二斑叶螨对螺螨酯抗药性及对18种杀螨剂交互抗性

采自甘肃兰州兴隆山公园的二斑叶螨(Tetranychus urticae Koch),用雌雄单系培养敏感品系(S),用螺螨酯处理二斑叶螨种群培养抗性品系(SP R),用室内生测法对二斑叶螨S和SP R品系进行室内毒力测定。结果表明,二斑叶螨对螺螨酯抗性发展初期较慢,中期稳定,后期较快,选育至26代抗性指数(RI)达58.83。SP R对甲氰菊酯、氯氰菊酯有一定的交互抗性,RI分别为11.54和10.03;对苯丁锡、四螨嗪、苦皮藤生物碱、阿维菌素、氯氟氰菊酯、哒螨&#8226;四螨嗪、哒&#8226;水胺硫磷、三唑锡、三氯杀螨醇、哒螨灵、氧化乐果无交互抗性(1＜RI<5.00);对浏阳霉素、毒死蜱、噻螨酮、柴油、哒螨灵、唑螨酯可能存在负交互抗性(RI<1)。     

二斑叶螨对甲氰菊酯和螺螨酯的抗性选育及增效剂的增效作用

［目的］ 探索二斑叶螨对甲氰菊酯和螺螨酯种群的抗性机理和抗性治理途径。 ［方法］ 采用室内生物测定法,以采自兰州兴隆山自然保护区的二斑叶螨为敏感种群（S）,在室内用甲氰菊酯和螺螨酯分别对二斑叶螨进行抗性选育;用增效醚(PBO)、顺丁烯二酸二乙酯(DEM)、磷酸三甲苯酯(TPP)、有机硅、噻酮进行增效作用研究。［结果］二斑叶螨经室内甲氰菊酯和螺螨酯抗性选育45代和30代后,抗性倍数分别达到314.50倍和77.92倍。TPP、PBO、DEM 3种增效剂对二斑叶螨抗甲氰菊酯种群的抗敏增效比分别为12.15、7.78和3.09,推测其抗性机理涉及的主要解毒酶是羧酸酯酶和多功能氧化酶; DEM对二斑叶螨抗螺螨酯种群的抗敏增效比大于TPP和PBO,分别为4.87、3.67和1.91,二斑叶螨对螺螨酯产生抗性机理可能与谷胱甘肽转移酶和羧酸酯酶活性增强有关。有机硅和噻酮对二斑叶螨抗甲氰菊酯和螺螨酯种群的抗敏增效指数比分别为1.38、1.42和1.18、0.92,说明二斑叶螨的抗性与表皮通透性改变关系不密切。 ［结论］ 上述结果可以为二斑叶螨的抗性治理提供依据。     

二斑叶螨对螺螨酯抗性和敏感种群相对适合度的研究

［目的］ 研究二斑叶螨对螺螨酯的抗药性与适合度的关系,为该螨的抗性治理提供科学依据。［方法］ 在室内温度(25±1)℃,相对湿度(70±5)%,光照14 h条件下通过构建实验种群生命表,比较二斑叶螨对螺螨酯抗性种群(R)和敏感种群(S)的生长发育和繁殖特征参数,用净增殖率(R0)来确定抗性种群的生物适合度。［结果］ 二斑叶螨抗性种群的若螨期和全世代较敏感种群分别延长0.92 d和0.82 d;雌螨存活时间较敏感种群缩短3 d;二斑叶螨对螺螨酯抗性种群的相对适合度为敏感种群的0.76倍,存在适合度缺陷。［结论］ 在生产上应注意对螺螨酯的合理使用,以延缓其抗性进程,实现可持续治理。     

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。     

甲氰菊酯和螺螨酯对二斑叶螨实验种群的亚致死效应

在室内研究了甲氰菊酯和螺螨酯亚致死剂量对二斑叶螨实验种群成螨和卵的影响。结果表明,甲氰菊酯亚致死剂量LC10处理成螨后,二斑叶螨的卵期、幼螨期、若螨期、成螨期及寿命均显著缩短,处理卵后各发育历期均显著低于对照;亚致死剂量LC20处理成螨后二斑叶螨的卵期、若螨期、成螨期及寿命均显著缩短,处理卵后各发育历期均低于对照,处理后F1代种群的内禀增长率rm由0.191 9增至0.193 4～0.205 9,对种群有刺激增殖作用。螺螨酯亚致死剂量LC10处理成螨后,卵期、若螨期显著延期长,处理卵后卵期、若螨期、产卵前期均长于对照;亚致死剂量LC20处理成螨后卵期、幼螨期显著延长,处理卵后卵期、若螨期、产卵前期均长于对照,螺螨酯两亚致死剂量处理成螨和卵后成螨期和寿命均缩短,处理后F1代种群的内禀增长率rm由0.191 9降低至0.149 9～0.150 8,对种群有抑制作用。     

二斑叶螨对常用杀螨剂的抗药性测定

采用玻片浸渍法 ,测定了二斑叶螨Tetranychus urticae Koch山东寿光种群 (R1)和山东烟台种群 (R2 )对常用杀螨杀虫剂的抗性 ,与山东泰安相对敏感种群 (S)相比 ,对哒螨灵、高效氯氟氰菊酯和甲氰菊酯 3种药剂的抗性 ,R1分别达 6.67、6.33和 10.36倍 ,R2分别达 26.56、15.4 5和 31.30倍 ,R1和 R2对上述 3种药剂均产生了较高水平的抗药性。另外,R1、R2种群对其它药剂也均表现出了不同程度的抗性现象。     

常用杀螨剂对二斑叶螨敏感种群毒力测定

采用FAO1980年推荐的玻片浸渍法和叶片残毒法,选用12种常用杀螨剂,对二斑叶螨的敏感种群进行了毒力测定。结果表明:杀卵活性依次为尼索朗>除尽>螨死净>螨即死>卡死克>扫螨净>齐螨素>螨克;对雌成螨的毒性依次为齐螨素>霸螨灵>三唑锡>除尽>三氯杀螨醇>螨即死>克螨特>扫螨净>螨克。     

二斑叶螨抗阿维菌素品系选育及其解毒酶系活力变化

采用室内生物测定和生化分析方法, 以采自甘肃兰州国家级森林公园兴隆山的二斑叶螨为敏感品系(SS), 研究二斑叶螨对阿维菌素的抗药性及抗性生化机理。结果表明：在室内用阿维菌素强化筛选24代, 获得了二斑叶螨抗阿维菌素品系(Ab-R24), 抗性指数(resistance index, RI)为321.5。对SS和Ab-R24解毒酶活性的分析表明, Ab-R24品系体内羧酸酯酶(CarE)、乙酰胆碱酯酶(AchE)、酸性磷酸酯酶(ACP)、碱性磷酸酯酶(ALP)、谷胱甘肽S-转移酶(GSTs)和多功能氧化酶(MFO)活性分别是SS品系的1.43、1.18、1.56、1.48、1.55倍和4.02倍, 差异达到显著水平(P < 0.05), 其中MFO的活性上升最为显著。对SS和Ab-R-24解毒酶动力学常数的分析表明, Ab-R-24品系体内AchE、GSTs和MFO的 Km分别是SS品系的1.14、2.31倍和2.58倍; Vmax分别是SS品系的1.19、2.34倍和1.76倍, 差异均达到显著水平(P <0.05)。说明二斑叶螨对阿维菌素抗性增高与MFO活性快速升高有关, AchE和GSTs也参与阿维菌素抗性的形成。     

二斑叶螨混合抗性种群相对适合度的研究

研究了二斑叶螨抗甲氰菊酯、阿维菌素、螺螨酯混合品系(R)和敏感品系(S)的生长发育与生殖情况,比较种群的生物适合度。结果表明:与敏感品系(S)相比,抗性品系各螨态发育历期和产卵量均存在不同程度的下降,抗性品系的净生殖率(R0=12.765 9)远低于敏感品系(R0=42.420 3),相对适合度为敏感品系的0.300 9倍,存在适合度缺陷;其他生命表参数无种群差异。     

20种中草药对二斑叶螨的毒性研究

本文采用联合国粮农组织（FAO）推荐方法研究了20种中草药提取物对二斑叶螨Tethranychus urticaeKoch雌成螨与卵的毒性。研究结果表明大部分中草药提取物对雌成螨和卵显示出程度不等的毒性作用。其中北细辛Asarum heterotropoides var.mandshuricum（Maxim.）Kitag、黄连Coptis chinensis Franch、苦楝子Meliatoosendan Sieb.et Zucc、槟榔Areca catechu L.与苦参Sophora flavescens Ait.对雌成螨和卵均表现出很强的毒性作用,在提取物浓度为10 mg mL1、作用72 h后,雌成螨死亡率为100%;在提取物浓度为10 mg mL1,作用5 d后,卵孵化率小于40%。北细辛表现最为突出,对成螨与卵的LD50分别为0.57 mg mL1（1 d）和0.88mg mL1（5 d）。结果显示,北细辛、黄连与槟榔等中草药具有研究开发为植物源杀螨剂的潜力。     

Synergistic effect of Beauveria bassiana and spirodiclofen on the two-spotted spider mite (Tetranychus urticae)

The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is one of the most important pests in agriculture. Due to its short life cycle and high reproductive rate, this pest has become resistant to most acaricides. Therefore, finding alternative control strategies for this damaging pest is necessary. Application of microbiological agents with minimum concentrations of acaricides is a very suitable tactic in integrated pest management. In the present study, lethal effects of a chemical acaricide – spirodiclofen, and an Iranian strain of the entomopathogenic fungus Beauveria bassiana, were evaluated on different life stages of the two-spotted spider mite on two host plants, bean and cucumber. In the next step, compatibility of acaricide with the fungus was studied regarding conidial germination and vegetative growth of the fungus in the presence of different concentrations of the acaricide. Finally, the acaricide at rates of LC₂₅ with the fungus at LC₅₀ were sprayed on adult female mites. The results showed that immature stages of T. urticae were more susceptible to the acaricide whereas the adults were more susceptible to the fungus. Also, mites reared on cucumber were significantly more susceptible to the acaricide and fungus than those reared on bean. Spirodiclofen and the fungus had a synergistic effect; percentage of mortality for fungus infection was 48.6% and 53.5% on bean and cucumber, respectively, while it was 80.6% on bean and 84.5% on cucumber when the mite was sprayed with both the fungus and the acaricide.     

Acetylcholinesterase point mutations putatively associated with monocrotophos resistance in the two-spotted spider mite

Molecular mechanisms of monocrotophos resistance in the two-spotted spider mite (TSSM), Tetranychus urticae Koch, were investigated. A monocrotophos-resistant strain (AD) showed ca. 3568- and 47.6-fold resistance compared to a susceptible strain (UD) and a moderately resistant strain (PyriF), respectively. No significant differences in detoxification enzyme activities, except for the cytochrome P450 monooxygenase activity, were found among the three strains. The sensitivity of acetylcholinesterase (AChE) to monocrotophos, however, was 90.6- and 41.9-fold less in AD strain compared to the UD and PyriF strains, respectively, indicating that AChE insensitivity mechanism plays a major role in monocrotophos resistance. When AChE gene (Tuace) sequences were compared, three point mutations (G228S, A391T and F439W) were identified in Tuace from the AD strain that likely contribute to the AChE insensitivity as predicted by structure analysis. Frequencies of the three mutations in field populations were predicted by quantitative sequencing (QS). Correlation analysis between the mutation frequency and actual resistance levels (LC₅₀) of nine field populations suggested that the G228S mutation plays a more crucial role in resistance (r² = 0.712) compared to the F439W mutation (r² = 0.419). When correlated together, however, the correlation coefficient was substantially enhanced (r² = 0.865), indicating that both the F439W and G228S mutations may work synergistically. The A391T mutation was homogeneously present in all field populations examined, suggesting that it may confer a basal level of resistance.     

Fitness costs associated with milbemectin resistance in the two-spotted spider mite Tetranychus urticae

The two-spotted spider mite Tetranychus urticae Koch is one of the most important pests of a wide range of crops worldwide. Its control is still largely based on the use of acaricides. However, due to its short life-cycle, high fecundity and arrhenotokous reproduction, it is able to develop resistance to these compounds very rapidly. Preliminary studies for milbemectin resistance in T. urticae showed that, under laboratory conditions, such resistance was unstable in the absence of a selection pressure. The aim of this study was to evaluate the possible fitness costs associated with milbemectin resistance in T. urticae. Comparison of biological traits between resistant and susceptible strains indicated the occurrence of fitness costs associated with milbemectin resistance. The resistant strain showed a longer juvenile development period for females, lower fecundity and a higher proportion of males among the progeny. The figures for net reproductive rate (R ₀), intrinsic rate of natural increase (r _m) and finite rate of increase (λ) were higher in the susceptible strain. The instability of milbemectin resistance can be exploited in resistance management programmes.     

Esterase-mediated bifenthrin resistance in a multiresistant strain of the two-spotted spider mite, Tetranychus urticae

A field-collected multiresistant strain of Tetranychus urticae Koch exhibiting high resistance to bifenthrin was investigated in comparison with a susceptible laboratory strain. The esterase inhibitor S,S,S-tributyl-phosphorotrithioate (DEF) was able strongly to synergise bifenthrin toxicity in the resistant strain. Optimal conditions for determining esterase activities in T. urticae were determined, and a higher esterase activity towards several artificial substrates was found in this resistant strain, which had a preference for hydrolysing 4-nitrophenyl butyrate. Bifenthrin was able to bind the active centres of T. urticae esterases in vitro, as was determined after competition experiments by a Dixon plot, revealing a higher affinity of bifenthrin in the resistant strain. Bifenthrin-hydrolysing activity in the resistant and susceptible strains was examined in vitro and quantified with gas chromatography. A 7.2-fold higher metabolising rate was found in the resistant strain.     

Resistance to bifenthrin and resistance mechanisms of different strains of the two-spotted spider mite (Tetranychus urticae) from Turkey

Nine different strains of the two-spotted spider miteTetranychus urticae Koch (Acari: Tetranychidae) were collected on cotton from Adana, Antalya, Izmir, Manisa and Urfa in Turkey. Their responses to bifenthrin were investigated using conventional bioassay and biochemical assays. LC₅₀ and LC₉₀ values of bifenthrin were determined for all strains by using a residual bioassay with a petri dish-spray tower. Resistance ratios were determined by comparing the samples with a standard susceptible strain, GSS. The resistance ratios of the strains ranged from <1 to 669-fold (at LC₅₀). Of the investigated field strains, only three (two from Adana and one from Urfa) were resistant to bifenthrin. There was a correlation between esterase enzyme activity and bifenthrin resistance according to polyacrylamide gel electrophoresis and microtiter plate assays in the three resistant strains. http://www.phytoparasitica.org posting May 17, 2005.     

棉铃虫对甲氧虫酰肼的抗性遗传力

(δp=0.5),抗性现实遗传力为实际筛选估计值的一半,当杀死率为80%和90%时,棉铃虫对甲氧虫酰肼的抗性增加10倍,分别需要34.48代和27.40代.田间条件下,由于等位基因频率变化、环境变异等因素的影响,抗性增加10倍则需要更长的时间.     

草栖钝绥螨对二斑叶螨的捕食作用

为明确草栖钝绥螨Amblyseius herbicolus对二斑叶螨Tetranychus urticae的控制潜能,在温度分别为19、22、25、28和31℃、相对湿度均为（85±5）%、光周期均为16 L∶8 D条件下测定草栖钝绥螨对二斑叶螨各螨态的捕食偏好性、捕食功能反应及自身干扰反应。结果表明,草栖钝绥螨对二斑叶螨幼螨和第1若螨具有嗜食性,对其捕食选择系数分别为2.22和1.27,均大于1.00,对二斑叶螨卵、第2若螨和雌成螨捕食选择系数分别为0.61、0.68和0.22,均小于1.00。在不同温度条件下,草栖钝绥螨对二斑叶螨各螨态的捕食功能反应均符合HollingⅡ型;在19～31℃范围内,草栖钝绥螨对二斑叶螨各螨态的瞬时攻击率、最大日捕食量和捕食能力均随着温度升高呈先升高后降低的趋势,在28℃时达到最大值;而草栖钝绥螨对二斑叶螨各螨态的处理时间随着温度升高呈先缩短后延迟的趋势,在28℃下处理时间最短。在相同温度下,草栖钝绥螨对二斑叶螨卵、幼螨和第1若螨的捕食作用较强。在有限的捕食空间和二斑叶螨密度固定的条件下,草栖钝绥螨单头捕食量和捕食作用率随其自身密度的增加而逐渐下降,说...     

释放智利小植绥螨防治设施栽培草莓上二斑叶螨

二斑叶螨是为害草莓的重要害螨之一。随着杀虫、杀螨剂的抗药性问题以及在水果上的残留问题日益严重,生物防治成为解决这一问题的重要措施。本文研究了释放智利小植绥螨对温室大棚草莓上二斑叶螨种群的控制作用。结果表明:3个释放密度(240、120、60头/株)的智利小植绥螨对温室草莓上二斑叶螨种群均有很好的防治效果,最高虫口减退率及防效都在80%以上,化学农药43%联苯肼酯SC对二斑叶螨种群的最高防效仅为61.89%;随捕食螨释放量的增加,防治效果也越显著。综合平衡生防成本与防效,推荐释放量为60头/株。     

Incidence and inheritance of resistance to METI-acaricides in European strains of the two-spotted spider mite (Tetranychus urticae) (Acari: Tetranychidae)

A strain of Tetranychus urticae (Koch; Acari: Tetranychidae), collected from hops (Humulus humuli L; Cannabaceae) in England with a short history of tebufenpyrad use, exhibited resistance to four METI (mitochondrial electron transport inhibitor)-acaricides; tebufenpyrad, pyridaben, fenazaquin and fenpyroximate. Resistance factors for these compounds in a microimmersion assay were 46, 346, 168 and 77 respectively, and corresponded to those exhibited by a Japanese METI-acaricide-resistant reference strain. Levels of resistance remained stable without further selection, and selection with tebufenpyrad did not increase them. The UK strain was also resistant (c 6-fold) to bifenthrin. Crosses of homozygous, diploid females with hemizygous, haploid males showed that, in the UK strain, METI-acaricide resistance was paternally and maternally inherited, and was an incompletely dominant trait. Another tebufenpyrad-resistant strain from the UK, originating from a chrysanthemum nursery (Chrysanthemum foeniculaceum Giseke; Asteraceae) was collected eight months later at a site c 210 km distant from the first. These are the first published incidences of METI-acaricide resistance in Europe and implications for the future use of these compounds are discussed.     

小菜蛾对丁烯氟虫腈的抗性遗传力及风险评估

采用丁烯氟虫腈对小菜蛾敏感品系进行室内抗性筛选,饲养15代,汰选13代,平均成活率为35.12%,获得抗性品系(R),与敏感品系(S)比较,抗性指数为90.27倍。应用域性状分析法,研究小菜蛾对丁烯氟虫腈的抗性现实遗传力,并对不同杀死率下抗性发展速率进行预测。结果表明,连续筛选前7代(F₀~F₆),小菜蛾对丁烯氟虫腈的抗性现实遗传力为0.2332;不连续筛选后6代(F₇~F₁₄,8代中有2代未筛选),现实遗传力为0.0203。整个13代筛选期间,现实遗传力为0.2206。假设遗传力为室内筛选估算值的一半、死亡率为50%~90%,预计小菜蛾对丁烯氟虫腈抗性增长10倍,需要约22.8~10.3代。