三种主要天敌对二斑叶螨(Tetranychus urticae Koch)的控制作用研究

在实验室条件下,研究了二斑叶螨(Tetranychus urticaeKoch)的3种主要天敌小十三星瓢虫(Adonia var-iegata)、草间小黑蛛(Erigonidium graminicolum)和中华草蛉(Chrysoperia sinica)的成、幼虫对二斑叶螨不同密度的控制作用.在一定的猎物密度范围内,捕食量随着猎物密度的增加而增加,分别用Holling的圆盘方程拟合,经卡方检验,其实测值和理论值均无显著差异.3种天敌各自在不同情况下对二斑叶螨的控制作用,表明其具有重要的保护利用价值.

Acaricidal activity of different extracts from Syzygium cumini L.Skeels(Pomposia) against Tetranychus urticae Koch

Objective:To investigate the acaricidal activity of different extracts from Syzygium cumini(S.cumini)(Pomposia)againsst Tetranyckus urticae Koch(71 urticae)and the biochemical changes in antioxidants enzymes.Methods:Six extracts of S.cumini(Pomposia)at concentrations of 75,150 and 300μg/mL were used to control T.urticae(Koch).Results:The ethanol extract showed the most efficient acaricidal activity agent against T.urticae(98.5%)followed by hexane extract(94.0%),ether and ethyl acetate extract(90.0%).The LC_(50)values of the promising extract-were 85.0,101.0,102.0 and 98.0μ/mL,respectively.The activities of enzymes including ascorbate peroxidase(APX),peroxidase(POD),superoxide dismutase(SOD)and catalase(CAT)in susceptible mites were increased.The activities of all antioxidant enzymes reach the maximum value in mites at LC_(50)with ethanol and ethyl acetate extracts,respectively.Conclusions:The extract of S.cumini has acaricidal acivity against T.urticae,and the ethanol extract is the most efficient.

Research Overview on Occurrence and Control of Tetranychus urticae Koch in China

Tetranychus urticae Koch;Insecticide resistance;Chemical control This paper elaborates the occurrence factors and damage characteristics of Tetranychus urticae Koch in China,and emphatically summarizes three main control strategies of T.urticae,namely agricultural control,chemical control and biological control,as well as research progress in its resistance mechanisms.The problems existing in controlling T.urticae and its resistance management strategies are put forward,to provide a theoretical basis for the resistance management and comprehensive control of T.urticae.

Occurrence and Control of Tetranychus truncatus and T. urticae on Corns of Yanbian Area

The situation of occurrence and hazards by Tetranychus truncatus and T. urticae on corns in test garden of Agricultural College of Yanbian University were narrated in detail. The characteristics of distribution and damage by T. truncates and T. urticae, morphological characteristics, the rule of currencies and its relation- ship with environment were summarized, and the methods of comprehensive treat- ment were put out, which could effectively control the hazard degree of T. truncates and T. urticae on corns.

The Effect of Lion’s Ear (<i>Leonotis nepetifolia</i>) and African Basil (<i>Ocimum gratissimum</i>) Plant Extracts on Two-Spotted Spider Mites (<i>Tetranychus urticae</i>) for Improved Yield and Quality of French Beans

An experiment to evaluate the bio-control potential of Leonotis nepetifolia and Ocimum gratissimum plant extracts against two-spotted spider mites on French beans was conducted in the field. Five plant extract concentrations (1.5%, 3.0%, 6.0% and 12.0% w/v) were applied with water and Abamectin 0.6 ml/L as controls. Mite counts were done before and after treatment application and expressed as corrected percent efficacy. The impact of the mites on the French beans was evaluated by recording percent leaf reduction and quality and quantity by number of pods, pod length, diameter and yield. There was a dose dependent response in percent mite and leaf reduction, number of pods and yield. Treatments applied at 12% w/v indicated higher mite reduction (82.75%) for L. nepetifolia and 69.06% for O. gratissimum compared to abamectin (65.76%). The lowest percent leaf reduction of 1.71% for L. nepetifolia 0.39% for O. gratissimum and abamectin (20.46%) was also at 12% w/v. Similarly, the highest number of pod (61.00) for L. nepetifolia, 48.67 for O. gratissimum compared to 28.33 abamectin and yield (0.88 kg) for L. nepetifolia and 0.90 kg for O. gratissimum was also recorded at 12% w/v compared to 0.36 kg for abamectin. There were no significant differences in pod diameter and pod length between the extracts concentrations and abamectin. The study demonstrated the efficacy of L. nepetifolia and O. gratissimum in managing two-spotted spider mite and subsequent increase in French bean yield under field conditions.

Temperature-dependent development of Neoseiulus barked （Acari： Phytoseiidae） on Tetranychus urticae （Acari： Tetranychidae） at seven constant temperatures

The effect of seven constant temperatures of 15, 20, 25, 27, 30, 35 and 37℃ on developmental time ofNeoseiulus barkeri Hughes were determined in laboratory conditions under 65% - 5% RH and a photoperiod of 12 ： 12 （L ： D） h on nymphal stages of Tetranychus urticae Koch. Total developmental time of females （from egg to adult emergence） at the above-mentioned temperatures was 26.59, 14.43, 6.32, 5.64, 4.59, 3.98 and 4.67 days, respectively. Developmental rate of the N. barkeri increased as temperature increased from 15 to 35℃, but declined at 37℃. A linear and two nonlinear models were fitted to developmental rate of immature stages ofN. barkeri to predict the developmental rate as a function of temperature, as well as to estimate the thermal constant （K） and critical temperatures （i.e., Tmin, Topt and Tmax）. The estimated values of the Tmin and K for total developmental time using the linear model were 12.07℃ and 86.20 degree-days （DD）, respectively. The Trnin and Tmax estimated by the Sharpe-Schoolfield-Ikemoto （SSI） model were 11.90℃ and 37.41℃, respectively. The estimated Topt for overall immature stage development ofN. barkeri by the Lactin and SSI models were 33.89℃ and 24.51℃, respectively. Based on the biological criteria of model evaluation, the linear and SSI models were found to be the best models for describing the developmental rate of overall immature stages of N. barkeri and estimating the temperature thresholds.

Toxicity, inheritance and biochemistry of clofentezine resistance in Tetranychus urticae

This study evaluates the toxicological and biochemical response of two-spotted spider mites to clofentezine selection pressure. The mortality rate of Tetranychus urticae in adult females depends on increased clofentezine concentration and clofentezine was found to be effective against females. The resistance rate of the CUM strain selected 12 times once per generation with clofentezine was increased from 1.28- to 105.27-fold. The interaction of some synergists with clofentezine was analyzed in the clofentezine-resistant CLOF 12 strain. Synergists had no effect on clofentezine toxicity. The clofentezine-resistant CLOF 12 strain showed resistance against chlorpyrifos, abamectin, propargite, fenpyroximate and amitraz. The modes of inheritance of resistance to clofentezine were found to be incompletely dominant and not sex-linked. Esterase enzyme activity was detected both by gel electrophoresis and microplate reader methods, while glutathione S-transferase （GST） and monooxygenase （P450） activity were detected only by the microplate reader method. During the selection period the esterase, the GST and the P450 enzymes activities were raised from 7.69, 7.09 and 0.003 3 to 18.40, 13.11 and 0.003 7 milli-optical density/rain/rag proteins, respectively. An increase was observed in the band intensity of esterases and esterase enzymes may play a role in clofentezine resistance in T. urticae.

联苯肼酯亚致死质量浓度对二斑叶螨Tetranychus urticae解毒酶系的影响

为明确联苯肼酯对二斑叶螨Tetranychus urticae体内解毒酶系的影响,采用叶片浸渍法测定联苯肼酯对二斑叶螨的亚致死质量浓度LC10和LC30,用这2种浓度分别处理二斑叶螨,并测定60 h内二斑叶螨体内谷胱甘肽S-转移酶(glutathione S-transferase,GST)、羧酸酯酶(carboxylesterase,CarE)和多功能氧化酶(multifunctional oxidase,MFO)的比活力,以及米氏常数Km及最大反应速率vmax的变化。结果显示,经LC10和LC30剂量处理二斑叶螨后,其体内CarE、GST和MFO的活性在6~60 h均受到明显诱导。其中,GST和MFO的比活力在12 h最大,分别为对照的1.25倍、1.60倍和1.63倍、1.84倍,CarE的比活力在48 h最大,为对照的1.27倍和1.37倍;与对照组相比,CarE的Km显著减小,vmax显著升高,而GST和MFO的Km显著增大,vmax显著减小。表明3种酶均参与了二斑叶螨对联苯肼酯的解毒代谢,其中CarE与底物的亲和力最大,反应速率最快,其对联苯肼酯的解毒代谢起主导作用。

Frequencies and mechanisms of pesticide resistance in Tetranychus urticae field populations in China

The two-spotted spider mite Tetranychus urticate is an important agricultural pest worldwide.It is extremely polyphagous and has developed resistance to many pesticides.Here,we assessed the pesticide resistance of seven field populations of T.urticae in China,their target site mutations and the activities of their detoxification enzymes.The results showed that abamectin and the traditional pesticides pyridaben,profenofos and bifenthrin had higher resistance or lower toxicity than more recently developed pesticides including chlorfenapyr,spinetoram,cyflumetofen,cyenopyrafen,bifenazate and B-azolemiteacrylic.The frequency of point mutations related to abamectin resistance,G314D in the glutamate-gated chloride channel 1(GluCl1)and G326E in GluC13,ranged 47%-70%and 0%-97%,respectively.The frequency of point mutations in A1215D and F1538I of the voltage-gated sodium channel gene(VGSC),which may increase resistance to pyrethroids,ranged 88%-100%and 10%-100%,respectively.For target sites related to organophosphate resistance,mutation frequencies ranged 25%-92%for G119S and 0%-23%for A201S in the acetycholinesterase gene(Ace).Mutation G126S in the bifenazate resistance-related cytochrome b gene(Cytb)was observed in three of the seven T.urticae populations.Higher activities of detoxification enzymes(P450,GST,CarEs and UGTs)were observed in two T.urticae populations,with significant difference in the XY-SX population.These results provide useful information on the status of pesticide resistance of T.urticae in China and suggest that T.urticae field populations may have multiple resistance mechanisms.

Divergent methylation pattern in adult stage between two forms of Tetranychus urticae （Acari： Tetranychidae）

The two-spotted spider mite, Tetranychus urticae Koch has two forms： green form and red form. Understanding the molecular basis of how these two forms established without divergent genetic background is an intriguing area. As a well-known epigenetic process, DNA methylation has particularly important roles in gene regulation and developmental variation across diverse organisms that do not alter genetic background. Here, to investigate whether DNA methylation could be associated with different phenotypic conse- quences in the two forms of T. urticae, we surveyed the genome-wide cytosine methylation status and expression level of DNA methyltransferase 3 （Tudnmt3） throughout their entire life cycle. Methylation-sensitive amplification polymorphism （MSAP） analyses of 585 loci revealed variable methylation patterns in the different developmental stages. In particular, principal coordinates analysis （PCoA） indicates a significant epigenetic differentiation be- tween female adults of the two forms. The gene expression of Tudnmt3 was detected in all examined developmental stages, which was significantly different in the adult stage of the two forms. Together, our results reveal the epigenetic distance between the two forms of T. urticae, suggesting that DNA methylation might be implicated in different developmental demands, and contribute to different phenotypes in the adult stage of these two forms.

腈吡螨酯对扁豆二斑叶螨的田间药效及安全性评价

二斑叶螨是扁豆主要害虫之一,发生较重时可降低扁豆产量和品质。本研究评价了30%腈吡螨酯悬浮剂对扁豆二斑叶螨的田间药效及其对扁豆的安全性。田间使用有效成分量67.5、90、112.5 g/hm2,药后1 d三地的田间防效66.5%~85.9%、药后3 d 82.1%~92.3%、药后7 d 86.9%~95.2%、药后14 d 80.9%~96.1%,能有效防控扁豆二斑叶螨,具有较好的速效性和良好的持效性。作物安全性试验表明30%腈吡螨酯悬浮剂对扁豆安全。建议登记30%腈吡螨酯悬浮剂防治扁豆二斑叶螨,推荐使用有效成分量67.5~112.5 g/hm^(2)(制剂量15~25 mL/667m^(2)),于二斑叶螨发生初期施药1次。

巴氏新小绥螨高效氯氟氰菊酯抗、敏品系对二斑叶螨捕食功能的研究

【目的】明确巴氏新小绥螨(Neoseiulus barkeri)高效氯氟氰菊酯抗、敏性品系对二斑叶螨(Tetranychus urticae)的捕食功能,探究防治潜力。【方法】在实验室条件下以观察小室法测定巴氏新小绥螨高效氯氟氰菊酯抗、敏品系雌成螨对二斑叶螨3个发育阶段(卵、若螨、成螨)的捕食功能及搜寻效应。【结果】巴氏新小绥螨高效氯氟氰菊酯抗、敏品系对二斑叶螨的捕食功能类型均为Holling-Ⅱ型,且对二斑叶螨卵、若螨和成螨的捕食量变化趋势相同,均随着猎物密度增长而增加,捕食量达到最大后趋于平衡。巴氏新小绥螨抗性品系对二斑叶螨卵和成螨的处理时间分别为0.0177 d和0.0269 d,均短于敏感品系(0.0188 d和0.0295 d);攻击速率分别为2.2536和1.1586,均快于敏感品系(2.3029和1.6292)。巴氏新小绥螨抗高效氯氟氰菊酯品系对二斑叶螨卵和成螨的捕食能力(a/T_(h))和搜寻效应较敏感品系更优。【结论】巴氏新小绥螨高效氯氟氰菊酯抗药性品系对二斑叶螨卵和成螨有非常好的捕食能力,可与减量化学药剂共同应用于田间防治二斑叶螨。

不同药剂对二斑叶螨和截形叶螨的田间防效研究

为测定不同药剂对二斑叶螨和截形叶螨的防治效果,选择12种不同类型药剂对两种叶螨进行田间防效试验。结果表明,药后3 d不同药剂对二斑叶螨的防效差异很大,0.5%依维菌素乳油、43%联苯肼酯悬浮剂、30%腈吡螨酯悬浮剂、20%丁氟螨酯悬浮剂的防效均超过90%,而1.8%阿维菌素乳油的防效最低,为58.17%;除依维菌素外,其他药剂对截形叶螨的防效均超过90%。药后7 d不同药剂对二斑叶螨的防效处于40.30%~97.70%,对截形叶螨的防效处于87.55%~99.45%,说明12种药剂在药后3 d和7 d对截形叶螨的防效均高于对二斑叶螨的防效。综合不同时间点的防效结果,12种药剂均可用于防治截形叶螨,依维菌素、联苯肼酯、丁氟螨酯、30%乙唑螨腈悬浮剂及复配剂45%联苯肼酯·乙螨唑悬浮剂可轮换使用防治二斑叶螨。

77种植物提取物杀虫活性初步研究

为评价39科77种植物的杀虫活性,本研究采用叶碟喷雾法、浸渍法和喷雾法,分别测定了植物乙醇提取物对二斑叶螨、西花蓟马和麦长管蚜的杀虫活性,进一步测定了杀虫活性较高的植物对二斑叶螨、西花蓟马和麦长管蚜的室内毒力。结果表明:在1 g/m L的供试剂量下,颠茄、蟛蜞菊、咽喉草、菝葜、沙棘、石竹、凌霄花、山佩兰8种植物对二斑叶螨的72 h校正死亡率较高,均在70%以上;LC_(50)分别为254、297、413、424、428、553、663、725 mg/m L;颠茄、蟛蜞菊对西花蓟马的72 h校正死亡率均在80%以上,其LC_(50)分别是272、306 mg/m L;菝葜、咽喉草、沙棘、羊角蒿、凌霄花和山佩兰对西花蓟马72 h的校正死亡率在70%~80%,其LC_(50)分别为446、485、523、563、710、712 mg/m L;虎杖、颠茄、牛叠肚、地肤子、狼毒5种植物对麦长管蚜72 h的校正死亡率在70%以上,其LC_(50)分别为281、336、540、657、730 mg/m L。因此,颠茄、虎杖、蟛蜞菊、菝葜等植物对不同供试昆虫的校正死亡率均较高,表现出良好的杀虫活性,值得进一步研究。

草莓二斑叶螨外部形态的扫描电镜观察

【目的】为深入了解草莓二斑叶螨(Tetranychus urticae Koch)各发育阶段的外部形态和超微结构特征,为草莓害螨的生物学研究和科学防控提供参考。【方法】以草莓植株培养获得不同发育阶段的二斑叶螨个体样本,采用扫描电镜观察各生育阶段的外部形态和超微结构。【结果】草莓二斑叶螨卵为圆形;幼螨足3对,有肛毛无生殖毛,生殖区完全不可见;若螨4对足,第Ⅰ若螨无生殖毛,腹面肛区末端肤纹纵向,背毛c1之间出现肤纹突;第Ⅱ若螨出现生殖区痕迹和1对生殖毛,sc1至c1之间出现肤纹突;雌成螨呈椭圆形,腹毛3a至4a、4a至ag两侧发现肤纹突;雄成螨呈卵圆形,背腹表皮肤纹大致为横向,无肤纹突。

不同药剂对梨树二斑叶螨的田间防治效果评价

为筛选适用于防治梨园二斑叶螨的药剂,开展田间药效试验。结果表明:药后3 d,各药剂处理的防治效果为63.93%~74.59%,药后7 d防治效果为71.55%~83.04%,药后14 d防治效果为75.97%~86.80%,前期整体防治效果不高,后期防治效果有所上升。其中,20%丁氟螨酯悬浮剂+43%联苯肼酯悬浮剂处理14 d后的防治效果最高,可达86.80%,其次是43%联苯肼酯悬浮剂和22%阿维菌素·螺螨酯悬浮剂,14 d后的防治效果分别为85.84%和83.05%。以上3种农药可以在当地梨树上推广应用,不推荐施用20%丁氟螨酯单剂。

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 2 6.5 6、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。

北京地区二斑叶螨不同种群的药剂敏感性

【目的】明确北京地区作物上二斑叶螨(Tetranychus urticae Koch)不同种群对杀螨剂的敏感性水平,了解二斑叶螨对药剂敏感性与体内4种解毒酶活力的相关性。【方法】在实验室内采用改进的玻片浸渍法(slide-dip method)检测北京房山、怀柔、昌平、延庆和平谷5个地区二斑叶螨田间种群对联苯肼酯、阿维菌素、螺螨酯和哒螨灵4种杀螨剂的敏感性;采用PCR技术对单头叶螨的CYTB基因进行扩增和测序,检测二斑叶螨对联苯肼酯的抗性突变位点;并采用酶标仪微量板法,检测二斑叶螨体内与抗性相关的多功能氧化酶、乙酰胆碱酯酶、羧酸酯酶和谷胱甘肽S-转移酶的活力。【结果】5个田间种群对联苯肼酯最敏感,其LC50分别为2.4880、6.4693、6.2398、0.7882和14.7783 mg·L-1。对阿维菌素的敏感性次之,其LC50分别为22.4712、35.4431、14.5260、15.4904和14.0023 mg·L-1。对螺螨酯和哒螨灵的敏感性非常低,螺螨酯的LC50分别为49.6833、81.8826、72.9609、204.4609和1 433.5137 mg·L-1,哒螨灵的LC50分别为202.6902、806.8324、375.3518、188.3234和2 310.9040 mg·L-1。延庆地区二斑叶螨乙酰胆碱酯酶、羧酸酯酶和谷胱甘肽S-转移酶的活性显著高于其他地区,其活力分别为14.9508U/(mg protein)、0.2271μmol·mg-1 protein·30 min-1和58.2962 U/(mg protein)。怀柔地区多功能氧化酶的活性显著低于其他地区,其活力为1.4272μmol·mg-1 protein·30 min-1。联苯肼酯、阿维菌素、螺螨酯和哒螨灵的敏感性水平与乙酰胆碱酯酶、羧酸酯酶、谷胱甘肽S-转移酶和多功能氧化酶的酶活力之间没有直接的线性关系;采用PCR技术对5个地区的288个二斑叶螨个体进行CYTB基因检测后,仅发现怀柔地区的一个个体CYTB基因第126位氨基酸密码子的第一位核苷酸由G突变为A导致氨基酸由G突变为S,其余地区均无突变,这与生物测定方法中各地区对联苯肼酯较敏感的结果基本一致。【结论】北京地区二斑叶螨不同种群对联苯肼酯敏感性最高,对阿维菌素的敏感性次之,对螺螨酯和哒螨灵敏感性非常低;二斑叶螨对4种杀螨剂的敏感性水平与乙酰胆碱酯酶、羧酸酯酶、谷胱甘肽S-转移酶和多功能氧化酶的酶活力之间没有直接的线性关系;通过检测到的基因突变个体,说明怀柔地区二斑叶螨种群中存在着对联苯肼酯产生高抗性风险的个体。PCR方法能够更加快速准确地检测种群抗性发展程度。基于以上结果,在农业防治二斑叶螨中应降低联苯肼酯使用频率,交替使用阿维菌素,避免使用螺螨酯,停止使用哒螨灵,以延缓和降低二斑叶螨产生抗性的风险。

二斑叶螨抗四螨嗪品系筛选及其解毒酶活力变化

【目的】筛选二斑叶螨对四螨嗪的抗性,并明确其解毒酶的变化。【方法】采用室内生物测定和生化分析方法,研究二斑叶螨对四螨嗪的抗性发展趋势及其解毒酶活力变化。【结果】室内用四螨嗪筛选二斑叶螨21代(Clo-R21品系),抗性倍数(RR)为122.26;Clo-R21品系对哒螨.四螨嗪和浏阳霉素具有较高的交互抗性,RR分别为21.80和10.66;对阿维菌素、甲氰菊酯、三氯氟氰菊酯、氯氰菊酯、三唑锡和苦皮藤生物碱具有低水平的交互抗性,RR分别为6.85、5.45、5.02、3.88、3.48、1.68;对苯丁锡、唑螨酯、噻螨酮具有负交互抗性,RR分别为0.72、0.65、0.55;增效剂磷酸三苯酯(TPP)、顺丁烯二酸二乙酯(DEM)、胡椒基丁醚(PBO)、增效磷(SV1)对抗Clo-R21品系的增效比值分别为1.39、1.70、6.78、1.64;Clo-R21品系体内羧酸酯酶(CarE)、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)分别是敏感品系的2.25、2.04、1.91、1.98和26.68倍。【结论】二斑叶螨对四螨嗪的抗性主要受MFO介导,而CarE、ACP、ALP和GSTs也参与四螨嗪抗性的形成。

地肤提取物杀螨活性的研究

采用多种溶剂和方法对地肤全株进行了提取,测定了其中杀螨活性最高的氯仿提取物的多种溶剂萃取物对二斑叶螨(Tetranychus urticae Koch)和朱砂叶螨[Tetranychus cinnabarinus(Boisduval)]的生物活性。结果表明,氯仿提取物的生物活性显著高于石油醚和甲醇提取物,提取物的氯仿萃取物对2种螨的生物活性最强。本试验还对该种植物的杀螨活性有效成分进行了初步研究。氯仿萃取物经柱层分离得到流分112个,经薄层层析(TLC)检验后,相同成分者合并,最终得流分11个。生物活性测定结果表明,F9活性最高,其对二斑叶螨、朱砂叶螨和山楂叶螨的致死中浓度分别达到了0.390 3、0.298 1、0.256 8 mg /mL。