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BACKGROUND: The use of Trichogramma species is a potential key strategy in integrated pest management. However, its effectiveness depends on the use of chemicals that do not interfere with parasitism and parasite population growth. Here, a study was made of the effects of synthetic insecticides on Trichogramma pretiosum and Trichogramma exiguum in different hosts (Ephestia kuehniella, Plutella xylostella and Spodoptera frugiperda) and the influence of International Organisation for Biological Control (IOBC/WPRS) methodology in selectivity studies using different Trichogramma species. The insecticides used were commercial formulations (triflumuron at a concentration of 0.2 mL L?1 water, etofenprox at a concentration of 0.47 mL L?1 water and endosulfan at a concentration of 7.5 mL L?1 water); the control treatment consisted of distilled water. Eggs attached to cardboard cards were offered to parasitoids inside glass cages. Parasitised eggs, parasitism and adult emergence rates and parasitism reduction were evaluated. RESULTS: Endosulfan and etofenprox, classified as class‐4 toxic products, were extremely toxic to the parasitoids. Triflumuron, classified as a non‐toxic product, was selective to the parasitoids in eggs of all hosts. CONCLUSIONS: The methodology recommended by IOBC/WPRS influenced results regarding the use of different species of parasitoids, and the use of a single parasitoid species in their experiment is questionable. Copyright © 2011 Society of Chemical Industry 相似文献
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Abstract Cohorts of newly laid egg masses of two pod‐sucking bugs, Nezara viridula and Piezodorus hybneri (Hemiptera: Pentatomidae), were exposed to naturally occurring predators and parasitoids on soybean in unsprayed fields at four sites in Northern Sumatra. The fate of the young stages was recorded until the late first instar, before the nymphs start to disperse and feed. Partial life tables showed that mortality of N. viridula until the late first instar was 50–87%, of which 18–65% occurred during the egg stage and was mainly caused by predation; 2–26% of the eggs died of parasitism. P. hybneri which was present at only two sites, showed a 73–89% mortality until the late first instar, of which 69–85% was during the egg stage and, again, mainly caused by predation; 15–24% of the eggs died of parasitism. To evaluate the role of individual egg predator species in the field, we conducted hourly observations of exposed egg masses of the two pests. Dolichoderus sp., Solenopsis geminata (Hymenoptera: Formicidae), Paederus sp. (Coleoptera: Staphylinidae) and several gryllids (Orthoptera) were most commonly encountered feeding on the eggs. An index of ‘predation pressure”; was calculated from the densities of predators in the field and from an estimate of their attack rate based on field observations of predator feeding. Two sites with low predator pressures had low predation rates, while the two sites with high predation pressures had considerably higher predation rates. The implications of the findings for IPM training in soybean are discussed. 相似文献
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半自然条件下几种赤眼蜂及品系对亚洲玉米螟卵寄生能力比较 总被引：1，自引：0，他引：1
在半自然条件(田间网罩)下,将人工饲养的玉米螟卵按4、8、16块/株3个处理分别固定在网罩内的玉米植株中上部叶片上,然后每网罩分别引入供试赤眼蜂20头,24 h后更换玉米螟卵块,连续3 d。7 d后调查供寄生的玉米螟卵被寄生率及羽化率。结果表明:在半自然条件下广赤眼蜂伊朗1-1品系虽寄生能力高于其他供试品系,但到第2、3天明显降低;玉米螟赤眼蜂北京6-2-2品系每天均维持一个较平稳的寄生能力,产卵量在时间上的分配比较分散,并在第2、3天显示出比其他品系较高的寄生潜能。广赤眼蜂伊朗1-1品系的卵块寄生数量可随卵块密度的增加而增加,而其他品系则在各处理密度下,寄生数量基本没有变化;从卵粒寄生率看,广赤眼蜂伊朗1-1和吉林1-2两个品系的寄生数量随卵块密度的增加而大幅度提高,其他品系增加幅度较小。 相似文献
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载球孢白僵菌松毛虫赤眼蜂能够显著提高对亚洲玉米螟的防控效果,为了明确其对亚洲玉米螟卵期及幼虫期可持续防控的作用机理,采用松毛虫赤眼蜂吸附绿色荧光蛋白（GFP）标记的球孢白僵菌分生孢子,进行赤眼蜂载菌情况,以及亚洲玉米螟卵和幼虫的寄生、侵染过程观察。结果表明,赤眼蜂羽化后能够吸附柞蚕卵表面粘附的白僵菌分生孢子,并将其携带至亚洲玉米螟卵块表面,并吸附于未被赤眼蜂寄生的亚洲玉米螟卵孵化的幼虫体表,实现侵染并致死,幼虫带菌率达60.00%,网室内杀虫生物测定僵虫率达27.00%。本研究表明,载菌赤眼蜂在提高杀虫效率的同时实现害虫可持续防控,该方法为其他载菌天敌的应用提供了依据。 相似文献
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通过对玉米秸秆垛中越冬代亚洲玉米螟的调查数据分析,明确了吉林省中部地区(公主岭)越冬代玉米螟蛹的始见期、始盛期、高峰期、盛末期和终见期.通过对田间系统调查数据分析,明确了一、二代玉米螟卵的始见期、始盛期、高峰期、盛末期和终见期.一代玉米螟卵的孵化率达90%以上,卵很少被寄生和捕食,一代幼虫化蛹率为89%～94%.二代玉米螟的田间整个落卵期卵粒赤眼蜂寄生率达70%,卵被捕食和脱落很少,在9月12日左右二代老龄幼虫占92.7%,未见二代幼虫化蛹.研究表明吉林省中部地区玉米螟已由每年发生1.5代转变为每年发生2代.并对导致世代数变化的可能原因进行了讨论. 相似文献
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The present study was conducted to determine egg and larval parasitoids of the beet armywormSpodoptera exigua Hübner (Lepidoptera: Noctuidae), which is an important but sporadic pest in Turkey. High beet armyworm population levels were recently observed in fields of first and second crop maize in the southeast Mediterranean region of Turkey. The parasitoid species complex and its impact on the pest were analyzed in a 4-year study in first and second crop maize. The braconid larval parasitoidsMicroplitis rufiventris Kokujev,M. tuberculifer Wesmael,Meteorus ictericus Nees,Chelonus obscuratus (Herrich Schäffer) (an egg-larval parasitoid),Apanteles ruficrus (Haliday); the ichneumonid larval parasitoidsHyposoter didymator (Thunberg) andSinophorus xanthostomus Gravenhorst; and the egg parasitoidTrichogramma evanescens (Westwood) were found to be the natural enemies attacking the pest. Among the parasitoid species the solitary endoparasitoidH. didymator was the most prevalent species, being reared from 40.5% of the parasitized larvae found. Higher parasitism rates were recorded on first crop than on second crop maize in every year. Possible reasons for this difference in larval parasitism between two growing seasons include lower population of the pest and reduced insecticide applications in first crop maize fields which permitted higher parasitism. However, parasitoid activity was insufficient to counterbalance the population growth of the pest on subsequent second crop maize. 相似文献
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为评估赤眼蜂对大豆食心虫的生物防治潜能,采用室内接虫法和数学模型拟合法分别研究了黏虫赤眼蜂Trichogramma leucaniae、玉米螟赤眼蜂T.ostriniae和螟黄赤眼蜂T.chilonis对自然寄主大豆食心虫Leguminivora glycinivorella卵的寄生反应及其自身密度对寄主防控效果的影响。结果表明,3种赤眼蜂寄生大豆食心虫卵的数量均表现出随寄主密度的增大而增加的趋势,除寄主密度20粒卵外,3种赤眼蜂在其它寄主密度下的寄生数量均无显著差异。自身密度对3种赤眼蜂寄生作用均存在明显的干扰效应,表现出寻找效应随自身密度增加而降低的趋势,Hassell模型和Beddington模型均能较好地拟合赤眼蜂的寻找效应与其自身密度的关系,黏虫赤眼蜂、玉米螟赤眼蜂和螟黄赤眼蜂的寻找系数Q和攻击率a分别为0.3289、0.3270、0.2906和0.3267、0.3243、0.2853。在自身密度干扰作用下,3种赤眼蜂中,黏虫赤眼蜂对大豆食心虫表现出较好的防控潜能。 相似文献
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为探索南方稻区二化螟卵寄生蜂生防功能、评估卵寄生蜂在田间寄生动态并探讨对不同景观结构的响应,本文采用对比盆栽稻株叶片载卵、离体新鲜稻叶载卵和滤纸卵卡比对二化螟卵寄生蜂寄生率差异;利用盆栽稻株叶片载卵调查卵寄生蜂在稻田中的寄生率季节动态变化;在5月初、7月初和9月初分别调查了在不同景观样点二化螟卵寄生蜂寄生率,对不同空间尺度下（0.2,0.5,1.0,1.5,2.0 km）景观变量与卵寄生率进行模型分析,评估不同景观变量对卵寄生率的影响。结果表明,三种诱集方法差异显著,盆栽稻株叶片载二化螟卵被寄生的比率最高,其次为离体新鲜稻叶,滤纸卵卡效果最差。田间寄生动态调查表明,早稻卵被寄生比率偏低,中稻寄生率较高,在7月中旬二化螟卵被寄生率达到高峰（66.7%）,8月下旬以后,晚稻寄生率逐步下降。对不同空间尺度下景观结构变量与卵寄生率分析表明,1.5 km尺度下的林地与二化螟卵寄生蜂有着密切关系。低于40%林地面积比例时,二化螟卵寄生蜂寄生率随林地面积增加而降低;而在高于40%林地面积比例时,二化螟卵寄生率随林地面积增加而增加。综上所述,对于中国南方的小规模稻田景观,林地比例与二化螟卵寄生率有关,但相关效应并非单一地增加或减少的线性响应。研究结果可为南方稻区二化螟卵寄生蜂提供简便、有效的评估方法,并为综合利用二化螟卵寄生蜂控害功能,发展二化螟生防策略提供参考依据。 相似文献
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间作对甜玉米田主要害虫与天敌动态的影响 总被引：7，自引：5，他引：2
为明确甜玉米间作不同作物对害虫的控制作用,采用目测法系统调查了甜玉米单作、甜玉米与绿豆、菜豆、甘薯或花生间作生境玉米主要害虫和天敌种群发生动态,并比较了不同生境亚洲玉米螟的为害情况。间作生境中捕食性天敌蜘蛛和瓢虫类群的个体数量均明显增加,其中甜玉米间作绿豆或甘薯生境蜘蛛类群增长21%以上,瓢虫类群增长83%以上,显著高于甜玉米单作生境;不同生境间玉米螟赤眼蜂发生量差异不显著,对亚洲玉米螟卵的寄生率均达到86%以上。间作生境玉米生育期内亚洲玉米螟落卵量、斜纹夜蛾及玉米蚜发生量均与甜玉米单作无显著差异,但收获期甜玉米间作生境玉米螟为害率低于单作生境,其中以甜玉米间作绿豆生境最低,总蛀孔数和活虫数分别比单作生境下降55.72%和76.70%。表明间作不同作物对甜玉米田具有一定的控害增益作用。 相似文献
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短管赤眼蜂和夜蛾黑卵蜂防治草地贪夜蛾田间竞争的初步评价 总被引：1，自引：0，他引：1
短管赤眼蜂Trichogramma pretiosum与夜蛾黑卵蜂Telenomus remus均为草地贪夜蛾Spodoptera frugiperda卵期的重要寄生性天敌。为检验两种卵寄生蜂混合释放条件下的竞争能力,本试验于田间同时释放短管赤眼蜂和夜蛾黑卵蜂,统计分析了两种卵寄生蜂对草地贪夜蛾的寄生效能及种间竞争情况。结果显示,短管赤眼蜂对释放的草地贪夜蛾卵块的卵块寄生率为52.94%,卵粒寄生率为3.28%;对田间自然卵块的卵块寄生率为53.33%,卵粒寄生率为5.80%。夜蛾黑卵蜂对释放的草地贪夜蛾卵块的卵块寄生率为88.23%,卵粒寄生率为9.96%;对田间自然卵块的卵块寄生率为100.00%,卵粒寄生率为50.33%。在未进行放蜂处理的对照田中,未出现短管赤眼蜂,夜蛾黑卵蜂的卵块寄生率为23.57%,卵粒寄生率为7.67%。本研究结果表明,在高温高湿环境中,夜蛾黑卵蜂在田间竞争中处于优势。本研究结果将为利用卵寄生蜂防控草地贪夜蛾提供参考。 相似文献
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不同稻螟发生区螟卵寄生蜂的自然寄生作用 总被引：3，自引：0，他引：3
对江苏和安徽几个不同稻螟发生区螟卵寄生蜂的调查表明 ,稻螟赤眼蜂为优势种。在一代二化螟中 ,以二化螟特大发生的常熟地区稻螟赤眼蜂寄生率最高达 1 0 0 % ,每卵块羽化寄生蜂数也高达 82 3头 ;三化螟和二化螟发生均较重的安徽省和县稻螟赤眼蜂寄生率为 1 7 1 % ,每一卵块羽化的蜂仅 3 5头。由于地区间卵块大小有差别 ,寄生蜂对二化螟实际控制效果以金坛西部最高。一代三化螟中 ,常熟及金坛西部的寄生率均高达 1 0 0 % ,其它地区寄生率为 46 7%～ 79 1 % ,每一卵块羽化的蜂数则较少。赤眼蜂在不同代次螟虫间变动较大 ,金坛东部地区 ,一代二化螟到二代二化螟 ,每卵块寄生蜂数量由 3 8 3头下降为 0头 ,这主要是由于化学农药影响。在和县 ,寄生蜂随三化螟代次增加而增加 ,但在高淳 ,寄生蜂却在二代出现最低峰 ,三代最高。寄生蜂性比也因地区、螟虫种类和代次不同而变化。 相似文献
13.
松毛虫赤眼蜂对三种农田常用杀虫剂的敏感性 总被引：1，自引：0，他引：1
为明确常用杀虫剂对松毛虫赤眼蜂Trichogramma dendrolimi的安全性,室内评估了高效氯氰菊酯、阿维菌素和氯虫苯甲酰胺3种药剂对其成蜂的急性毒力以及田间推荐使用剂量对赤眼蜂各发育阶段的间接影响,并模拟自然情况,测定了不同残留期的3种药剂对赤眼蜂存活和寄生能力的影响.结果表明:以LC50进行评估,对松毛虫赤眼蜂毒力最高的为阿维菌素,其次是高效氯氰菊酯,氯虫苯甲酰胺毒力最小;在田间推荐使用剂量下,阿维菌素、高效氯氰菊酯和氯虫苯甲酰胺的安全系数分别为0.017、0.066和69.175;在推荐使用剂量下,氯虫苯甲酰胺处理含有不同发育阶段赤眼蜂的米蛾Corcyra cephalonica卵后,平均羽化率最高为90.43%,其次是高效氯氰菊酯为56.46%,阿维菌素仅为9.84%;接触0~7 d残留期阿维菌素的玉米叶片24 h,松毛虫赤眼蜂全部死亡,无米蛾卵被寄生,但接触3~7 d残留期氯虫苯甲酰胺的玉米叶片,赤眼蜂的死亡率和寄生米蛾卵数量与清水对照无明显差异.表明在实施释放赤眼蜂的害虫综合治理方案中,应尽量避免使用阿维菌素,而氯虫苯甲酰胺对赤眼蜂风险性极低,具有很好的相容性,可以推广使用. 相似文献
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A study was carried out at the Natural Park of Montesinho, NE Portugal, in order to evaluate the effect of different pine
species (Pinus pinaster Ait.,P. nigra Arn. andP. sylvestris L.) onThaumetopoea pityocampa populations. The structure of the egg batches, the impact of the egg parasitoids on natural mortality of the pest and the
species of parasitoids present, as well as their emergence dynamics, were analyzed. The length of the egg batches varied among
pine species with the longest ones onP. nigra. The mean number of eggs per batch differed betweenP. sylvestris and the two other hosts studied, with fewer eggs per batch on the first. No differences were found in the size of eggs among
pine species. The egg mortality varied between 25.8% and 33.0%, with no differences among hosts. Parasitism was the main cause
of death.Baryscapus servadeii (Mercet.) was the most abundant parasitoid species, followed byOoencyrtus pityocampae (Dom.) andTrichogramma embryophagum Htg.B. servadeii dominated in the egg batches collected fromP. pinaster andP. nigra, whereasO. pityocampae was most frequent onP. sylvestris. The emergence ofB. servadeii started in the middle of March and continued until August, with the emergence peak at the end of May. The emergence ofO. pityocampae started at the end of April and continued throughout September, with maximum values in June.
http://www.phytoparasitica.org posting Sept. 20, 2006. 相似文献
15.
G. A. Pak T. G. Van Heiningen F. A. N. Van Alebeek S. A. Hassan J. C. Van Lenteren 《European journal of plant pathology / European Foundation for Plant Pathology》1989,95(3):129-142
The effectiveness of inundative releases of four strains of the egg parasiteTrichogramma (Hymenoptera, Trichogrammatidae) to control five lepidopterous species infesting Brussels sprouts crops in the Netherlands was examined in small-scale field experiments in 1982–1985. Strains were selected on the basis of behavioural characteristics investigated in laboratory experiments, i.e. parasitization activity at low temperature and host-species preference.Mamestra brassicae (Noctuidae) was the most abundant host species. Its density usually averaged between 0.5 and 2.0 eggs/plant throughout most of the season (June–September). A very high peak density of 12 eggs/plant occurred in 1982. In other years the peak was below 2.5 eggs/plant.Correspondence between the observed patterns of parasitism and behavioural characteristics of the strains was in general present. A strain ofT. evanescens (no. 57), with a high activity at 12°C, performed best againstM. brassicae. However, even its highest rate of parasitism (52%) was not sufficiently effective. A strain ofT. maidis (no. 11) performed best againstPieris brassicae andP. rapae (Pieridae), but parasitism remained low (<30%) and was generally limited to peak densities (<0.5 eggs plant) occurring in 1982 and 1985.Plutella xylostella (Yponomeutidae) was an abundant species in some years, but parasitism of its eggs was never observed. Egg densities ofEvergestis forficalis (Pyralidae) remained low in all years. The relationship between parasitims and host density and the influence of the parasite-release rate are discussed. Low host densities may have been a limiting factor for effective parasitism.Samenvatting In spruitkool kan schade veroorzaakt worden door rupsen van vijf soorten Lepidoptera. Inundatieve biologische bestrijding met de eiparasietTrichogramma (Hymenoptera, Trichogrammatidae) zou een alternatief kunnen zijn voor intensieve chemische gestrijding. In veldexperimenten (1982–1985) is de effectiviteit van vierTrichogramma spp. stammen vergeleken om de uitkomsten van laboratoriumonderzoek naar criteria voor de selectie van geschikte natuurlijke vijanden te evalueren. Selectiecriteria zijn gebaseerd op eigenschappen van het zoek- en parasiteringsgedrag van de parasieten, o.a. parasiteringsactiviteit bij lage temperatuur en gastheer-preferentie.
Mamestra brassicae (Noctuidae) was de talrijkste gastheersooort, met een gemiddelde dichtheid van 0,2–2,0 eieren/plant gedurende een groot deel van het seizoen (juni–september). Een extreem hoge piekdichtheid (12 eieren/plant) deed zich voor in 1982. In andere jaren was de piekdichtheid ongeveer 2,5 eieren/plant. Eieren vanM. brassicae werden het meest geparasiteerd door stam 57 (T. evanescens), maar zelfs het hoogste gemiddelde seizoenspercentage parasitisme (52%) was niet voldoende voor een effectieve bestrijding. EenT. maidis stam (11) gaf de beste resultaten tegenPieris brassicae enP. rapae (Pieridae), maar parasitisme was laag (<30%) en vrijwel beperkt tot piekdichtheden hoger dan 0,5 eieren/plant, die voorkwamen in 1982 en 1985.Plutella xylostella (Plutellidae) was soms talrijk, maar eiparasitisme leek niet voor te komen. De dichtheid vanEvergestis forficalis (Pyralidae) was gering in alle jaren.Relatief lage gastheerdichtheden kunnen een beperkende factor geweest zijn voor het optreden van een effectieve percentages eiparasitisme. De resultaten tonen aan dat er een overeenstemming is tussen selectiecriteria die in het laboratorium zijn onderzocht en de effectiviteit van geselecteerde stammen in het veld. 相似文献
16.
三种赤眼蜂对灰白蚕蛾的卵龄选择 总被引：2，自引：2，他引：0
灰白蚕蛾Ocinara varia.是近年来华南地区为害较严重的园林害虫,为筛选有效防治灰白蚕蛾的赤眼蜂种,在室内条件下比较了短管赤眼蜂Trichogramma pretiosum、松毛虫赤眼蜂T.dendroli-mi和暗黑赤眼蜂T.euproctidis对不同卵龄灰白蚕蛾卵的寄生能力和适应能力.结果显示,随寄主卵龄的增加松毛虫赤眼蜂和暗黑赤眼蜂寄生卵数均呈下降趋势,且都在灰白蚕蛾卵龄为6h的卵上寄生卵数最多,分别为15.90粒/雌和12.20粒/雌;而短管赤眼蜂的寄生卵数随寄主卵龄的增加呈先上升后下降趋势,在卵龄为24 h时达最高,为8.25粒/雌;在各卵龄段,松毛虫赤眼蜂的寄生卵数均比其它2种蜂多;当寄主卵龄超过72 h时,3种赤眼蜂的寄生卵数均显著下降.3种赤眼蜂在寄生卵龄为6h的寄生卵上羽化率最高,当卵龄超过72 h时,其羽化率均显著下降.松毛虫赤眼蜂和暗黑赤眼蜂对6h卵龄的灰白蚕蛾卵致死能力最强,而短管赤眼蜂对24 h卵龄的灰白蚕蛾卵致死能力最强.综合分析表明,松毛虫赤眼蜂在灰白蚕蛾卵上的寄生能力和适应能力最好,是灰白蚕蛾的有效天敌. 相似文献
17.
Studies were carried out on the egg material ofTraumatocampa ispartaensis Doganlar & Avcı (Lep.: Notodontidae) collected onCedrus libani A. Rich. A total of 95 egg-batches were sampled over two annual generations ofTr. ispartaensis. The number of eggs in each egg-batch varied between 39 and 245 and the length of the batches varied between 7 and 36 mm.
The mean number of eggs per batch was found to be 119 and 122 in 1999 and 2000, respectively. Based on field data the oviposition
period continued from mid August to mid September. The mean hatching rate of the host was found to be 85.8% and 88.9%, whereas
the impact of egg parasitoids accounted for 11.3% and 7.4%, respectively in the 2 years.Ooencyrtus pityocampae (Mercet) was observed as the most abundant egg parasitoid, followed byOoencyrtus sp. nearmasii (Mercet) andTrichogramma brassicae Bezdenko. Based on the emergence dynamics of the egg parasitoids in the laboratory, it seems thatO. pityocampae emerged mainly in June whereasO. sp. nearmasii andT. brassicae emerged mainly in May.
http://www.phytoparasitica.org posting Feb. 3, 2003. 相似文献
18.
In Bulgaria near Marikostino, in a forest ofPinus nigra Arn. 239 egg batches were sampled over four generations ofThaumetopoea pityocampa (Den. & Schiff.) (Lep., Thaumetopoeidae) in various seasons. Directly after collection the batches were singled in test tubes,
closed with cotton stoppers and stored under laboratory conditions at 20–22°C.
Oviposition always started from the base towards the tip of the needles. The emergence of egg parasitoids was observed daily,
and the parasitoids were counted and identified.
The eggs from which parasitoids emerged were marked for further studies. After removing the adults and opening the eggs, the
impact of the species of parasitoids was evaluated by identifying the meconia and other rests (left overs).
Ooencyrtus pityocampae (Mercet) was the most abundant egg parasitoid, followed byAnastatus bifasciatus (Fonsc.). Only few individuals ofBaryscapus servadeii (Dom.) were collected. The hyperparasitoidBaryscapus servadeii (Dom.) were collected. The hyperparasitoidBaryscapus transversalis Graham, was found at low densities. Only a few eggs were parasitised byTrichogramma embryophagum Htg. Total mortality of the host eggs varied from 34.7 to 79.7% depending on the period of parasitism and on the numbers
of sterile eggs. The impact of the parasitoids was calculated to be 9.3–38.9%, depending on the period when parasitism had
taken place.
The mean number of eggs per batch varied from 203 to 253. The rate of parasitism was reduced by early sampling of the egg
batches. In some cases, a very high percentage (up to 29.2%) of undeveloped eggs was found. In all samples a small percentage
of empty eggs was always observed.
The research conducted was supported by the Government of Lower Saxony, Hannover, Germany. 相似文献
Untersuchungen zum Eiparasitismus von Thaumetopoea pityocampa bei Marikostino/Bulgarien w?hrend einer Vierjahresperiode (1991–1994)
Zusammenfassung In Bulgarien, in der N?he von Marikostino, wurden 239 Eigelege des PinienprozessionsspinnersThaumetopoea pityocampa (Den.& Schiff.) (Lep., Thaumetopoeidae) in einemPinus nigra Forst über 4 Generationen zu verschiedenen Jahreszeiten gesammelt. Die Gelge wurden sogleich einzeln in Reagensgl?ser gegeben, die mit Wattestopfen verschlossen wurden, und unter Laborbedingungen bei 20–22°C aufbewahrt. Die Eiablage fand stets von der Nadelbasis zur Spitze hin statt. Der Schlupf der Parasitoiden wurde t?glich registriert. Nach Entfernen der Gelegeschuppen wurde jedes Ei markiert, aus dem ein Parasitoid schlüpfte. Alle adulten Parasitoide wurden sogleich nach dem Schlupf entfernt und zur Determination vorbereitet. Nach Ende der Schlupfperiode (mindestens 1 Jahr nach dem Raupenschlupf) wurden alle Eier ge?ffnet. Der Einflu? der cinzelnen Parasitoiden-Arten auf die Eimortalit?t wurde anhand der Mekonien und Rückst?nde in den Eiern bewertet. Ooencyrtus pityocampae (Mercet) war in den Eiern die h?ufigste Art, gefolgt vonAnastatus bifasciatus (Fonsc.) VonBaryscapus servadeii (Dom.) wurden nur wenige Individuen gefunden. Auch der Hyperparasitoid,Baryscapus transversalis Graham, war nur in geringer Populationsdichte vertreten. Nur wenige Eier waren vonTrichogramma embryophagum Htg. parasitiert. Die Gesamtmortatit?t der Wirtstiere variierte von 34,7% bis 79,7%; sie war abh?ngig von der Parasitierungsperiode und der Menge an sterilen Eiern. Der Einflu? der Eiparasitoide betrug 32,7–38,9%, wenn sie die gesamte Embryonalentwicklung des Wirtes zur Parasitierung nutzen konnten. Die mittlere Anzahl der Eier pro Gelege variierte in den Sammelproben von 203 bis 253. Die Parasitierungsrate war nach frühem Einsammeln der Gelege (nach Oviposition des Wirtes) stark reduziert. In einigen F?llen war ein sehr hoher Prozensatz (bis zu 29,2%) an nicht entwickelten Eiern zu finden. In allen Eigelegen waren einige Eier vorhanden, die total leer waren.
The research conducted was supported by the Government of Lower Saxony, Hannover, Germany. 相似文献
19.
20.
Ophmella communa (Coleoptera: Chrysomelidae) is a biological control agent of Ambrosia artemisiifolia (Asterales: Asteraceae). To reveal its climate adaptation, the effect of temperature on life traits of Aenasius arizonensis, a parasitoid of Phenacoccus solenopsis was studied. The results showed that both the highest parasitism and emergence rates of A. arizonensis were observed at 31 °C. The parasitism and emergence rates of the parasitoid significantly increased with the increasing temperature from 19 °C to 31 °C, but dropped when the temperature exceeded 31 °C. Female ratio reached a higher value at 19, 22, 31, 34 or 37 °C. The minimum threshold temperatures for female and male parasitoids were 11.5 and 11.2 °C, respectively. The effective accumulative temperatures for the parasitoid to develop from eggs to both female and male adults were 222.2 day-degrees. Since the highest parasitism rate, the highest emergence rate and a higher female ratio were observed at 31 °C, we conclude that the optimum temperature for mass rearing of A. arizonensis is 31 °C in the insectary based on the results of our study. 相似文献