15种药剂对二斑叶螨防治效果研究

为筛选出防治二斑叶螨的有效药剂,以黄瓜为试验材料,采用苗期接虫及叶面喷雾的方法进行15种常用杀螨剂对二斑叶螨防治效果的研究。结果表明:药后1 d, 43%联苯肼酯悬浮剂3 000倍液、73%克螨特乳油2000倍液、25%三唑锡可湿性粉剂1000倍液的防治效果均达94%,显著优于其他药剂;药后3 d,25%单甲脒水剂1 000倍液的防治效果大幅提高,达95.62%,与43%联苯肼酯悬浮剂3 000倍液、73%克螨特乳油2 000倍液、25%三唑锡可湿性粉剂1 000倍液差异均不显著;药后7 d,200 g/L双甲脒乳油1 000倍液、50%苯丁锡可湿性粉剂2 000倍液、15%哒螨灵乳油2 000倍液、240 g/L螺螨酯悬浮剂2 000倍液防效也随之升高,均达92%,而50 g/L氟虫脲可分散性液剂1 000倍液、1.8%阿维菌素乳油1 000倍液、20%丁氟螨酯悬浮剂1 500倍液、45%毒死蜱乳油1 000倍液、5%噻螨酮乳油1 500倍液、240 g/L螺虫乙酯悬浮剂3 000倍液防治效果则表现较差;药后14 d,73%克螨特乳油2 000倍液、25%三唑锡可湿性粉剂1 000倍液、25%单甲脒水剂1 000倍液、50%苯丁锡可湿性粉剂2 000倍液、240 g/L螺螨酯悬浮剂2 000倍液、43%联苯肼酯悬浮剂3 000倍液均保持很好效果,都在96%以上,建议在田间交替使用43%联苯肼酯悬浮剂3000倍液、73%克螨特乳油2000倍液和25%三唑锡可湿性粉剂1000倍液来防治二斑叶螨。由于99%绿颖矿物油200倍液(防治效果为83.24%～91.18%)无毒无残留,对环境、产品安全,可推荐使用。     

朱砂叶螨对久效磷抗性的遗传分析

采自棉田的朱砂叶螨（Tetranychus cinnabarinus Boisduval）种群使用80-267（×10#+[-6]）的久效磷7次筛选后,抗性水平由42.34上升到161.49倍。以其作为抗性品系（R）,通过和感性品系的杂交和回交研究了朱砂叶螨抗久效磷的遗传方式。正交和反交F#-1代（SR和RS）的lg(LC)-P方程介于S与R之间偏向R方,显性系数D#-（SR）和D#-（RS）分别为0.5634和0.5610,表明抗性是由不完全显性基因控制。F#-1杂合子与亲本的回交表明其后代F#-2（SR×S♂和RS×R♂）的分离符合孟德尔单基因遗传模型。本试验还测定了抗久效磷朱砂叶螨品系对15种常用杀螨剂的敏感性,结果显示敌敌畏、功夫菊脂和甲氰菊酯对其有较强的毒力。1991-1992年监测了河南棉田朱砂叶螨对久效磷的抗性水平,结果表明抗性倍数位于13.03-45.44之间,抗性处于突增阶段。     

Genetic segregation and the detection of spontaneous wheat-alien translocations

Robertsonian translocation between homoeologous chromosomes is one means for introducing alien genes from related species into common wheat. This study was undertaken to determine if selection for normal segregation of an alien trait could be used to identify favourable translocations. Agrotana (an octoploid agrotriticum, probably derived from Thinopyrum ponticum) carries resistance to the wheat curl mite (Eriophyes tulipae Keifer) which is the vector of wheat streak mosaic virus. Agrotana was crossed with the winter durum Michurinka (Triticum turgidum L. em. Bowden), and resistant F₂ plants were backcrossed four times with Norstar winter wheat (T. aestivum L. em. Thell.). During the later stages of backcrossing and selfing, resistant progenies were tested for their segregation ratios; selection was made for high and stable rates of transmission of mite resistance in segregating male gametes and zygotes. The 49 descendant gametes were tested for Mendelian-like inheritance of resistance. Two lines were identified with segregations that approached Mendelian ratios (1:1 male transmission in a testcross, 3:1 in F₂ and 1:2:1 among F₃ families). Contrary to expectations, selection for stable F₂ ratios (3:1) proved more efficient than selection for normal male transmission (1:1) as a means of identifying these stocks. Chromosome painting and PCR (polymerase chain reaction) analysis indicated the recovery of two independent Robertsonian translocations, both of which probably involved the reunion of the short arm of a group 6 chromosome of Thinopyrum ponticum and the long arm of chromosome 6D. In conclusion, selection for Mendelian ratios from among backcross derivatives of an interspecific hybrid was successful in isolating desirable translocations; cytogenetic methods were only used to characterise desirable stocks once these were identified. This revised version was published online in August 2006 with corrections to the Cover Date.     

不同寄主植物对二斑叶螨和朱砂叶螨发育历期和产卵量的影响

在室内25℃恒温条件下，分别采用菜豆（Phaseolus vulgaris Linn．）、茄子（Solanum melongena Linn．）、月季（Rosa chinensis Jacq．）、桃树（Amygdalus penica Linn．）和转Bt基因抗虫棉（transgenic Bt cotton）等5种植物饲养二斑叶螨（Tetranychus urticae Koch）和朱砂叶螨（T.cinnabarinus（Boisduval）），观察它们在这些寄主上的发育情况。结果表明，不同寄主植物上的2种叶螨发育历期及产卵量略有差别，但2种螨都是在桃树上的发育历期最短，在菜豆上的雌成螨5日产卵量均最高。综合发育历期和产卵量两个因素来看，菜豆和桃树为二斑叶螨的最佳寄主；朱砂叶螨在菜豆、茄子和桃树上发育最适合。2种叶螨相比较，适宜的寄主植物略有不同。     

朱砂叶螨生命表和种群动态的研究

试验在植物生长箱内以5种变动温湿度组合模拟郑州地区6—7月份大气温湿度,以棉叶圆盘饲育朱砂叶螨,所得数据组建了朱砂叶螨生命表.在上述温湿度条件下,又对棉苗上的种群动态进行了观察.结果在供试高温低湿条件下,朱砂叶螨增殖最快,内禀增殖率和净生殖率最高,世代平均日数最短.棉田种群动态系统调查结果与室内研究趋势一致.证实高温干旱季节是朱砂叶螨大量增殖和暴发成灾的气候条件,雨水冲刷和高湿环境是种群数量迅速衰退的主要原因.     

苹果园山楂叶螨空间格局的初步研究

本研究采用7种方法,对6组不同虫口密度水平的抽样资料,考察了山楂叶螨雌成螨的树内格局。结果表明,在各密度水平下,山楂叶螨雌成螨在苹果树内的分布格局,均为聚集型。分布的基本成份是疏松的个体群,个体群内的分布是随机的。个体群的大小随种群密度的增加而加大。聚集强度在中等密度(3头/叶)下最高,其次是偏低密度,高密度下最低。     

北方常见农业土地利用方式对土壤螨群落结构的影响

土壤螨群落与土壤健康状况密切相关,农业土地利用方式会影响土壤螨的生存环境,进而影响螨的群落分布。在北方传统农业区研究了小麦玉米常规轮作农田,1年温室蔬菜大棚、4年温室蔬菜大棚和4年露天菜地下土壤主要理化指标和螨群落结构。研究结果表明露天菜地和温室大棚的利用方式均会提高土壤碱解氮和有机质含量,同时温室大棚的长期利用会增加土壤有效磷含量。螨群落分析显示常规农田中甲螨亚目为优势类群;常规农田转变为温室大棚后,由于施肥造成土壤营养物质含量增加,以及人类对土壤扰动程度的提高,无气门亚目取代甲螨亚目成为温室内螨优势类群。但随着温室年限的延长,螨多样性和粉螨科丰度都要有所下降,这可能是磷累积和强扰动效应的共同后果。常规农田转变为露天菜地后,加强的人类扰动也会降低甲螨亚目丰度,但与温室螨群落相比,4个亚目分布要相对均匀。温室在3种土地利用类型中对土壤螨的负面影响最为明显,从土壤功能的自我维持和修复方面来讲是十分不利的,温室内土壤生物多样性的保护尤其值得人们关注和重视。     

First record of the invasive mite<Emphasis Type="Italic">Tetranychus evansi</Emphasis> in Greece

The red spider miteTetranychus evansi (Acari: Tetranychidae) Baker and Pritchard was recorded for the first time in Greece, in the area of Tympaki (south-central Crete) onSolanum nigrum. T. evansi is a pest of crops of the family Solanaceae, which are grown extensively in Crete. The species identification was based on both morphological and molecular data. The second internal transcribed spacer was PCR amplified and sequenced in samples from Crete. Sequences were compared with the sequence ofT. evansi from Brazil and with the ITS2 sequences (retrieved from GenBank) of the two closely related tetranychid species most commonly found in Greece,Tetranychus turkestan andTetranychus urticae.     

溴氰菊酯对育肥牛痒螨的疗效观察

以０．０３％溴氰菊酯药液对平遥牛场３０２头不同程度患有以背腰部脱毛、皮肤结痂、搔痒为特征的疥螨病牛进行了喷雾杀虫，隔周一次，连用三次，停药一周后被毛重新长出，皮肤恢复弹性，虫检阴性。治疗结果表明，用０．０３％溴氰菊酯治疗牛螨病，疗效可靠，治愈率达１００％，毒性小，复发率低，是一种治疗牛螨病既经济又有效的理想药物     

Resistance in Cucumis sativus L. to Tetranychus urticae Koch. 1. The role of plant breeding in integrated control

Summary The role of plant breeding and particularly of host plant resistance in integrated control is discussed. Host plant resistance to insects and mites, especially to Tetranychus urticae is reviewed. A standard terminology for disease and pest resistance is recommended.