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1.
BACKGROUND: Pollen beetle (Meligethes spp.) is a major pest of European oilseed rape crops. Its resistance to pyrethroid insecticides has been recorded in samples of beetles collected in Europe since at least 1999, and problems with the control of the beetle in the field have been widely reported. In 2007, a Pollen Beetle Working Group was formed through the Insecticide Resistance Action Committee (IRAC) in order to coordinate efforts for surveying pyrethroid resistance development. RESULTS: The results of the first 3 years of the pollen beetle pyrethroid susceptibility survey using a laboratory test are presented in this paper. Resistant beetle samples were collected from 20 of the 21 countries surveyed, with a general trend of increasing frequency and spread of resistant samples in European oilseed‐rape‐growing regions. CONCLUSION: Pyrethroid‐resistant beetles dominate in Western and Central Europe and are becoming established in the North and East, the main oilseed‐rape‐growing areas of Europe. The development and spread of pyrethroid‐resistant pollen beetles highlights the need for effective management strategies for oilseed rape insect pests. Copyright © 2011 Society of Chemical Industry  相似文献   

2.
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   

3.
Laboratory bioassays were carried out to determine the toxicity to Folsomia candida Willem (Collembola: Isotomidae) of residues of a pyrethroid insecticide, deltamethrin, and an organophosphorus insecticide, dimethoate, on different leaf surfaces. The test leaves included a range of species and leaves of different ages. Dose-response relationships were estimated for F candida walking over the various treated leaf substrates. Probit analysis was used to estimate the means and standard deviations of the associated tolerance distributions expressed as gAIha-1. Parallelism tests were undertaken to compare the susceptibilities of F candida to the two compounds applied to the different leaf surfaces. On deltamethrin-treated leaf surfaces, the LD50 values for F candida varied from 6.36 to 77.14 gAIha-1. F candida was least susceptible to deltamethrin residues when applied to leaves of dwarf bean (Phaseolus vulgarus L) and the highest susceptibility was observed following application to leaves of seedlings of barley (Hordeum vulgare L). In contrast, the LD50 values observed for dimethoate treatments did not differ significantly between leaf types, ranging from 1.35 to 8.69 gAIha-1. The laboratory data on susceptibility of F candida on different leaf types for different pesticides can be used to investigate the role of leaf surface properties in modifying the toxicity of applied pesticides to exposed invertebrates.  相似文献   

4.
At a time of increasing demand for rapeseed oil for biofuel and food use and as increasing areas are grown, the risk of pollen beetle resistance to pyrethroids presents a significant threat to the sustainability of the oilseed rape crop and to farm incomes. Measures are urgently required to reduce the use of insecticides against pollen beetles, to preserve activity of the limited armoury of insecticides and minimise environmental pollution. In this paper, the status of pollen beetle resistance to pyrethroid insecticides and current control methods are presented from a UK perspective. Three ecological approaches to the control of pollen beetles that are based on research into their behaviour and ecology and that of their natural enemies are highlighted: use of monitoring, trap cropping and conservation biological control. These approaches have the potential to significantly reduce insecticide use against pollen beetles by helping to identify when spray thresholds have been breached, reducing pest incidence in the crop and increasing populations of natural enemies, respectively.  相似文献   

5.
The major mechanism of resistance to most insecticides in Frankliniella occidentalis (Pergande) is metabolic, piperonyl butoxide (PBO) suppressible, mediated by cytochrome-P450 monooxygenases and conferring cross-resistance among insecticide classes. The efficacy of insecticide mixtures of acrinathrin, methiocarb, formetanate and chlorpyrifos was studied by topical exposure in strains of F. occidentalis selected for resistance to each insecticide. The method consisted in combining increasing concentrations of one insecticide with a constant low rate of the second one as synergist. Acrinathrin activity against F. occidentalis was enhanced by carbamate insecticides, methiocarb being a much better synergist than formetanate. Monooxygenase action on the carbamates would prevent degradation of the pyrethroid, hence providing a level of synergism by competitive substrate inhibition. However, the number of insecticides registered for control of F. occidentalis is very limited, and they are needed for antiresistance strategies such as mosaics and rotations. Therefore, a study was made of the synergist effect of other carbamates not used against thrips, such as carbofuran and carbosulfan, against a susceptible strain and a field strain. Neither carbamate showed synergism to acrinathrin in the susceptible strain, but both did in the field strain, carbosulfan being a better synergist than carbofuran. The data obtained indicate that low rates of carbamates could be used as synergists to restore some pyrethroid susceptibility in F. occidentalis.  相似文献   

6.
BACKGROUND: Because bedbugs, Cimex lectularius L., have not been a problem in the USA for over 40 years, few insecticide products are labeled for their control. Most products that are labeled for bedbugs are pyrethroids. However, recent studies indicate that field‐collected bedbugs may be resistant to pyrethroids. There are also non‐pyrethroid products labeled for bedbugs, but, like the pyrethroids, none of these products has been evaluated for field efficacy. This study evaluated the efficacy of two insecticide treatment regimens for bedbugs in multi‐unit housing. Both of the treatments included multiple products currently being used by the pest management industry. RESULTS: The ‘traditional’ treatment consisted of applications of pyrethroid products and an insect growth regulator. The ‘novel’ treatment consisted of applications of non‐pyrethroid products. The traditional treatment significantly reduced the number of bedbugs from 39.8 ± 10.1 per unit prior to treatment to 2.2 ± 1.0 at the end of the test period (P = 0.02; 95% reduction). The number of live bedbugs in the ‘novel’ treatment was also significantly reduced from 71.4 ± 25.3 bedbugs per unit to 10.2 ± 4.4 after 8 weeks (86% population reduction). CONCLUSIONS: Although both treatment regimens reduced bedbug numbers, the fact that bedbugs were not eliminated after multiple applications suggests that the insecticides, applied at the current label rates, were inadequate. These results suggest that a more integrated approach to bedbug control is necessary in multi‐unit housing situations. Copyright © 2008 Society of Chemical Industry  相似文献   

7.
The pollen beetle Meligethes aeneus F. is the most important pest of rapeseed [ Brassica rapa subsp. oleifera (DC.) Metzg.] in Finland. After over 20 years of intensive rapeseed growing and annual spraying with pyrethroids, the probability of resistance development may be high. Population samples of the pollen beetle from four different regions representing a range of Finnish rapeseed growing practices were collected, and tested for pyrethroid resistance. Region 1 had a history of intensive rapeseed growing for about 30 years, in region 4 no rapeseed had ever been grown (reference region), and regions 2 and 3 represented differing intermediates in growing intensity (proportion of growing area allocated to rapeseed) and growing history. A standard dip test with lambda-cyhalothrin was used in a dilution series with ten different concentrations. Some of the dipped beetles were also weighed. Insecticide susceptibility in the populations collected from region one differed significantly from the others: 60% of those populations survived the standard dose. There was no difference in the median weight of surviving and dead individuals in the most resistant population, while in the most susceptible population the size of individual beetles significantly affected the probability of death by the insecticide treatment.  相似文献   

8.
The pollen beetle is the most important pest in Danish oilseed rape fields. In 2001, we screened a broad range of pollen beetle populations for pyrethroid and dimethoate resistance. A standard dip-test was used to test insecticide resistance in 18 populations collected from oilseed winter and spring rape fields. The beetles were treated with four different insecticides: the pyrethroids tau-fluvalinate, lambda-cyhalothrin and esfenvalerate, and the organophosphate dimethoate. The results show that up to 99% of the pollen beetles survived Danish standard doses of pyrethroids and up to 36% of the beetles survived standard doses of dimethoate.  相似文献   

9.
Laboratory studies of the cotoxicity of a pyrethroid insecticide, fenvalerate, and several organophosphorus insecticides against the two-spotted spider mite, Tetranychus urticae Koch, showed that a useful degree of potientation of toxicity occurred. The most effective combination of fenvalerate and azinphos-methyl was found to be a 1:1 ratio. Phosphates and phosphorodithioates in combination with fenvalerate were more toxic than phosphoromonothioates. The results suggest a practical method of improving the acaricidal activity of pyrethroid insecticides.  相似文献   

10.
Widespread use of Bt crops for control of lepidopterous pests has reduced insecticide use and provided the tarnished plant bug the opportunity to become a serious pest on mid-South cotton. Organophosphate insecticides have predominantly been used against plant bugs in recent years due to the reduced efficacy of other insecticides. In this study, a biochemical approach was developed to survey enzymatic levels associated with organophosphate resistance levels in field populations of the tarnished plant bug. Forty-three populations were collected from the delta areas of Arkansas, Louisiana, and Mississippi. Three esterase substrates and one substrate each of glutathione S-transferase (GST) and acetylcholinesterase (AChE) were used to determine corresponding detoxification enzyme activities in different populations. Compared to a laboratory susceptible colony, increases up to 5.29-fold for esterase, 1.96-fold for GST, and 1.97-fold for AChE activities were detected in the field populations. In addition to the survey of enzyme activities among the populations, we also examined the susceptibility of major detoxification enzymes to several inhibitors which could be used in formulations to synergize insecticide toxicity against the target pests. As much as 52-76% of esterase, 72-98% of GST, and 93% of AChE activities were inhibited in vitro. Revealing variable esterase and GST activities among field populations may lead to a better understanding of resistance mechanisms in the tarnished plant bug. This study also reports effective suppression of detoxification enzymes which may be useful in future insecticide resistance management program for the tarnished plant bug and other Heteropteran pests on Bt crops.  相似文献   

11.
北疆地区棉蚜对不同杀虫剂敏感度水平测定   总被引:4,自引:0,他引:4  
为了解北疆不同地区棉蚜种群对不同类型杀虫剂的敏感度水平,科学指导北疆地区棉蚜的化学防治,利用FAO推荐的叶片浸渍法(1980)测定北疆地区4个棉蚜田间种群对4类杀虫剂的敏感性.结果表明,新农大种群对杀虫剂的敏感水平最高,不同类型杀虫剂的毒力大小顺序为:新烟碱类>有机磷类>抗生素类>拟除虫菊酯类.安宁渠种群较石河子种群更为敏感.石河子垦区内的两个不同种群对菊酯类处于相对敏感状态;对有机磷类产生了明显抗药性,147团种群对辛硫磷的相对抗性倍数为951.8倍,新湖农场种群更达到了1236.9倍;147团种群和新湖种群对啶虫脒亦产生了明显的抗药性,相对抗性倍数分别为134.4倍和270.0倍,但对吡虫啉的敏感度较高.石河子垦区应限制使用新烟碱类的啶虫脒和有机磷类杀虫剂,以减缓棉蚜抗性的发展.  相似文献   

12.
Pollen beetle, Meligethes aeneus F. (Coleoptera: Nitidulidae) is a major univoltine pest of oilseed rape in many European countries. Winter oilseed rape is cultivated on several million hectares in Europe and the continuous use of pyrethroid insecticides to control pollen beetle populations has resulted in high selection pressure and subsequent development of resistance. Resistance to pyrethroid insecticides in this pest is now widespread and the levels of resistance are often sufficient to result in field control failures at recommended application rates. Recently, metabolic resistance mediated by cytochrome P450 monooxygenases was implicated in the resistance of several pollen beetle populations from different European regions. Here, we have also investigated the possible occurrence of a target-site mechanism caused by modification of the pollen beetle para-type voltage-gated sodium channel gene. We detected a single nucleotide change that results in an amino acid substitution (L1014F) within the domain IIS6 region of the channel protein. The L1014F mutation, often termed kdr, has been found in several other insect pests and is known to confer moderate levels of resistance to pyrethroids. We developed a pyrosequencing-based diagnostic assay that can detect the L1014F mutation in individual beetles and tested more than 350 populations collected between 2006 and 2010 in 13 European countries. In the majority of populations tested the mutation was absent, and only samples from two countries, Denmark and Sweden, contained pollen beetles heterozygous or homozygous for the L1014F mutation. The mutation was first detected in a sample from Denmark collected in 2007 after reports of field failure using tau-fluvalinate, and has since been detected in 7 out of 11 samples from Denmark and 25 of 33 samples from Sweden. No super-kdr mutations (e.g. M918T) known to cause resistance to pyrethroids were detected. The implications of these results for resistance management strategies of pollen beetle populations in oilseed rape crops are discussed.  相似文献   

13.
The inhibitory effect on the spread of viruses in lilies viz., tulip breaking virus (TBV; nonpersistently aphid-borne, potyvirus,) lily symptomless virus (LSV; non-persistently alphidborne, carlavirus), and lily virus X (LVX; potexvirus of unknown etiology), was studied of brands of mineral oil (Luxan oil H and Duphar-7E oil) and synthetic pyrethroid insecticides (l-cyhalothrin and deltamethrin), and a nematicide (aldicarb) in crops in which virus-infected plants were present as virus sources. The spread of TBV and LSV were controlled by sprays of mineral oil and insecticide, while that of LSV was also limited by the soil-applied nematicide. The spread of LVX was reduced by the insecticides and, not effectively by the mineral-oil spraying, by which data the mode of transmission may be presumed to be by an insect in the persistent or semi-persistent manner.Mixtures of mineral oil and pyrethroid were more effective in the reduction of spread of TBV and LSV than either components tested alone. The mineral oil was the most effective component in the mixtures in which pyrethroid added a slight extra effect. The addition of pyrethroid did not mask either the lower efficacy of the oil brand Duphar-7E oil, or the diminished inhibitory effect of low dosages of oil. The normal rate of mineral oil gave similar control to that of a mixture of mineral oil at half rate plus the pyrethroid at full dosage. Low rates of oil, or even synthetic pyrethroids alone may be used on cultivars which suffer of the loss of bulb weight by the use of normal or decreased rates of oil. Weekly sprays were more effective than fortnightly sprays. The rate of control by the weekly sprays ranged between 90 and 95% for Luxan oil H at half dosage plus the full rate of pyrethroid. Weekly sprayed synthetic pyrethroids alone onto the virus sources and the plants to be infected gave 60–70% control. The weight ratios tended to be slightly reduced if the half dosage of the efficient Luxan oil H was used. Factors which affect the control of the air-borne field spread of viruses by mineral oils and synthetic pyrethroid insecticides in lilies are discussed.  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.
The tarnished plant bug (TPB) has increasingly become an economically important pest of cotton. Heavy dependence on insecticides, particularly organophosphates and pyrethroids, for TPB control facilitated resistance development to multiple classes of insecticides. To better understand resistance and explore ways to monitor resistance in field populations, this study examined acephate susceptibility and the activities of two major detoxification enzymes in nine field populations collected in the Delta region of Mississippi and Arkansas in 2010. Two Arkansas populations from Reed and Backgate had 3.5- and 4.3-fold resistance to acephate, as compared to a susceptible laboratory strain. Extensive planting of cotton and heavy chemical sprays is a major driving force for resistance development to acephate in Mid-south cotton growing areas. Reduced susceptibility to acephate was highly correlated with elevated esterase activities. The acephate-resistant populations from Backgate, Lula, and Reed consistently had higher (up to 5.3-fold) esterase activities than susceptible populations. Regression analysis of LC50s with kinetic esterase activities revealed a significant polynomial quadratic relationship with R2 up to 0.89. Glutathione S-transferase (GST) also had elevated activity in most populations, but the variations of GST activities were not significantly correlated with changes of acephate susceptibility. Finally, examination of esterase and GST inhibitors indicated that suppression rates (up to 70%) by two esterase inhibitors in 2010 were slightly lower than those detected in 2006, and ethacrynic acid (EA) inhibited GST effectively in both years. Two other GST inhibitors (sulfobromophthalein and diethyl maleate) displayed significantly lower suppression rates in 2010 than those detected in 2006, suggesting a potential genetic shift in pest populations and a necessity of continued monitoring for insecticide resistance with both bioassay and biochemical approaches. Results indicated that using major detoxification enzyme activities for resistance monitoring may provide insight into acephate resistance in field populations of TPB.  相似文献   

16.
BACKGROUND: The cabbage whitefly, Aleyrodes proletella L., is emerging as a significant pest of field brassica crops in certain regions of the United Kingdom. In order to investigate the contribution of pesticide resistance to this phenomenon, A. proletella populations were sampled from five different areas in England in 2008 and 2009. Adult residual leaf‐dip bioassays were carried out using pyrethroid and neonicotinoid insecticides. RESULTS: Significant resistance to pyrethroids was found in multiple samples collected from two areas. No evidence of cross‐resistance to neonicotinoids was found in a subset of the pyrethroid‐resistant populations. While the patterns of resistance to different pyrethroids were broadly correlated, the magnitude of resistance factors differed substantially. Survival of strains at a putative diagnostic concentration of lambda‐cyhalothrin was found to provide a guide to their LC50. Significant differences in LC50 were found when different brassica crops were used in the bioassay, although the resistance patterns between strains were maintained. CONCLUSION: Reduced susceptibility to multiple pyrethroid insecticides exists in populations of A. proletella in the United Kingdom, corresponding to recent major outbreaks. The mechanism(s) of resistance are yet to be determined, but molecular structural differences in pyrethroids probably influence the magnitude of cross‐resistance within this group of insecticides. Copyright © 2011 Society of Chemical Industry  相似文献   

17.
Wheat insect pests and the beneficial arthropod populations were assessed using sweep net across a large scale winter wheat field in Bad Lausick (Free State of Saxony, Germany) before and after insecticide applications. The insecticides used were Karate (pyrethroid), Biscaya (neonicotinoid) and NeemAzal T/S (botanical insecticide). The tested compounds were sprayed twice during the early season growth stage (Elongation- GS 32) and at the heading stage (GS 55), and their effects were evaluated on wheat insect pests. The side effects of these insecticides on associated natural enemies were also studied. Monitoring was conducted for 4 weeks after each treatment. Cereal aphids, thrips, leafhoppers, cereal leaf beetles, cereal bugs and also many natural enemies such as predators (lady beetles, lacewings, syrphids, dance flies and spiders) and parasitoids (parasitic wasps) were surveyed. The dose of these insecticides resulted in reductions of wheat insect and natural enemy populations and this reduction was corrected based on Abbott equation. The results showed that Karate is correlated with the highest percentage reduction (79.5 %) to wheat insect pests. Karate use also resulted in a percentage reduction to natural enemies (30–60 %). Biscaya and NeemAzal T/S is correlated with an equivalent mortality percents (50–65 %) to wheat insect pests and resulted in a smaller percentage reduction of natural enemies (10–40 %) compared to Karate. Thrips and cereal bugs were more affected than leafhoppers. Lacewings and dance flies were more susceptible; while spider, syrphids and parasitoid wasps were more tolerant. Compatibility between natural insecticides and natural enemies is highly required to keep the environment clean.  相似文献   

18.
BACKGROUND: The spotted bollworm Earias vittella (Fab.) is a serious pest of cotton and okra in Pakistan. Owing to persistent use of insecticides, this pest has developed resistance, especially to pyrethroids. The present studies aimed at determining the extent of resistance to pyrethroid, organophosphorus and new chemical insecticides in Pakistani populations of E. vittella. RESULTS: Field populations of E. vittella were monitored at Multan, Pakistan, from 1999 to 2007 for their resistance against six pyrethroid, four organophosphorus and six new chemical insecticides using a leaf‐dip bioassay. Of the pyrethroids, resistance was generally low to zeta‐cypermethrin and moderate to high or very high to cypermethrin, deltamethrin, esfenvalerate, bifenthrin and lambda‐cyhalothrin. Resistance to organophosphates chlorpyrifos, profenofos, triazophos and phoxim was recorded at very low to low levels. Among new chemicals, E. vittella had no or a very low resistance to spinosad, emamectin benzoate and methoxyfenozide, a very low to low resistance to abamectin, a very low to moderate resistance to indoxacarb and a moderate resistance to chlorfenapyr. CONCLUSION: The results indicate a lack of cross‐resistance between pyrethroid and organophosphorus insecticides in E. vittella. Rotation of insecticides showing no, very low or low resistance, but belonging to different insecticide classes with unrelated modes of action, may prevent or mitigate insecticide resistance in E. vittella. Copyright © 2009 Society of Chemical Industry  相似文献   

19.
Different insecticides have been tested for the control of the olive bark beetle, Phloeotribus scarabaeoides Bern. This scolytid can be managed at two points in its biological cycle: in pruned logs, where it excavates reproduction galleries, or in living trees, after emergence from the logs, where it digs feeding galleries. In mortality laboratory bioassays, the efficiency of organophosphorus insecticides has been ranked as follows: chlorpyrifos + dimethoate < formothion < methidathion. Formothion and methidathion, the two most efficient, were sprayed on olive logs together with a pyrethroid insecticide, deltamethrin, and a formulation which combined an organophosphorus (fenitrothion) and a pyrethroid (cypermethrin) insecticide. Deltamethrin inhibited the excavation of new reproduction galleries and induced a repellent effect on the olive pest. In contrast, none of the organophosphorus insecticides or the combination, fenitrothion + cypermethrin, were able to control the olive bark beetle. In olive trees, deltamethrin controlled this olive pest without showing the repellent effect observed for logs. Ethylene, a plant hormone, has been reported as an attractant for the olive bark beetle. The use of dispensers which released ethylene increased the number of P. scarabaeoides approaching the treated olive trees, thus favouring its use in a lure-and-trap control system.  相似文献   

20.
为明确陕西关中地区麦蚜田间种群对杀虫剂的抗药性现状,采用浸叶法测定了兴平、礼泉、凤翔、岐山、扶风地区麦田禾谷缢管蚜种群对高效氯氰菊酯、溴氰菊酯、吡虫啉、异丙威、毒死蜱、阿维菌素、氟啶虫胺腈等7种杀虫剂的抗性水平。结果表明,禾谷缢管蚜对高效氯氰菊酯的抗性水平最高,其中凤翔种群对高效氯氰菊酯达到高水平抗性(抗性倍数为72.5),岐山和扶风种群对该药产生中等水平抗性(抗性倍数分别为31.4、29.9);5个地区的禾谷缢管蚜对溴氰菊酯、吡虫啉、毒死蜱、异丙威和阿维菌素的抗性水平较低,表现为敏感、敏感性下降或者低抗性;5个地区的试虫对氟啶虫胺腈均表现为敏感。分析认为,高效氯氰菊酯不适合用于关中地区禾谷缢管蚜防治,氟啶虫胺腈作为一种新型杀虫剂,可以在该虫防治中推广使用,吡虫啉、阿维菌素等其他几种杀虫剂可以在禾谷缢管蚜的防治中交替使用。  相似文献   

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