阿维菌素与其他3种药剂复配对朱砂叶螨的联合作用

室内采用叶片残毒法测定了阿维菌素、丁醚脲、哒螨灵和炔螨特对朱砂叶螨雌成螨的毒力及其复配剂的联合作用。结果表明,以阿维菌素为主干药剂,与其他3种杀螨剂复配对朱砂叶螨雌成螨的增效作用显著,相同浓度下复配剂显著优于各单剂,其中,阿维菌素和丁醚脲(1∶1、1∶49)、阿维菌素和哒螨灵(1∶19、1∶29)、阿维菌素和炔螨特(1∶1、1∶2、1∶4、1∶39)增效作用显著,共毒系数分别为350.9、488.4、465.9、582.5、349.7、350.5、436.1、452.6。阿维菌素与其他3种杀螨剂复配可有效克服或延缓害螨抗性的产生,并且可以提高药效、降低成本,在害螨防治中极具应用前景和开发潜力。     

Resistance risk assessment: realized heritability of resistance to methrin,abamectin, pyridaben and their mixtures in the spider mite,Tetranychus cinnabarinus

The heritability of resistance has an important bearing on the management of pest resistance, especially for evaluating the sustainability of a chemical on a particular pest population. The susceptibility of pests to insecticides may change depending on the selection pressure of these compounds on populations. Tetranychus cinnabarinus, a very important mite pest of many crops in China, was continuously selected with methrin, abamectin, pyridaben and mixtures of pyridaben and abamectin (pyidaben:abamectin?=?7.4:0.1?m/m), and methrin and abamectin (methrin:abamectin?=?8.9:0.1?m/m). After 16 generations, the resistance increased to 25.8-, 3.7-, 1.3-, 4.0- and 2.5-fold to methrin, abamectin, pyridaben, pyridaben?+?abamectin and methrin?+?abamectin, respectively. The more generations selected, the higher was the resistance level, except in the case of the strain selected with pyridaben. The realized heritabilities of resistance to methrin, abamectin, pyridabe, pyridaben?+?abamectin and methrin?+?abamectin were: 0.20, 0.15, 0.03, 0.18 and 0.08, respectively. Higher values of heritability occurred during the second eight generations selected than through the first eight generations except in the case of the strain selected with the mixture pyridaben?+?abamectin.     

8种杀螨剂对马铃薯朱砂叶螨的防治效果

为了筛选在西北旱作区针对马铃薯朱砂叶螨的最佳防治药剂, 选择了8种杀螨剂进行两年的田间药效试验。结果表明, 24%螺螨酯悬浮剂(SC)处理下的马铃薯单株块茎数最高, 螨株率最低, 并且叶片SPAD值及光合参数值最高, 8种药剂中, 24%螺螨酯SC、43%联苯肼酯SC、2%阿维菌素SC、11%乙螨唑SC和73%炔螨特乳油(EC)对马铃薯朱砂叶螨防效高于80%, 可作为防治马铃薯朱砂叶螨的药剂。     

朱砂叶螨阿维菌素抗性品系选育及适合度研究

为研究朱砂叶螨抗性适合度,在抗性选育基础上实验室组建了朱砂叶螨相对敏感品系、抗阿维菌素品系在豇豆和棉花上的生命表(26℃),比较了相对敏感品系和抗性品系在两种寄主上发育历期、繁殖力及种群参数的差异.结果表明:连续汰选42代,朱砂叶螨对阿维菌素(乳油制剂)产生约8.7倍抗性;与相对敏感品系相比,抗性品系在棉花上若螨期缩短0.55天、世代历期延长0.88天,平均产卵量无显著差异;在豇豆上卵期缩短1.71天,若螨期延长0.41天,世代历期缩短2.06天,平均产卵量减少84.29粒/雌.抗性品系在棉花和豇豆上的相对适合度分别为0.89和0.58,表明该螨产生抗药性后,存在适合度缺陷.     

Fumigant toxicity of lemon eucalyptus oil constituents to acaricide-susceptible and acaricide-resistant Tetranychus urticae

BACKGROUND: This study was aimed at assessing the fumigant toxicity of 14 essential oil constituents from lemon eucalyptus, Eucalyptus citriodora Hook, and another ten known compounds to females of acaricide‐susceptible, chlorfenapyr‐resistant, fenpropathrin‐resistant, pyridaben‐resistant and abamectin‐resistant strains of Tetranychus urticae Koch. RESULTS: Menthol (LC₅₀, 12.9 µg cm^?3) was the most toxic compound, followed by citronellyl acetate (16.8 µg cm^?3), against the susceptible females. High toxicity was also produced by β‐citronellol, citral, geranyl acetate and eugenol (LC₅₀, 21.7–24.6 µg cm^?3). The fumigant toxicity of these compounds was almost identical against females from either of the susceptible and resistant strains, indicating that the compounds and acaricides do not share a common mode of action or elicit cross‐resistance. CONCLUSION: Global efforts to reduce the level of highly toxic synthetic acaricides in the agricultural environment justify further studies on materials derived from lemon eucalyptus oil, particularly menthol and citronellyl acetate, as potential acaricides for the control of acaricide‐resistant T. urticae as fumigants with contact action. Copyright © 2011 Society of Chemical Industry     

朱砂叶螨的抗药性选育及其解毒酶活性研究

在室内模拟田间药剂的选择压力,用阿维菌素和甲氰菊酯对朱砂叶螨Tetranychus cinnabarinus 进行逐代处理,以选育其抗药性品系。阿维菌素品系选育至42代,抗性增长到8.7倍,甲氰菊酯品系选育至40代,抗性增长到68.5倍。阿维菌素抗性品系羧酸酯酶(CarE)、谷胱甘肽-S-转移酶(GSTs)、多功能氧化酶(MFO)的活性分别为敏感品系的2.7、3.4和1.4倍,差异达显著水平。推测3种解毒酶活性显著升高是朱砂叶螨对阿维菌素产生抗性的重要原因。甲氰菊酯抗性品系GSTs的活性为敏感品系的2.8倍,差异显著,表明该抗性品系的形成与GSTs活性增强有关。羧酸酯酶动力学测定结果表明,朱砂叶螨阿维菌素抗性品系体内存在变构的羧酸酯酶。     

重庆潼南朱砂叶螨田间抗性监测及其抗性机制分析

本研究通过生物测定检测了重庆潼南田间朱砂叶螨种群对5种杀虫杀螨剂的抗药性,并测定了主要代谢酶活性及抗性相关基因的表达量。抗性监测结果显示,朱砂叶螨对联苯肼酯和哒螨灵表现为中等水平抗性,对阿维菌素、丁氟螨酯和甲氰菊酯为低水平抗性。代谢酶活性检测结果显示:田间种群的P450和GST活性明显提高,且多个相关基因的表达也显著上调,而CarE的活性没有显著变化。综上所述,重庆潼南田间朱砂叶螨种群已对联苯肼酯、哒螨灵、阿维菌素、丁氟螨酯和甲氰菊酯产生了不同程度的抗药性,P450和GST活性提高和有关基因过表达是抗性产生的主要原因。     

The sodium channel gene in Tetranychus cinnabarinus (Boisduval): identification and expression analysis of a mutation associated with pyrethroid resistance

BACKGROUND: The carmine spider mite (CSM), Tetranychus cinnabarinus, is the most harmful mite pest of various crops and vegetable plants. Pyrethroid insecticide fenpropathrin has been used to control insects and mites worldwide, but CSM has developed resistance to this compound. RESULTS: Three synergists together eliminated about 50% resistance against fenpropathrin in the CSM. A point mutation was identified from the sodium channel gene of fenpropathrin‐resistant CSM (FeR) by comparing cDNA sequences between FeR and susceptible (S) sodium channel genes, which caused a phenylalanine (F) to isoleucine (I) change at amino acid 1538 position in IIIS6 of the sodium channel and has been proven to confer strong resistance to pyrethroid in other species. The mRNA expression of the sodium channel gene in the FeR and abamectin‐resistant strain (AbR), which was included as a control, were both relatively lower than in the S. CONCLUSION: These results demonstrate that a mutation (F1538I) is present in the sodium channel gene in FeR of CSM, likely playing an important role in fenpropathrin resistance in T. cinnabarinus, but that decrease in the abundance of sodium channel did not confer this resistance. The F1538I mutation could be used as a molecular marker for detecting kdr resistance in Arachnida populations. Copyright © 2011 Society of Chemical Industry     

Effect of imidacloprid on the reproduction of acaricide-resistant and susceptible strains of Tetranychus urticae Koch (Acari: Tetranychidae)

Occasional reports linking neonicotinoid insecticide applications to field population outbreaks of the two-spotted spider mite, Tetranychus urticae Koch, have been a topic of concern for integrated pest management (IPM) programmes, particularly in apples. In order to shed light on the factors which may contribute to the occasional field population increase of T. urticae following the application of neonicotinoid insecticides, greenhouse experiments have been set up. Four different T. urticae strains, namely GSS (acaricide-susceptible), WI (organophosphate-selected), USA (a largely uncharacterised strain) and Akita (METI (mitochondrial electron transport inhibitor) acaricide-resistant and cross-resistant to dicofol), were compared for their fecundity without insecticide treatment and for their ovipositional response to foliar and drench applications of the field-relevant dose of imidacloprid (100 mg litre(-1)). Without insecticide treatment, strain GSS laid significantly more eggs (162.50 (+/- 5.43)) than the multiple resistant strain Akita (139.90 (+/- 5.54)) during a 16 day oviposition period. With imidacloprid treatment the highest effect was observed with GSS, with a significantly reduced number of eggs in drench (143.40 (+/- 4.22)) and foliar (144.60 (+/- 5.85)) applications. For strains Akita and USA, no significant differences were observed in oviposition between imidacloprid treatments and controls. The proportion of F1 female offspring decreased significantly with drench application for GSS and WI, while no differences were observed among strains in the survival of F1 immature stages, except for strain USA. The viability of eggs was relatively high (from 82.9 (+/- 4.5)% for USA to 95.2 (+/- 1.2)% for GSS) and not affected by imidacloprid treatments.     

10%甲氰·阿维乳油配方的筛选及其对朱砂叶螨的联合作用

通过对助剂和配方的筛选,确定10%甲氰·阿维乳油的溶剂为20∶1(质量比,下同)的二甲苯与乙酸乙酯混合溶液,乳化剂为30∶1的QR-9与QR-11混合物,其添加量为60 mg/g。采用玻片浸渍法测定9种不同配比复配剂对朱砂叶螨Tetranychus cinnabarinus (Boisduval)的联合毒力作用。结果表明:9种复配剂对朱砂叶螨的共毒系数均在200以上,表明两种单剂复配具有显著的增效作用,其中以甲氰菊酯与阿维菌素按有效成分97∶3的比例复配,其增效作用最为显著,共毒系数高达357.7,为最佳配比。     

Comparative acaricide susceptibility and detoxifying enzyme activities in field-collected resistant and susceptible strains of Tetranychus urticae

A field-collected strain (MR-VL) of the two-spotted spider mite, Tetranychus urticae Koch, exhibited strong resistance to bifenthrin, dicofol and fenbutatin oxide in comparison with a susceptible laboratory strain (LS-VL). The MR-VL strain was screened for cross-resistance with several currently used acaricides. Cross-resistance was detected with clofentezine (RR = 2631), dimethoate (RR = 250), chlorfenapyr (RR = 154), bromopropylate (RR = 25), amitraz (RR = 17), flucycloxuron (RR = 15) and azocyclotin (RR = 7). Abamectin, acequinocyl, bifenazate, tebufenpyrad and spirodiclofen did not show any signs of cross-resistance. Enhanced detoxification by increased activity of mono-oxygenases (MO) and esterases is at least partially responsible for the observed resistance and cross-resistance. MO assays with 7-ethoxycoumarin (7-EC) were optimised and 7-ethoxy-4-trifluoromethylcoumarin (7-EFC), a new MO-substrate, was evaluated for the first time in T urticae and proved to be a good alternative to 7-EC. Approximately 3- and 4-fold higher MO activity was detected with 7-EFC and 7-EC respectively in the MR-VL strain. Kinetic parameters of general esterase assays with 4-nitrophenyl acetate and 1-naphthyl acetate as substrate indicated that more esterases were present in the MR-VL strain. A first attempt was made to classify the esterases present in T urticae. Acetyl-, aryl- and carboxyl-esterases were detected with the use of inhibitors after separation by native PAGE. Glutathione-S-transferases did not seem to play any role in the observed resistance and no differences were detected when the general oxidative capacities of the two strains were compared.     

Dicofol resistance in Tetranychus cinnabarinus: resistance and stability of resistance in populations from Antalya, Turkey

Resistance against dicofol was investigated in the carmine spider mite, Tetranychus cinnabarinus. Higher resistance levels were detected by leaf residual bioassays than by topical bioassays, both done using a Potter spray tower, in almost all populations of T cinnabarinus examined from Antalya, Turkey. For instance, the resistance level at LC₉₅ was 17.5‐fold in topical bioassays but 58.9‐fold in leaf residual bioassays for the population collected from greenhouses in the Topçular district. There were differences of resistance levels at LC₉₅, ranging between 2.6‐ and 23.9‐fold using topical bioassays and between 5.0‐ and 58.9‐fold in residual bioassays, in populations collected from greenhouses from various districts. Populations from cotton showed lower resistance levels against dicofol than populations from greenhouses. Resistance to dicofol at LC₅₀ as indicated by topical and residual bioassays increased 19.7‐ and 100.7‐fold, respectively, in a colony from the laboratory strain of T cinnabarinus selected with dicofol alone for 16 cycles. However, the dicofol resistance at LC₅₀ increased 19.4‐ and 52.0‐fold in another colony selected in rotation with dicofol and tetradifon for six and eight cycles, respectively. The changes in resistance to dicofol 5 months after the selection ceased were as follows: in the colony selected for dicofol alone, using topical and residual bioassays, the resistance levels at LC₅₀ decreased to 11.7‐ and 99.1‐fold, respectively, and in the colony selected in rotation with dicofol and tetradifon to 10.8‐ and 15.8‐fold, respectively. © 2001 Society of Chemical Industry     

农药环境影响指数(EIQ)在农作物病虫害防治工作中的应用

贯彻绿色植保理念,必须科学地监测和最大限度地减少农药对人类健康和生态环境的负面影响。本文介绍了农药环境影响指数(EIQ),讨论了其在农作物病虫害防治工作中应用与局限性。     

朱砂叶螨对两种杀螨剂的抗性遗传力及风险评估

在室内抗性培育的基础上,应用数量遗传学中的域性状分析法研究了朱砂叶螨对甲氰菊酯和阿维菌素两种杀螨剂的抗性现实遗传力,并对两种药剂在不同杀死率下,朱砂叶螨抗性发展的速率进行了预测。结果表明,用甲氰菊酯、阿维菌素分别连续汰选16、18代后,朱砂叶螨对两者的抗性分别为28.61和4.36倍,抗性现实遗传力分别为0.2685和0.1385。在室内选择条件下,杀死率为50％～90％时,要获得10倍抗性,甲氰菊酯需要约13～6代,阿维菌素需要约28～13代。生物源农药阿维菌素的抗性风险明显低于菊酯类药剂甲氰菊酯。试验结果为朱砂叶螨抗性治理提供了理论依据。     

蒜和葱上二斑叶螨的发生为害及其抗药性监测

二斑叶螨寄主植物范围极广, 但其对百合科蔬菜造成危害的研究报道极少?本研究采集了来自北京海淀百合科蔬菜蒜和葱上的2个二斑叶螨种群, 生物测定结果显示, 2个种群对阿维菌素呈现出极高水平抗性, 对哒螨灵为中等以上抗性(LC50>5 000 mg/L), 对新型药剂联苯肼酯?虫螨腈和腈吡螨酯也表现出中等到高水平抗性?抗性基因突变频率检测发现, 与阿维菌素抗性相关基因G314D和G326E位点以及和哒螨灵抗性相关基因H92R位点的突变频率均高达100%, 为纯合抗性种群?因此, 本研究所测试的2个二斑叶螨种群对阿维菌素和哒螨灵单剂的敏感性极低, 需慎重选用这2种药剂, 而3种新型杀螨剂联苯肼酯?虫螨腈和腈吡螨酯在田间需轮换使用?     

真桑钝绥螨捕食朱砂叶螨的实验种群生命表及捕食作用

为评价真桑钝绥螨Amblyseius makuwa Ehara防治害螨的可能性,本试验在(25±1)℃、RH 80%±5%、光周期16L:8D的条件下,组建了真桑钝绥螨以朱砂叶螨Tetranychus cinnabarinus Boisduv为食的实验种群生命表,研究了真桑钝绥螨雌成螨对朱砂叶螨卵、若螨和雌成螨的捕食作用。结果表明,真桑钝绥螨以朱砂叶螨为食,未成熟期发育历期分别为卵期1.90 d,幼螨期0.62 d,前若螨期0.82 d,后若螨期1.26 d。试验条件下真桑钝绥螨净增殖率为11.80,内禀增长率为0.175,世代平均周期为14.12 d,周限增长率为1.191,种群倍增时间为3.96 d,雌成螨日均产卵量为1.22粒,平均总产卵量为22.12粒。真桑钝绥螨对朱砂叶螨3个螨态的捕食功能反应均属于HollingⅡ型圆盘方程,拟合圆盘方程显示真桑钝绥螨对朱砂叶螨卵的捕食数量最大,其次为若螨和雌成螨,a/Th值分别为12.5162、5.8730和4.4009。综上研究结果,真桑钝绥螨具备优良天敌的基本特性,是朱砂叶螨的潜在天敌之一。     

新型杀螨剂-乙唑螨腈对草莓二斑叶螨防效及安全性研究

以二斑叶螨为Tetranychus urticae Koch试虫,采用田间药效试验的方法,研究了乙唑螨腈等6种杀螨剂对二斑叶螨的田间防效及对草莓的安全性。以期为草莓二斑叶螨防控提供高效、安全的杀螨剂。结果表明:30%乙唑螨腈悬浮剂速效性与持效性最好,药后1d的防效为91.80%,14d防效为95.56%;20%丁氟螨酯悬浮剂和100g/L联苯菊酯乳油2种药剂的速效性较好,持效性较差,药后Id防效在83%-89%,药后14d的防效在27%~46%;43%联苯肼酯悬浮剂在药后3d的防效最高,达到87.87%;1.8%阿维菌素乳油在药后1~14d防效在36%-72%之间。73%炔螨特乳油在365mg/L浓度下对草莓叶片产生药害,其它药剂对草莓安全。     

山楂叶螨抗药性及混配增效作用

采用载玻片浸渍法测定了山西省忻州、晋中、运城地区山楂叶螨种群对9种杀螨剂的抗药性水平.测定结果表明:忻州地区种群对甲氰菊酯和三氯杀螨醇表现中抗,抗性指数FR分别为17.79和31.93倍,对水胺硫磷和毒死蜱表现低抗,FR值分别为7.74和5.35倍;晋中地区种群对水胺硫磷、甲氰菊酯和三氯杀螨醇均表现中抗,FR值为22.42～33.00倍,而运城地区种群对这3种药剂产生了高抗,FR值分别为135.05、41.53和1714.01倍;运城地区种群对毒死蜱表现中抗,FR值为34.49倍;晋中和运城地区种群对双甲脒表现低抗,FR值分别为5.15和6.89倍;3个种群对阿维菌素、苯丁锡、三唑锡和四螨嗪仍相对敏感.混配增效作用测定结果表明,阿维菌素与甲氰菊酯1:20、1:10、1:5组合以及阿维菌素与三氯杀螨醇1:20、1:10组合均具有明显增效作用,共毒系数为189.63～363.30,其中阿维菌素与甲氰菊酯1:20和1:10组合以及阿维菌素与三氯杀螨醇1:20组合是比较理想的混配组合.     

Variations in acaricidal effect of wettable sulfur on Tetranychus urticae (Acari:Tetranychidae): effect of temperature,humidity and life stage

Under laboratory conditions, the acaricidal effect of wettable sulfur is influenced by climatic conditions and the stage of development of Tetranychus urticae. Its ovicidal effect results from the combined action of temperature and relative humidity (RH). Wettable sulfur becomes effective at 27.5 degrees C and 75% RH. Beyond this threshold, the acaricidal effect increases with rising temperature or humidity, to become complete at a temperature of 35 degrees C and 90% RH. Within the range of temperatures and humidities 20 degrees C/30% RH and 35 degrees C/90% RH the mortality of immatures (from protonymphs to teleiochrysalis) was total. Under similar experimental conditions, females usually died before the end of the experiment. Temperature and relative humidity increased the adulticidal potential of wettable sulfur. The fecundity of the sulfur-treated females and the viability of their progeny was found to depend on temperature and RH. According to the same climatic conditions, eggs were less susceptible than females, which were in turn less susceptible than juvenile stages.