椰心叶甲的寄生性天敌——椰心叶甲啮小蜂和椰甲截脉姬小蜂的室内培育

开展对椰心叶甲的饲养及其两种寄生性天敌———椰心叶甲啮小蜂和椰甲截脉姬小蜂的培育繁殖研究。采用室内饲养培育为主,野外采集补充为辅的方法。饲养培育从原来采用的“两室繁蜂法”改进为现在的“五室繁蜂法”,椰心叶甲啮小蜂和椰甲截脉姬小蜂的日产量分别是原来的3倍和4倍,而且蜂种质量优良、寄生率高,能保证大田释放控制效果。椰心叶甲啮小蜂的大田寄生率一般为40%~50%,最高可达100%。椰甲截脉姬小蜂的大田寄生率一般为20%~30%,最高可达47%。     

三种杀菌剂对椰心叶甲啮小蜂和椰甲截脉姬小蜂羽化率的影响

椰心叶甲是棕榈植物上的重要入侵害虫。释放天敌寄生蜂可有效控制其对寄主的危害,是目前防治椰心叶甲最有效的手段。为验证杀菌剂对椰心叶甲天敌寄生蜂的影响,采用浸渍法测定了杀菌剂甲基硫菌灵、百菌清和咪鲜胺对椰心叶甲啮小蜂和椰甲截脉姬小蜂羽化率的影响。结果表明：蛹初期椰心叶甲啮小蜂与椰甲截脉姬小蜂经百菌清处理后,二者的羽化率都有所降低。咪鲜胺处理对两种寄生蜂的羽化率均无明显影响。蛹中期椰心叶甲啮小蜂用甲基硫菌灵处理后的羽化率降低极显著。此外,甲基硫菌灵对蛹初期和蛹中期的椰甲截脉姬小蜂有显著致死能力。因此,在使用寄生蜂防治椰心叶甲时,建议间隔使用甲基硫菌灵和百菌清;而咪鲜胺对两种寄生蜂安全,可以与寄生蜂同时使用。本结果对棕榈植物使用杀菌剂防治病害和使用寄生蜂防治椰心叶甲均有重要意义。     

低温贮藏对椰心叶甲啮小蜂寄生率及繁殖力的影响

在(13±1)℃的条件下,分别对椰心叶甲初蛹、被寄生的椰心叶甲僵蛹、椰心叶甲啮小蜂雌蜂进行低温贮藏,研究其对椰心叶甲啮小蜂寄生率及繁殖力的影响寻求其适宜的贮藏期。试验结果分析表明:椰心叶甲初蛹的贮藏期11 d为宜;被寄生的椰心叶甲僵蛹的贮藏期14 d为宜;空贮(不补充营养)椰心叶甲啮小蜂成蜂时,贮藏期2 d为宜,补充10%的蜂蜜水条件下,适宜贮藏期可延长到5 d。     

深圳市释放啮小蜂对椰心叶甲的控制作用

在深圳连续释放椰心叶甲啮小蜂防治椰心叶甲,结果表明:放蜂45d后,其中3个放蜂点的蛹寄生率分别为72.00%、92.78%和89.44%,椰心叶甲啮小蜂已在当地建立了一定的种群;180d后,各放蜂点的椰心叶甲虫口密度分别由87.4、78.4和133.0头/株(包含成虫、蛹和幼虫)下降到5.6、23.6和3.0头/株,此时椰心叶甲的种群密度不足以对椰树或其他棕榈植物造成严重危害。说明在城市内利用寄生蜂控制椰心叶甲是可行的。     

椰心叶甲人工饲料的研制及应用效果评价

为了获得入侵害虫椰心叶甲Brontispa longissima(Gestro)的人工饲料,在分析其天然寄主叶片水分和营养成分基础上,借鉴其它鞘翅目昆虫人工饲料配方,进行椰心叶甲人工饲料的配制和筛选,并评价人工饲料饲养的椰心叶甲对其寄生蜂椰甲截脉姬小蜂Asecodes hispinarum和椰心叶甲啮小蜂Tetrastichus brontispae的适合性。人工饲料配方的成分:蔗糖4%、椰子粉2%、大豆粉2%、椰树叶粉10%、酵母2%、维生素E 0.3%、抗坏血酸0.2%、对羟基苯甲酸甲酯0.2%、琼脂4%、链霉素0.03%和水75%。用所配制的人工饲料饲养椰心叶甲初孵幼虫,其蛹成活率可达36%,蛹羽化率与对照无显著差异,均在90%以上;雌成虫占52.4%,与对照无显著差异。表明人工饲料饲养所得的椰心叶甲可用于其幼虫寄生蜂椰甲截脉姬小蜂和蛹寄生蜂椰心叶甲啮小蜂的扩繁。     

椰心叶甲的重要寄生蜂--椰扁甲啮小蜂

本文主要介绍了椰扁甲啮小蜂的形态特征、分布、寄主、生物学以及其作为椰心叶甲生防物的作用.     

低温贮藏对椰心叶甲啮小蜂羽化率及出蜂量的影响

椰心叶甲啮小蜂(Tetrastichus brontispae Ferrière)是椰心叶甲(Brontispa longissima Gestro)的重要性寄生天敌之一,其寄生性专一,主要寄生椰心叶甲的蛹[1].     

椰心叶甲啮小蜂转录组分析及基因功能注释

椰心叶甲啮小蜂Tetrastichus brontispae Ferrière可以有效地防治椰心叶甲Brontispa longissima（Gestro）危害，但是由于缺乏相关的遗传信息，其分子生物学的相关研究仍然较少。本研究通过Illumina测序平台，对椰心叶甲啮小蜂进行转录组测序。经De Novo拼接后，共获得29535条Unigene，进一步将Unigene与NR、GO、eggNOG和KEGG四个数据库进行比对，结果表明，共有13796条Unigene被注释。在NR数据库中注释到13401条Unigene，与丽蝇蛹集金小蜂Nasonia vitripennis相似的基因序列最多；根据GO数据库，将3834条Unigene归类为三大类67个功能组；eggNOG数据库将12707条Unigene分25个功能分类；KEGG数据库将5999个Unigene分为五大类。对椰心叶甲啮小蜂进行转录组测序和基因功能注释，可以为今后研究该蜂的遗传多样性、基因功能挖掘等提供数据支撑。     

椰心叶甲啮小蜂复眼的扫描电镜观察

椰心叶甲啮小蜂Tetrastichus brontispae是椰心叶甲Brontispa longissima的寄生性天敌。研究该小蜂的行为发现,雄蜂复眼在交配过程中起重要作用,为此利用扫描电镜对其复眼进行观察。结果表明：雌蜂复眼长椭圆形,外凸,小眼约267个;雄蜂复眼近椭圆形,略外凸,小眼约285个。雌、雄蜂复眼中心区域小眼排列较紧密,多为较规则的六边形,边缘区域小眼排列不紧密,多为不规则四至六边形,且少量相邻小眼的间距较大。雌、雄蜂复眼小眼面积分别为124.931、19.90μm2。雌、雄蜂复眼中心区域近背区小眼间着生少量感觉毛。     

绿僵菌与椰甲截脉姬小蜂对椰心叶甲的协同控制作用

在室内条件下,研究了金龟子绿僵菌小孢变种Metarhizium anisopliae var. anisopliae侵染和椰甲截脉姬小蜂Asecodes hispinarum寄生两种生防措施之间的相互影响,并对两种措施协同控制椰心叶甲Brontispa longissima的效果进行了评价。结果表明,绿僵菌菌株HK4对椰甲截脉姬小蜂成虫安全;但绿僵菌侵染使姬小蜂对椰心叶甲的寄生率显著降低。在先接种绿僵菌后接入姬小蜂的情况下,椰甲截脉姬小蜂对椰心叶甲的寄生率仅为10.23%,显著低于其单独寄生的寄生率79.55%;绿僵菌对椰心叶甲的侵染率为96.59%,高于绿僵菌单独处理的侵染率84.09%,但不显著。而在先接蜂后接种绿僵菌的处理中,绿僵菌对椰心叶甲的侵染率仅为69.09%,显著低于绿僵菌单独处理。对椰心叶甲的生测结果显示,先接种绿僵菌再接入姬小蜂、先姬小蜂寄生再接种绿僵菌、同时接种绿僵菌和接入姬小蜂3种处理的校正死亡率分别为100%、100%、98.86%,显著高于绿僵菌单独侵染和姬小蜂单独寄生。     

亚洲玉米螟一、二代成虫扩散规律研究

１９９１－１９９２年在河北省衡水市亚洲玉米螟一、二代成虫盛发期，在田间释放用人工饲养、苏丹蓝Ⅱ标记的玉米螟成虫３４万头，在距释放点１、２、４、６、８、１０、２０、３０、４０、５０ｋｍ处设点回收，以研究玉米螟田间扩散规律和远距离迁飞的可能性。用玉米螟性诱剂回收时，两年回收到标放雄蛾一代分别为１１９和１９５头，二代分别为５３和２４９头，回收到标记蛾距释放点的最远距离均８ｋｍ，其中１－２ｋｍ范围内回收到     

温室条件下丽蚜小蜂的扩散行为

丽蚜小蜂Encarsia formosa是粉虱类害虫的重要寄生性天敌，目前已广泛应用于设施蔬菜烟粉虱Bemisia tabaci和温室白粉虱Trialeurodes vaporariorum的防控。本文在温室条件下对丽蚜小蜂的扩散行为进行了研究，并分析了扩散距离、释放时间等因素对其寄生率的影响。结果表明，丽蚜小蜂成虫释放后其扩散行为是渐进的、不连续的，主要在1~4 m范围内扩散，少量个体可扩散至6~8 m。番茄植株高度对丽蚜小蜂寄生率没有明显影响，这说明其释放后可成功地搜索到不同高度植株上的寄主。丽蚜小蜂释放后第2 d，距释放点l和2 m处其寄生率分别为92.5%和85.3%；释放后4 d，距释放点l和2 m处其寄生率分别为53.1%和39.7%。同一释放时间距释放点l和2 m处丽蚜小蜂寄生率没有显著差异，但却显著高于距释放点4、6和8 m处丽蚜小蜂的寄生率。因此，从寄生率也可以看出丽蚜小蜂成虫主要在1~4 m范围内进行扩散。利用丽蚜小蜂的有效扩散距离和寄生率可以确定其在温室的释放数量、释放点之间的距离和释放次数，研究结果对于更好地发挥丽蚜小蜂在生物防治中的控害作用具有重要的应用意义。     

Dispersal of Avena fatua and Avena sterilis patches by natural dissemination, soil tillage and combine harvesters

The dispersal of Avena spp. (A. fatua and A. sterilis) by natural dissemination and by agricultural operations was studied in four experiments conducted in Spain and Britain. Natural dispersal was very limited, with a maximum dispersal distance of 1.5 m. Dispersal was higher in the geographic direction that was downwind than in any of the other three geographic directions. Although plant movement was very small under no‐tillage, an annual patch displacement of 2–3 m in the tillage direction was observed under conventional soil tillage. Ploughing downhill resulted in much larger dispersal distances than ploughing uphill. In the crops studied, combine harvesters dispersed few Avena spp. seeds, because of the fact that the plants had shed most of their seeds (>90%) before harvest. The percentage of seeds available to be dispersed by the combine was dependent on the harvest time. Although combine harvesting may not contribute much to short‐distance dispersal, it may play an important role in long‐distance dispersal. In our studies, isolated plants were located up to 30 m from the original sources. This small proportion may have a significant effect on the distribution of the weed within a field, acting as foci for new patches.     

Secondary dispersal, spatial dynamics and effects of herbicides on reproductive capacity of a recently introduced population of Bromus sterilis in an arable field

An arable field was subdivided and subjected to either deep inversion ploughing or non‐inversion cultivation after viable seeds of Bromus sterilis had been sown into oilseed rape stubble. After sowing in isolated plots distributed within the field, sequences of cropping treatments for the establishment of two successive winter wheat crops were applied. Each subfield was split into an uphill and a downhill direction for soil cultivation. The field had a 10° slope. In the season following seed introduction, 2.6% of the introduced seeds had successfully germinated and established in the non‐inversion cultivation regime, when no effective graminicide was applied. Ploughing eradicated B. sterilis. Using differential global positioning system (DGPS) mapping of the whole field population, emerged plants were observed up to 8.7 m (uphill treatment) and 21.3 m (downhill treatment) of their initial source. The median distance seeds were transported was 2.3 m uphill and 4.8 m downhill. Post‐emergence application of the herbicide propoxycarbazone slightly reduced weed density and seed weight, and almost halved weed seed production. Application of fenoxaprop‐P‐ethyl was followed by higher density of plants, tillers and seeds of B. sterilis. Seed viability was unaffected by herbicide use. Thus, in the second wheat crop following seed rain, the weed population was dispersed more widely in the field, such that 20–30% of seeds were dispersed more than 5 m distance from the first year's foci of infestation. The relevance of soil cultivation to secondary dispersal of B. sterilis is discussed.     

青岛地区暗黑鳃金龟性信息素鉴定及田间应用技术

为深入了解国内暗黑鳃金龟Holotrichia parallela Motschulsky种群的性信息素组分及其田间引诱效果,采用气质联用技术对其雌性信息素进行了分离鉴定,利用标记-回捕技术测试了5 h内暗黑鳃金龟的扩散距离,并在此基础上测试了诱捕器颜色、离地高度、密度、单诱芯性信息素含量等对田间诱虫效果的影响。结果表明：L-异亮氨酸甲酯和（R）-（-）-芳樟醇为国内青岛种群暗黑鳃金龟雌虫性信息素的主要组分,两者含量比为7：1;暗黑鳃金龟5 h扩散距离可达400 m以上,平均扩散距离为55.9 m,扩散距离在20~60 m的个体占总虫数的77.5%;黄色诱捕器对该虫的引诱效果显著优于黑色和绿色;诱捕器离地2 m引诱到的试虫数目显著高于1、1.5、2.5和3 m;单个诱芯性信息素含量360 mg引诱效果最好,显著高于180 mg及以下浓度;诱捕器间隔20~60 m防治效果较好,结合使用成本和试虫扩散距离,间距60 m最优。     

Splash dispersal of conidia of Mycocentrospora acerina in the field

The dispersal of conidia of Mycocentrospora acerina was studied in caraway field trials. A Burkard spore trap, rotorods, inverted Petri dishes containing sucrose agar and rain gauges were used to trap conidia of M. acerina . Sporulation was stimulated by rainfall (2 mm) and moderate temperatures (around 15°C). Solar radiation had a negative effect on sporulation. Hardly any conidia were found in the spore traps on rainless days. Short distance (9 m) spread of M. acerina is mainly caused by splash dispersal of its conidia. Trap plants at 0, 0.1, 1 and 4 m from the inoculum source were readily infected under moist conditions. Beyond 9 m from an inoculum source no infection of caraway trap plants was found. Trap plants at 9 m from an inoculum source were infected in one out of three seasons only. Long distance (>9 m) spread could not be demonstrated by the techniques used in this study. The results suggest that, usually, a caraway field is infected by inoculum sources within that field.     

Horizontal spread of beet necrotic yellow vein virus in soil

Horizontal dispersal of beet necrotic yellow vein virus (BNYVV) by means of viruliferous zoospores ofPolymyxa betae was studied in greenhouse experiments. BNYVV was not detected in roots of sugar beet plants grown in silver sand for 4 weeks at a root-free distance of 5 cm from eitherP. betae- and BNYVV-infected plants or BNYVV-infested soil. Spread of BNYVV from inoculum sources in the field was studied in the absence and presence of tillage practices. Active dispersal in combination with root growth from and towards point sources of inoculum contributed only little to horizontal dispersal of viruliferous inoculum and spread of disease during the season, as determined for one soil type, two different years and in the absence of tillage and tread. In the second beet crop after application of inoculum to whole field plots, more BNYVV-infected plants were detected at 2 m than at 8 m distance from the infested plots in the tillage direction. In the third year, disease incidence at 8 m was high and equivalent to that at 2 m.     

亚洲玉米螟越冬代成虫扩散行为与迁飞可能性研究

作者于1987和1988两年在河北省衡水市当地越冬代亚洲玉米螟成虫盛发期,采用人工标放回收方法对其扩散行为及迁飞可能性进行了研究。两年分别释放人工饲养的标记玉米螟成虫15万和Lipaphis erysimi(kaltenbach), diamondback moth60万头,在45.5km半径范围内分别回收到标记雄蛾461和2650头,首次明确了我国北方亚洲玉米螟越冬代成虫的田间扩散飞行规律,95％集中在距释放点4km半径范围内;部分个体可扩散到6—30km半径范围内,最远距释放中心45.5km。成虫扩散飞行受风力、风向和温度影响。结果表明,亚洲玉米螟虽有远距离迁飞的潜力,但至少在越冬代发生期基本不存在大量远距离迁飞的可能性。