甘肃省二斑叶螨地理种群的遗传分析

为探讨甘肃省二斑叶螨Tetranychus urticae种群遗传多样性及遗传分化,通过mtDNA-COI基因DNA条形码技术对采自甘肃省8个不同生境35个二斑叶螨地理种群的582个样品进行序列分析及地理种群的遗传分化分析。结果表明,获得二斑叶螨mtDNA-COI基因片段大小为424 bp,其中保守序列336个,变异位点66个,简约信息位点45个,单突变位点21个;碱基(A+T)含量明显高于(C+G)含量,有明显的A/T碱性偏倚性;在35个地理种群中共检出16个单倍型,单倍型指数为0.906;Mantel检测结果表明种群间的遗传距离与地理距离无显著相关性;35个地理种群间的遗传分化指数Fst为0.012,种群间变异为1.200。表明二斑叶螨的遗传变异主要来自于种群内部,种群间还未发生明显的遗传分化。     

智利小植绥螨防治大棚草莓二斑叶螨试验初报

二斑叶螨是上海地区温室大棚草莓上的重要害虫之一。研究了释放智利小植绥螨防治大棚草莓上二斑叶螨的效果。结果表明,释放智利小植绥螨对草莓二斑叶螨有显著抑制作用,防治效果十分明显。以300头/m2的释放量释放智利小植绥螨14 d后,防效可达99.66%,比5%噻螨酮EC 2 000倍液处理高33.45百分点,释放量为100头/m214 d后的防效也达到了60.24%。且智利小植绥螨具有较大的探索能力,在释放区将害螨捕食完毕后,能迅速扩散到邻近的有害螨的区域继续捕食。     

京冀地区蔬菜叶螨优势种类鉴定

叶螨是蔬菜作物上的一类重要农业害螨,但其在蔬菜上发生为害的优势种类尚不明确。本研究中,2009-2013年连续5年于北京和河北部分地区定点和非定点采集田间蔬菜作物上的叶螨,采用形态学方法和分子生物学方法进行种类鉴定。结果表明,所采集地的茄果类蔬菜和豆类蔬菜上叶螨种类包括截形叶螨和二斑叶螨,未发现有朱砂叶螨或者其它叶螨种类,表明截形叶螨和二斑叶螨是目前北京和河北部分地区蔬菜作物上的主要叶螨种类,改变了以往文献中朱砂叶螨是常见蔬菜作物主要叶螨种类的传统认识。研究结果将有助于田间蔬菜叶螨的针对性高效防治。     

二斑叶螨与朱砂叶螨种间竞争的研究

１９９７年４～６月对二斑叶螨与朱砂叶螨的种间竞争进行了研究。结果表明,无论单种种群还是混合种群,二斑叶螨的活动虫态和雌成虫的ｒｍ均高于朱砂叶螨。二斑叶螨具有更强的种间竞争能力,在该螨发生地极有可能取代朱砂叶螨而成为农田中的优势种。     

二斑叶螨对阿维菌素的抗药性及抗性基因的PASA检测技术

为了明确二斑叶螨Tetranychus urticae Koch对阿维菌素的抗性水平,采用玻片浸渍法测定了北京4个地区二斑叶螨雌成螨对阿维菌素的抗药性,建立了特异性等位基因PCR（PASA）方法,并检测了二斑叶螨谷氨酸门控氯离子通道（GluCl）基因片段上G323D的突变频率。结果显示,北京昌平、海淀、密云和怀柔4个田间二斑叶螨种群对阿维菌素均达极高抗性水平,其中昌平种群抗性最高,LC₅₀值为448.93 mg/L,抗性倍数为4 988.11倍。室内敏感种群未见抗性个体,昌平和密云种群G323D等位基因突变频率为100.00%,怀柔和海淀种群分别为86.25%和90.00%。北京4个地区二斑叶螨种群对阿维菌素达极高抗性水平,抗性基因的突变频率也很高,表明阿维菌素不适宜用来防治这些地区的二斑叶螨种群。     

二斑叶螨对阿维菌素抗性的CAPS标记

为了实现二斑叶螨Tetranychus urticae Koch对阿维菌素抗药性的快速检测,本研究建立了一种叶螨对阿维菌素抗药性的快速分子检测技术,即酶切扩增多态性序列(cleaved amplified polymorphic sequences,CAPS)标记技术,检测二斑叶螨谷氨酸门控氯离子通道(Glu Cl3)基因片段上G326E的突变频率,并采用琼脂浸叶法测定田间5个种群对阿维菌素的抗药性。结果表明,北京密云、顺义、昌平、浙江宁波和海南吉阳5个种群对阿维菌素的抗性倍数分别达1 155.63、1 317.10、844.19、314.95和1 799.69倍,均为极高抗性水平;CAPS检测发现我国二斑叶螨抗性基因存在G326E位点突变,但在供试的5个不同种群中突变频率变异很大,其中北京昌平种群G326E突变频率高达90.00%,密云和顺义种群均为26.67%,浙江宁波种群为5.00%,而海南吉阳种群不存在该位点的突变。表明该CAPS标记还需与其它抗性机制或检测技术结合来实现叶螨对阿维菌素抗性的早期检测和预警。     

四个二斑叶螨地理种群卵对10种杀螨剂的敏感性差异

为了明确二斑叶螨卵对现有杀螨剂的敏感性现状,采用棉苗浸渍法测定了4个二斑叶螨地理种群卵对10种常用杀螨剂的敏感性。结果表明,昌乐和寿光蔬菜大棚内二斑叶螨卵的敏感性明显低于郑州和沂源种群。其中,4个抗性种群对哒螨灵的敏感性均较低,敏感系数从高到低依次为:昌乐(216.02倍)、郑州(112.45倍)、沂源(53.56倍)、寿光(12.74倍)。唑螨酯和螺螨酯对卵的毒力均较高,是防治二斑叶螨卵较好的药剂。     

二斑叶螨抗甲氰菊酯、四螨嗪、螺虫乙酯、哒螨灵品系的微卫星DNA分析

采用微卫星标记法,对二斑叶螨（Tetranychus urticae Koch）敏感品系（S）和室内筛选的4个抗性品系（抗甲氰菊酯品系、抗四螨嗪品系、抗螺虫乙酯品系、抗哒螨灵品系）进行微卫星DNA多态性分析。结果表明,二斑叶螨4个抗性品系显示出微卫星DNA 多态性。引物Tu11在相似系数0.80处将5个二斑叶螨品系区分开。引物Tu1在相似系数0.70处将5个二斑叶螨品系区分开。微卫星DNA多态性虽不能定位抗性基因,但可结合聚类分析软件,为二斑叶螨对甲氰菊酯、四螨嗪、螺虫乙酯、哒螨灵抗性快速分子检测技术提供依据,指导二斑叶螨田间抗药性监测及抗药性治理。     

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。     

增效浏阳霉素防治叶螨的效果和对智利植绥螨影响的研究

在实验室内用5％增效浏阳霉素乳油1000倍液防治截形叶螨,24小时后的死亡率为95.5％。对三氯杀螨醇有较强抗性的二斑叶螨和朱砂叶螨,48小时后的死亡率也达90％左右。浏阳霉素对3种叶螨均无杀卵作用,但施药5～6天后,对初孵幼螨仍能杀死90％以上。低温能降低浏阳霉素的药效。在温室中施药一周后。对二斑叶螨的雌成螨无残效,但幼螨和前若螨的死亡率可达97.4％。以磷酸兰苯酯作增效剂的浏阳霉素比亚磷酸三苯酯作增效剂的药效好。在同一剂量下,对二斑叶螨的死亡率分别为98.2％和53.4％。5％浏阳霉素的1000倍液对智利植绥螨成螨的生存率、在叶上的定居率及着卵量均无影响。在温室栽培月季上喷药1次防治二斑叶螨,36天后防治效果仍保持在99％,而用三氯杀螨醇和敌敌畏防治,施药一周后需再次防治。     

淡紫拟青霉、厚垣轮枝菌生防菌剂对当归“麻口病”的防治效果

为了明确淡紫拟青霉、厚垣轮枝菌生防菌剂对当归生长量的影响及对麻口病的防治效果,进行了田间药效试验。结果表明,两种生防菌剂在当归移栽时拌细干土穴施对当归生长量(出苗、株高、叶片数、冠幅)有一定的影响;但可有效防治当归麻口病,其中淡紫拟青霉颗粒剂41.25kg/hm2处理组防效最高,为63.43%,与其他处理差异显著(P0.05);各处理对当归有较好的增产作用,增产率为25.78%~63.01%,其中淡紫拟青霉颗粒剂45.00kg/hm2处理增产率最高,为63.01%,其次为厚垣轮枝菌微粒剂33.75kg/hm2处理,增产率为61.67%;菌剂各处理相比对照可明显提高特等归比例。淡紫拟青霉颗粒剂41.25、45.00kg/hm2和厚垣轮枝菌微粒剂33.75kg/hm2穴施可有效防治当归麻口病,提高当归产量,可用于生产上防治当归麻口病。     

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。     

应用智利小植绥螨防治温室一串红上二斑叶螨的试验

1983年12月到1984年4月间在北京中山公园温室盆栽花卉(一串红)上成功地进行了释放智利小植绥螨(Phytoseiulus persimilis A.H.)防治二斑叶螨(Tetranychus urticae Koch)的试验。按益、害螨1:10或1:20的比例分别释放两次。每隔7—10天检查一次,释放后3—4周叶螨数显著下降,以后一直维持在大约每叶1头以下。对照区在叶螨高峰期每叶平均126头。施药区虽经6次农药防治,在高峰期平均每叶叶螨112头。释放区花卉色泽和花朵大小也较对照区和施药区的显著为好。     

Biological control of two-spotted spider mite (Tetranychus urticae) by Phytoseiulus persimilis on strawberries grown in walk-in' plastic tunnels, and a simplified method of spider mite population assessment

During 1980 and 1981, a large-scale trial of the biological control of two-spotted spider mite ( Tetranychus urticae Koch) on protected strawbenies, using the predatory'mite Phytoseiulus persimilis Athias-Henriot, was done in 52 'walk-in' plastic tunnels on a commercial nursery in southern England. Introductions of predatory mites in March or early April at a rate of one per plant were consistently successful. In 1980, when predators had not been introduced the previous year (so enabling large numbers of spider mites to overwinter) peak mite populations were large, causing slight foliar damage in some tunnels before control was achieved. In 1981, only a small residual population of spider mites had survived from the previous year and peak numbers were small; the crop appeared healthy and there was no visible damage by mites. For jdequate control, reintroduction of predators was found to be necessary when CTops were replanted in the summer following soil cultivation and sterilization with methyl bromide.
A population assessment method for two-spotted spider mite based on counting aggregations of the mites was devised. The mean number of spider mites (all stages) per leaf was found to be approximately the same as the number of leaves with five or more mites present in a 25-leaf sample.     

棉叶螨的抗药性现状与治理策略

棉叶螨也称为棉红蜘蛛,属蛛形纲叶螨科,其种类繁多,分布范围广,世代周期短,是为害棉花的一类重要害螨。目前,用于防治棉叶螨的化学药剂主要是神经毒剂及呼吸抑制剂2大类,且棉叶螨对多数药剂产生了不同程度的抗性,以二斑叶螨Tetranychus urticae为首的植食性害螨已成为世界上抗药性最严重的节肢动物之一。美国路易斯安那州棉田二斑叶螨种群对阿维菌素产生了1 415倍抗性,而国内棉花上棉叶螨主要对有机磷类药剂产生了较强抗性,最高为467倍。棉叶螨产生抗药性的机制主要涉及靶标突变及解毒代谢增强,其中靶标突变主要涉及乙酰胆碱酯酶、电压门控钠离子通道和谷氨酸门控氯离子通道等;细胞色素P450单加氧酶、羧酸酯酶和谷胱甘肽S-转移酶等一种或多种解毒酶共同参与害螨对化学药剂的解毒代谢。该文主要从棉叶螨的种类及分布、用于防治棉叶螨的化学药剂、棉叶螨的抗药性现状、抗药性机制解析和抗药性治理策略5个方面进行阐述,提出因地制宜的抗药性治理策略,旨在为棉叶螨的田间防治提供指导。     

西方盲走螨防治苹果树叶螨的研究

通过室内个体饲养观察,明确西方盲走螨捕食山楂叶螨和李始叶螨生长发育情况良好。1983～1985年,兰州田间试验表明:5月下旬到6月中旬,根据苹果树的不同树龄和叶螨的虫口基数,以1:36～64的益、害比,每株释放西方盲走螨雌成螨350～2,750头,经过45～60天,释放树上山楂叶螨和李始叶螨的种群数量发展缓慢,渐趋衰亡,达到完全控制。释放西方盲走螨不仅当年控制李始叶螨为害,可减少用药3～4次;其效果可持续两年。     

Antibiosis of maize inbred lines to the carmine spider mite, tetranychus cinnabarinus

The antibiosis of tenZea mays L. inbred lines to the carmine spider mite,Tetranychus cinnabarinus (Boisduval) (Acari: Tetranychidae), was evaluated. Two maize inbred lines previously reported as resistant to this spider mite and a susceptible inbred line were compared with B96 (formerly called 41:2504B), reported as being resistant to the two-spotted spider mite T. urticae and to the European corn borer (Ostrinia nubilalis Hübner). Other lines were derived from B96. All lines originated in the U.S.A. and were tested in Israel at two different growth stages. Four days after inoculation of detached leaf squares with adult mites, significant differences in susceptibility were observed among lines. At the 3-leaf stage lines B68, B96, B79, A619, B65, B49 and B64 reduced the average mite daily fecundity by 43%, 64%, 66%, 67%, 77%, 81% and 87%, respectively, as compared with the most susceptible line, B52. At the flowering stage, the average reduction in mite daily fecundity was much lower: inbred lines B64, A619 and B96 reduced the average mite daily fecundity by 48%, 51% and 86%, respectively, whereas the seven other genotypes had an intermediate or a susceptible reaction to the carmine spider mite, with A661 being the most susceptible. Our results show that B96 could be used as a source of resistance in developing improved resistance of inbred lines of maize to carmine spider mites.     

The potential of spiders of different taxa and a predacious mite to feed on the carmine spider mite — a laboratory study

Four spider species and the predacious mitePhytoseiulus persimilis (Athias-Henriot) were examined in the laboratory for their capacity to feed on the carmine spider mite,Tetranychus cinnabarinus (Boisduval). The adult females ofChiracanthium mildei L. Koch showed the highest capacity for feeding onT. cinnabarinus (27.5 mites/day) and differed significantly from all other spider species, including the immatureC. mildei which consumed an average of 18.9 mites/day — nearly equal to that of the Oxyopidae species (16.8 mites/day). The salticid (10.1 mites/day) and theridiid (9.5 mites/day) spider species had the lowest capacity, which was nearly equal to that of the predacious miteP. persimilis (11.3 mites/day). Results indicate that spiders play an important role as mite predators.     

Organophosphate insecticides and acaricides antagonise bifenazate toxicity through esterase inhibition in Tetranychus urticae

BACKGROUND: Bifenazate is a carbazate acaricide known for its potency, particularly against tetranychid mite species such as the two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae). It was recently shown that the compound needs to be activated by an S,S,S-tributyl-phosphorotrithioate (DEF)-sensitive mechanism in spider mites to display full acaricidal efficacy. The ability of well-known organophosphates and carbamates to inhibit the activation of bifenazate and thus compromise its acaricidal potential was tested.RESULTS: Esterase activity determined in vivo after pre-exposure of mites with organophosphates and carbamates revealed--depending on the compound--varying esterase inhibition nicely correlated with the ability of the individual compound to antagonise bifenazate action on mites.CONCLUSIONS: The findings illustrate that organophosphates and carbamates interfere with bifenazate efficacy, most probably by inhibiting carboxylesterases responsible for the activation of the pro-drug. As a result of the strong antagonism, mixtures of bifenazate with carbamates or organophosphates should not be used under field conditions. Moreover, there exists a real threat in repeatedly applying organophosphates and bifenazate. The present study again illustrates how important mode of action information is for the proper planning of resistance management strategies.