a blood meal, then increased within 72 hr back to values typical of non-blood fed insects. A comparison of the metabolism of [14C]DDT in vivo revealed an increase in DDT dehydrochlorination to DDE at 72 hr after a blood meal, but this increase was not responsible for the variations in DDT toxicity at 24 hr. Changes in penetration rates were not observed and changes in the distribution of DDT could likewise not be related to the short period of decreased toxicity of DDT. Fenvalerate and trans-permethrin, two pyrethroid insecticides which are believed to have a mode of action similar to that of DDT, were also significantly less toxic 24 hr after a blood meal. By contrast, the cyclodiene insecticide aldrin and the carbamate insecticide propoxur were not less toxic 24 hr after a blood meal. The results suggest that after a blood meal an unidentified and transient change in C. pipiens specifically decreases DDT/pyrethroid toxicity. A hypothesis concerning this transient change is advanced. The results illustrate the difficulties in explaining physiological changes in insecticide toxicity.  相似文献   

13.
Synergists were used to diagnose possible mechanisms of permethrin resistance in permethrin-selected strains of the tobacco budworm, Heliothis virescens (F.). In addition to permethrin, these strains of the tobacco budworm were resistant to α-cyano-pyrethroid insecticides, organophosphorus insecticides and DDT. The monooxygenase-inhibiting prop-2-ynyl aryl ethers were the only effective synergists of permethrin among 16 candidates tested. The most effective synergist was 1,2,4-trichloro-3-(2-propynyloxy)benzene. Piperonyl butoxide, a common monooxygenase-inhibiting synergist in other species and tobacco budworm strains, was inactive. These results suggested the presence and contribution of an unusual monooxygenase in the enzymatic detoxication of permethrin. DDT cross-resistance, which was not synergized, and broad pyrethroid cross-resistance supported previous evidence for target site insensitivity as a second pyrethroid-resistance mechanism in these strains. The actions of S,S,S-tributyl phosphorotrithioate (TBPT) and triphenyl phosphate (TPP) suggested that hydrolytic detoxication, important in methyl parathion-resistance tobacco budworm strains, had little or no role in conferring pyrethroid resistance in these strains.  相似文献   

14.
Pyrethroids, knockdown resistance and sodium channels   总被引：1，自引：0，他引：1  
Knockdown resistance to DDT and the pyrethrins was first described in 1951 in the housefly (Musca domestica L.). This trait, which confers reduced neuronal sensitivity to these insecticides, was subsequently shown to confer cross-resistance to all synthetic pyrethroid insecticides that have been examined to date. As a consequence, the worldwide commercial development of pyrethroids as a major insecticide class over the past three decades has required constant awareness that pyrethroid overuse has the potential to reselect this powerful resistance mechanism in populations that previously were resistant to DDT. Demonstration of tight genetic linkage between knockdown resistance and the housefly gene encoding voltage-sensitive sodium channels spurred efforts to identify gene mutations associated with knockdown resistance and understand how these mutations confer a reduction in the sensitivity of the pyrethroid target site. This paper summarizes progress in understanding pyrethroid resistance at the molecular level, with particular emphasis on studies in the housefly.  相似文献   

15.
草地贪夜蛾Spodoptera frugiperda是一种迁飞性害虫,源自美洲,已入侵非洲和亚洲部分国家并暴发成灾,2019年初入侵我国,严重威胁着我国玉米、小麦等粮食作物。目前草地贪夜蛾的防治主要依赖于化学农药和种植转基因作物。因长期使用农药,草地贪夜蛾已经对氨基甲酸酯类、有机磷酸酯类和拟除虫菊酯类等多种杀虫剂产生了不同程度的抗性。草地贪夜蛾对不同种类杀虫剂表现的抗性机制不同,主要有代谢抗性和靶标抗性2种。本文主要从代谢抗性和靶标抗性2个方面分别综述了草地贪夜蛾对不同种类杀虫剂的抗性机制,分析草地贪夜蛾对不同杀虫剂的抗性作用方式,并对草地贪夜蛾抗药性管理和监测进行展望。  相似文献   

16.
Samples of housefly (Musca domestica) field populations were collected from Danish livestock farms in 1997. The tolerance of the first‐generation offspring was determined for a number of insecticides. Dose‐response values were obtained by topical application for the pyrethroids bioresmethrin and pyrethrum, both synergised with piperonyl butoxide, and the organophosphate dimethoate. The organophosphates azamethiphos and propetamphos and the carbamate methomyl were tested in discriminating dose feeding bioassays. Resistance was low to moderate in most of the populations for most of the compounds tested, but this study also revealed the existence of high resistance to pyrethroid, organophosphate and carbamate insecticides in some populations. The resistance factors at LD50 for bioresmethrin/piperonyl butoxide ranged between 2 and 98, and for pyrethrum/piperonyl butoxide between 2 and 29. Our results indicate that pyrethroid resistance in Denmark is increasing, since four of the 21 farms showed more than 100‐fold resistance at LD95, a level of resistance only observed once before. Resistance factors at LD50 for dimethoate ranged from 9 to 100, and showed two distinct trends: populations with either decreasing or increasing resistance. Resistance to azamethiphos was found to be widespread and high. Although two strains with high methomyl and propetamphos resistance were observed, methomyl and propetamphos resistance is moderate and appears not to be increasing. © 2001 Society of Chemical Industry  相似文献   

17.
BACKGROUND: The accuracy of predicting the survival of insecticide‐resistant aphids following the application of commonly used insecticides from the carbamate, the pyrethroid, a mix of the two or the neonicotinoid chemical classes was evaluated in a potato field in Scotland. Equal proportions of five genotypes of the peach‐potato aphid, Myzus persicae (Sulzer), with none, resistance to dimethyl‐carbamates, resistance to pyrethroids or combinations conferring resistance to both chemical classes were released into potato field plots. The insecticides were sprayed separately onto these plots, the aphid populations were analysed after 6–8 days and the process repeated. RESULTS: For each assessment after the three separate spray events, plots treated with the carbamate had 48, 147 and 28%, those treated with pyrethroid 53, 210 and 89%, those treated with carbamate/pyrethroid 28, 108 and 64% and those treated with neonicotinoid 43, 55 and 11% of the numbers of M. persicae by comparison with untreated controls. Only the proportions of surviving aphids from the genotype containing no insecticide resistance traits and the genotype containing elevated carboxylesterases matched ratios predicted from the selective advantage afforded by the resistance traits alone. Survival of aphids from the other three genotypes that carried 1–3 of the insecticide resistance traits differed from expectations in all cases, possibly owing to physiological differences, including their vulnerability to predators and hymenopterous parasitoids present at the site and/or their carrying unknown insecticide resistance mechanisms. CONCLUSION: Control strategies based on knowledge of the genetically determined insecticide resistance profile of an M. persicae population alone are insufficient. Hence, other important factors contributing to aphid survival under insecticide pressure need to be considered. Copyright © 2012 Society of Chemical Industry  相似文献   

18.
Pyrethroid resistance in B-type Bemisia tabaci Gennadius and Australian Helicoverpa armigera Hübner field populations is primarily conferred by esterase isoenzymes which metabolise and sequester pyrethroid insecticides. It has been shown previously that pyrethroid resistance-associated esterases in H. armigera are inhibited by the insecticide synergist piperonyl butoxide (PBO) over a 22-h period. It is demonstrated here that similar inhibition can be obtained against B-type B. tabaci. Small-scale field trials showed excellent levels of pyrethroid control when insects were pretreated with PBO and then dosed with pyrethroid during the time of maximum esterase inhibition. These results demonstrate that PBO can restore pyrethroid efficacy in the field against both B-type B. tabaci and resistant H. armigera.  相似文献   

19.
为明确黑龙江省西部草原蝗虫对杀虫剂的抗性,实现对草原蝗虫的高效节药治理,采用点滴法于2010年和2013年检测当地优势种大垫尖翅蝗Epacromius coerulipes不同种群对10种常规杀虫剂的敏感性,并测定3种增效剂对杀虫剂的增效作用.结果 显示,与相对敏感基线相比,2010年大垫尖翅蝗肇源、林甸和杜蒙种群对有...  相似文献   

20.
The prolonged use of dimethoate, introduced into Denmark to control houseflies (Musca domestica L.) that had become resistant to parathion and diazinon, resulted ultimately in dimethoate resistance. Selection with dimethoate led to the disappearance of the hydrolytic phosphatase, a major mechanism of resistance to parathion and diazinon, and its replacement by the acetylcholinesterase AChER with somewhat decreased sensitivity to inhibition by organophosphorus (OP) insecticides. The hydrolytic phosphatase probably disappeared because low substrate turn-over made it ineffective against dimethoxon (O, O-dimethyl S-methylcarbamoylmethyl phosphorothioate, also known as omethoate). which accumulates at higher concentrations than paraoxon (diethyl4-nitrophenyl phosphate) in the haemolymph. Dimethoate selected AChER preferentially because it improved the chances of houseflies surviving against the relatively poor AChE inhibitor dimethoxon, whereas its relatively small insensitivity to OP insecticides, unimportant against good inhibitors such as paraoxon, prevented its selection by parathion.  相似文献   

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