苹果园混合覆盖植物对害螨和东亚小花蝽的影响

苹果园种植紫花苜蓿，为捕食性天敌提供了适宜的生存环境和补充猎物，使苹果园天敌数量增加，叶螨种群下降。夏至草是苹果园杂草的优势种，该杂草可提供天敌生存所需的花粉，花蜜和猎物，使东亚小花蝽发生时间提早，发育速度加快。在６月中旬关，东亚小花蝽可在夏至草上完成２，在紫花苜蓿丰完成１代。夏至草与紫花苜蓿的比例变化影响苹果无节肢支物种数，当混合植被中夏至草的覆盖度大于２５％时，对覆盖植物和苹果树冠捕食性天敌种     

生草园捕食性天敌东亚小花蝽的人工操纵技术

在北京巨山农场果园中，分别在６月初和６月中旬，刈割苹果树行间的紫花苜蓿并将其放在树冠下后，东亚小花蝽既向割草区周围的紫花苜蓿上扩散，也向割草区苹果树上迁移。割草后３天，割草区周围紫花苜蓿上小花蝽数量增加２０％～１１９％，其增加量随距割草区距离的增加而减少，割草区苹果树冠上小花蝽数量比割草前增加２～３倍，蝽螨比可提高１４倍，树冠小花蝽增加的数量受小花蝽扩散能力和割草时间的影响。试验结果表明，适时刈割苹果园中的紫花苜蓿，对控制害螨有明显的作用     

东亚小花蝽的发生和扩散与苹果园和邻近农田植被的关系

１９９２～１９９５年于北京对主要天敌东亚小花蝽在植被多样化苹果园与邻近菜地、玉米田等生境之间繁殖扩散的互作关系进行了研究。结果表明５月上旬至６月中旬,东亚小花蝽主要在果园内夏至草和覆盖作物紫花苜蓿及苹果树冠之间互迁繁衍;６月中、下旬,由于园内生境的改变,大量东亚小花蝽飞离果园,迁入邻近菜地和玉米田内建立种群;至９月下旬,进入滞育状态的东亚小花蝽雌成虫回迁至园边夏至草上越冬。研究指出果园植被多样化,有利于东亚小花蝽的发生和增殖,从而更好地发挥天敌控制害虫的作用。     

东亚小花蝽对西花蓟马、二斑叶螨和桃蚜的捕食能力及捕食选择性研究

室内研究了东亚小花蝽对西花蓟马、二斑叶螨和桃蚜的捕食能力及在3种害虫共存条件下的捕食选择性。试验结果表明,东亚小花蝽对西花蓟马、二斑叶螨和桃蚜均具有捕食能力。捕食能力最初随着猎物数量的增加而增加,当猎物数量不断增加时,其捕食量趋于恒定值。在猎物数量充足时,东亚小花蝽对于二斑叶螨、蚜虫和蓟马的日均捕食量分别为17、12.5头和12头。3种猎物共存时,东亚小花蝽对西方花蓟马的捕食选择性均强于对二斑叶螨和桃蚜。选择性依次为西方花蓟马桃蚜≈二斑叶螨。猎物数量相同时取食西花蓟马的数量为12.6头,二斑叶螨和桃蚜的数量分别1.2头和2.4头。     

苏云金素对东亚小花蝽捕食作用的影响

采用二次回归最优设计，研究苏云金素对东亚小花蝽捕食作用的影响，得出日均捕食量（ｙ）与猎物（ｘ１）和捕食者（ｘ２）之间互作关系模型。处理捕食数量回归方程：ｙ＝－０．００２１ｘ２１＋１．２１１２ｘ２２＋０．８８２２ｘ１－１０．３４６５ｘ２－０．０６４９ｘ１ｘ２＋１．７１７４；对照捕食数量回归方程：ｙ＝－０．００１７ｘ２１＋０．７７３４ｘ２２＋０．６９４１ｘ１－６．４９１４ｘ２－０．０４７４ｘ１ｘ２－０．４６３６。综合定性分析和定量分析结果，苏云金素处理东亚小花蝽若虫，减弱了其对二斑叶螨卵的捕食能力，但二者的差异不显著，对种群变化影响不明显     

营养和环境因子对东亚小花蝽生殖的影响

本文研究北京苹果园三种杂草,蚜虫及环境因子对东亚小花蝽生殖的影响。结果表明,越冬代东亚小花蝽在苹果园３月下旬卵巢开始发育,４月初卵巢成熟,并开始产卵。夏至草（Ｌａｇｏｐｓｉｓｓｕｐｉｎａ）甘野菊（Ｄｅｎｄｒａｎｔｈｅｒｎａｂｏｒｅｄｌｅ）和泥胡菜（Ｈｅｍｉｓｔｅｐｔａｌｙｒａｔａ）是东亚小花蝽越冬和早春繁衍的主要场所。室内饲养的小花蝽在３种无蚜虫感染的杂草上均能产卵,但产卵量极低,在带有蚜虫的３种     

两种猎物饲养对东亚小花蝽捕食作用的影响

本文研究了用两种猎物（豆蚜Aphis craccivora、西花蓟马Frankliniella occidentalis）饲养后的东亚小花蝽Orius sauteri成虫对单一猎物的捕食作用及对混合猎物的选择性。结果表明：用不同猎物饲养后的东亚小花蝽成虫对单一猎物的捕食量都随着猎物密度的增加而增大。东亚小花蝽对饲料的选择性研究发现：猎物密度设置为5、10、15、20、25、30头.皿-1,用西花蓟马饲养3代的东亚小花蝽对西花蓟马和豆蚜的捕食量分别是4.80、8.80、11.40、16.00、20.20、20.60头和3.00、4.60、6.40、10.20、15.80、16.20头,两者之间存在显著性差异,倾向于选择西花蓟马;用豆蚜饲养3代的东亚小花蝽对西花蓟马和豆蚜的捕食量分别是4.00、5.80、8.00、11.80、14.80、16.20头和4.80、6.80、12.00、15.20、18.80、19.20头,两者之间存在显著性差异,倾向于选择豆蚜。本结果说明东亚小花蝽对长期取食的猎物已产生了适应性。     

营养和生态因子对东亚小花蝽生长发育的影响

本文研究了果园中几种植物及其上的蚜虫、温度和光周期对东亚小花蝽生长发育的影响。结果表明，在苹果园中，东亚小花蝽捕食多种植物上的蚜虫，同时也从这些植物的花粉、花蜜及汁液中汲取营养。其中夏至草最有利于该虫的生长发育。在２０～２８℃范围内，随着温度的升高，东亚小花蝽的发育速率加快，发育历期缩短。长光周期能明显缩短东亚小花蝽的发育历期。在同一光周期中，该虫雄性个体的发育速率略快于雌性，尤其以接近１３小时光照处理最为明显。     

东亚小花蝽对草地贪夜蛾1龄幼虫的捕食作用

为明确天敌昆虫东亚小花蝽Orius sauteri对草地贪夜蛾Spodoptera frugiperda幼虫的捕食潜力,在室内测定东亚小花蝽5龄若虫和成虫对草地贪夜蛾1龄幼虫的日捕食量,并对其捕食功能、搜寻效应和干扰效应进行分析。结果表明:东亚小花蝽5龄若虫和成虫对草地贪夜蛾1龄幼虫的捕食功能反应符合Holling II模型;东亚小花蝽5龄若虫对草地贪夜蛾1龄幼虫的日最大捕食量、瞬时攻击率和处理单头猎物的时间分别为20.833头、0.747和0.048 d;东亚小花蝽成虫对草地贪夜蛾1龄幼虫的日最大捕食量、瞬时攻击率和处理单头猎物的时间分别为11.236头、1.355和0.089 d。东亚小花蝽的日捕食量与草地贪夜蛾密度呈正相关,搜寻效应与草地贪夜蛾密度呈负相关。东亚小花蝽自身密度对其捕食作用的干扰符合Hassell模型,对草地贪夜蛾1龄幼虫的捕食作用率随自身密度的增加而降低。     

花生-玉米间作种植模式对蓟马类害虫的控制效果

为明确花生-玉米间作种植模式对蓟马类害虫的控制效果,通过3年田间试验系统调查花生单作、玉米单作和花生-玉米间作3种种植模式下蓟马及其主要捕食性天敌东亚小花蝽Orius sauteri的种群数量动态特征及不同种植模式下东亚小花蝽和蓟马的益害比。结果显示,花生-玉米间作种植模式下东亚小花蝽种群密度显著高于花生单作种植模式,花生-玉米间作种植模式下82.94%以上的东亚小花蝽来源于玉米斑块;与2种单作种植模式相比,花生-玉米间作种植模式未显著减少蓟马的种群密度;东亚小花蝽种群密度与蓟马种群密度呈显著线性关系;花生-玉米间作种植模式下东亚小花蝽与蓟马的益害比均显著低于其他2种单作种植模式。表明花生-玉米间作种植模式在局域农田小范围空间尺度下能显著提高捕食性天敌的种群密度,但并不能显著减少蓟马类害虫种群数量。     

苹果园种植覆盖作物对于树上捕食性天敌群落的影响

在苹果园果树行间种植覆盖作物——白花草木樨Melilotus albus Desr.是果园土壤管理制度中的一项措施。它影响到苹果树上捕食性天敌群落的组成。种植覆盖作物后,一些天敌,如拟长毛钝绥螨Amblyseius pseudolongispinosus Xin et Lian和中华草蛉Chrysopa sinica Tjeder等在苹果树上捕食性天敌群落中的个体数量相对百分比有所增加;而另一些,如小花蝽Orius minutus(Linnaeus)、塔六点蓟马Scolothrips takahashii Priesaer和瓢虫类(Coccinellidae)等天敌有所减少;还有一些天敌,由于发生数量较少,不易与免耕法对照区进行比较。当使用广谱性化学杀虫剂进行树上喷雾时,覆盖作物对于受到化学杀虫剂干扰的苹果树上小花蝽O.minutus(Linnaeus)种群的恢复与建立有着促进作用。     

东亚小花蝽触角的扫描电镜观察

东亚小花蝽Orius sauteri(Poppius)是我国北方小型农林害虫的重要捕食性天敌昆虫,在天敌昆虫生产及防治害虫应用上具有较大价值。为了深入了解其化学感受系统,揭示东亚小花蝽的捕食行为机制,有必要对其触角结构及感器进行超微结构分析。本研究应用扫描电镜技术观察了东亚小花蝽1~5龄若虫及雌、雄成虫触角的结构和感器的类型、分布及超微结构。结果表明,东亚小花蝽1~5龄若虫及雌、雄成虫触角均为线状,分为柄节、梗节和鞭节(2亚节),随着东亚小花蝽生长发育,触角总长度及各节长度均显著增加,各节直径的增加不显著。东亚小花蝽触角上有5种感器,分别为毛形感器、刺形感器、锥形感器、具弯钩形感器和钟形感器,其中毛形感器和刺形感器各有2种亚型,钟形感器仅在1龄若虫触角上存在,2~5龄若虫及成虫触角上该感器退化消失。雄成虫触角感器数量明显多于雌成虫,若虫感器数量比成虫少。不同类型的感器在触角各节上的数量与分布各不相同。东亚小花蝽触角大小和感器的种类及数量随生长发育而变化,成虫触角感器存在性二型现象。     

释放东亚小花蝽对大棚辣椒上几种害虫的防治效果

大棚内辣椒上释放东亚小花蝽Orius sauteri防治朱砂叶螨Tetranychus cinnabarinus、蓟马和蚜虫,并在苗期释放时利用天敌贮备植物万寿菊Tagetes eracta辅助建立种群。结果表明,按0.5头.m-2和1头.m-2释放东亚小花蝽对朱砂叶螨、蓟马在释放5～7周时防治效果达到97.20%～99.95%;对于蚜虫,按0.5头.m-2释放东亚小花蝽,防治效果仅22.78%,而1头.m-2释放防治效果最高可达96.39%。东亚小花蝽释放可以用于控制大棚辣椒小型害虫。     

Residual toxicity of lambda-cyhalothrin on apple foliage toAmblyseius fallacis and the tarnished plant bug,Lygus lineolaris

The residual toxicity of lambda-cyhalothrin on leaves from a treated apple orchard to a mite predator,Amblyseius fallacis (Garman), in the laboratory, declined to one-third of its original level within 3 weeks. The absence ofA. fallacis on apple trees during the pink bud stage coupled with the results of this study pave the way for the development of integrated pest management strategies where key pre-bloom pests, such as the tarnished plant bug,Lygus lineolaris (Palisot de Beauvois), may be controlled with lambda-cyhalothrin with little if any toxic effects to the predator later in the season. Two years of field testing indicated that 10 g a.i./ha of lambda-cyhalothrin applied at pink was very effective against the tarnished plant bug.     

Transformation of soil microbial community structure and rhizoctonia-suppressive potential in response to apple roots

ABSTRACT Changes in the composition of soil microbial communities and relative disease-suppressive ability of resident microflora in response to apple cultivation were assessed in orchard soils from a site possessing trees established for 1 to 5 years. The fungal community from roots of apple seedlings grown in noncultivated orchard soil was dominated by isolates from genera commonly considered saprophytic. Plant-pathogenic fungi in the genera Phytophthora, Pythium, and Rhizoctonia constituted an increasing proportion of the fungal community isolated from seedling roots with increasing orchard block age. Bacillus megaterium and Burkholderia cepacia dominated the bacterial communities recovered from noncultivated soil and the rhizosphere of apple seedlings grown in orchard soil, respectively. Populations of the two bacteria in their respective habitats declined dramatically with increasing orchard block age. Lesion nematode populations did not differ among soil and root samples from orchard blocks of different ages. Similar changes in microbial communities were observed in response to planting noncultivated orchard soil to five successive cycles of 'Gala' apple seedlings. Pasteurization of soil had no effect on apple growth in noncultivated soil but significantly enhanced apple growth in third-year orchard block soil. Seedlings grown in pasteurized soil from the third-year orchard block were equal in size to those grown in noncultivated soil, demonstrating that suppression of plant growth resulted from changes in the composition of the soil microbial community. Rhizoctonia solani anastomosis group 5 (AG 5) had no effect on growth of apple trees in noncultivated soil but significantly reduced the growth of apple trees in soil from third-year orchard soil. Changes in the ability of the resident soil microflora to suppress R. solani AG 5 were associated with reductions in the relative populations of Burkholderia cepacia and Pseudomonas putida in the rhizosphere of apple.     

应用伪钝绥螨防治苹果全爪螨初报

伪钝绥螨是叶螨的有效天敌,1986年引入天水,1987、1988年在苹果园进行了释放试验,6月中、下旬按1:50的益害比释放于苹果树上,结果表明经过35～40天,苹果全爪螨从峰期(1987、7、31)7.79头/叶和(19888、2)21.84头/叶开始减退,至50～60天,分别减退为1.76头/叶和1.90头/叶,而对照树分别为19.43头/叶(8、20)和44.15头/叶(8、2)。该螨对苹果全爪螨越冬卵的控制效果明显,释放树平均一年生枝条单枝含卵量为15.95粒,化防树为93.64粒。     

释放巴氏钝绥螨对温室大棚茄子上西花蓟马及东亚小花蝽数量的影响

在北京市门头沟碧琨种植中心的温室大棚茄子上释放巴氏钝绥螨后,调查统计对茄子上西花蓟马及东亚小花蝽数量的影响。结果表明:释放巴氏钝绥螨对温室大棚茄子上的西花蓟马的种群数量在其高峰期具有一定的压低作用,尤其是释放200头/m2巴氏钝绥螨效果更好。温室大棚茄子上自然发生的本地天敌东亚小花蝽的种群数量,在各处理间的总体趋势相同,随着西花蓟马的数量变化而变化。     

Bait twig method for soil detection of <Emphasis Type="Italic">Rosellinia necatrix</Emphasis>, causal agent of white root rot of Japanese pear and apple,at an early stage of tree infection

Mulberry twigs were inserted into the soil as bait to detect Rosellinia necatrix at an early stage of tree infection in the orchard. R. necatrix was frequently trapped on twigs near the trunk base at soil depths of 6–20 cm within 10–20 days in May–July, suggesting that the incubation period was dependent on soil temperature. Subsequently, we inserted twig in the soil around healthy-looking trees in naturally infested orchards. R. necatrix was trapped from 80.0% of Japanese pear and 75.0% of apple trees that later proved to be infected. This bait twig method facilitated quicker diagnosis of white root rot on Japanese pear and apple at early stages of infection and can be used to detect recurrence of the fungus after fungicide treatment.