【作者】 田军；

【导师】 马玲；

【作者基本信息】 东北林业大学 ， 森林保护学， 2009， 硕士

【摘要】 白蜡吉丁柄腹茧蜂Spathius agrili Yang(膜翅目Hymenoptera:茧蜂科Braconidae)是在天津地区新发现的外寄生于白蜡窄吉丁Agrilus planipennis Fairmaire幼虫的重要天敌,对寄主害虫的控制作用较强,具有良好的生物防治利用前景。为有效利用该天敌,本文主要研究了人工繁育技术、测定了温度对其生长发育和繁殖的影响、筛选出沙蒿尖翅吉丁Sphenoptera sp.作为替代寄主用于人工繁育、并对白蜡吉丁柄腹茧蜂进行了林间初放试验;本文还从行为生态学和化学生态学角度研究了挥发性气味源在该蜂寻找寄主中的作用,以深入了解其寄主定位机制,并通过扫描电镜实验观察了白蜡吉丁柄腹茧蜂的触角及其触角感器结构。主要结论如下:研究了不同温度(22、24、26、28、30和32℃)对白蜡吉丁柄腹茧蜂生长发育及繁殖的影响。结果表明,在22～32℃范围内,白蜡吉丁柄腹茧蜂的卵、蛹及世代发育速率都是随着温度的升高而加快,而幼虫的发育速率在26℃时最快。卵、幼虫、蛹和世代的发育起点温度分别为14.34℃、16.89℃、14.16℃和13.84℃,有效积温分别为24.59、61.16、166.27和276.80日·度。温度对白蜡吉丁柄腹茧蜂的寄生率、寄生成功率、产卵量、子代蜂数量和性比都有不同程度的影响。结合发育历期的结果,认为适于人工繁育的温度范围为26～28℃。实验设计了5种繁蜂方法,其中枝干法、木段法和纸包法取得了成功。采用木段法时寄生率最高,达87.50%,平均产卵量为8.67粒,缺点是工作量较大;枝干法的寄生率为46.67%,平均产卵量为6.14粒,优点是工作量较小;纸包法的寄生率很低,达不到繁蜂要求。经比较认为枝干繁蜂法操作简单,工作量小,较适宜人工繁育,但寄生率相对木段法要低,仍需改进。替代寄主的筛选是人工繁蜂过程中的一个关键,本实验在白蜡吉丁柄腹茧蜂自然生境选取了一些钻蛀性害虫的幼虫和吉丁科的幼虫进行接蜂试验,其中沙蒿尖翅吉丁Sphenoptera sp.的幼虫可以被茧蜂成功寄生。为探讨该蜂用于生物防治白蜡窄吉丁的可行性,对其进行了林间放蜂初试。试验林放蜂前的寄生率为15.38%,翌年的4月为53.85%,寄生率有明显的提高,9月的寄生率亦保持在46.15%,放蜂效果明显。通过Y-型嗅觉仪对雌蜂进行了行为测定,结果表明:不同气味源对寄生蜂的诱引作用表现为受害白蜡树叶＞健康白蜡树叶=受害白蜡树皮＞健康白蜡树皮＞寄主幼虫＞虫粪,其中白蜡吉丁柄腹茧蜂对受害白蜡树皮的趋性显著(p＜0.05)。而对健康白蜡树叶无显著趋性(p＞0.05),说明白蜡吉丁柄腹茧蜂对寄主栖境的选择主要利用来自受害白蜡树叶所提供的信息。而这种信息可能来自于虫害诱导的植物挥发物,也可能是与寄主植物和虫害产生的协同增效作用有关用触角电位(EAG)的方法测试白蜡吉丁柄腹茧蜂触角对4种味源挥发物的电生理反应,结果显示其对4种刺激源的EAG反应的相对值大小依次为:受害白蜡树树叶＞寄主幼虫虫粪＞受害部树皮＞寄主幼虫。其中受害白蜡树树叶与空白对照、受害白蜡树树叶与寄主幼虫差异显著(P＜0.05)。该实验结果与行为生测结果较为一致。用扫描电镜(SEM)观察了该蜂触角及感觉器:该蜂触角呈丝状,雌雄个体触角表面所分布感器种类有所不同。雌蜂触角表面分布:毛形感器、板形感器、刺形感器、锥形感器和钟形感器;雄蜂触角感器种类稍少,只有毛形感器、板形感器和刺形感器。这种两性差异主要与雌雄蜂特有的行为有关,由此推测锥形感器和钟形感器在该蜂寄主定位过程中起着重要作用。更多还原

【Abstract】 Spathius agrili Yang(Hymenoptera:Braconidae) is an important ectoparasitic wasp of the Agrilus planipennis Fairmaire(Coleoptera:Buprestidae) larvae.This parasitoid has the potential to use as an excellent biological control agent for suppressing populations of its host. In order to utilize this natural enemy,the mass rearing techniques,Effects of temperature on development and reproduction ofS.agrili,Sphenoptera sp.was used as a host for rearing of S. agrili and the inundative release experiments were conducted in field were mainly studied. This article studied the responses of S.agrili to volatiles by chemical ecology and behavior ecology to find the role of phytochemicals in host-finding of S.agrili.The main results are summarized as follows.The study on the growth,development and reproduction of S.agrili at 6 differernt temperatures(22℃,24℃,26℃,28℃,30℃,32℃).The results showed that the developmental rate of egg,pupa and the whole generation of Spathius agrili yang increased with the rise of temperature from 22℃to 32℃,but the developmental rate of larva was highest at 26℃.The developmental threshold temperature required for egg,larva,pupa and whole generation was 14.34℃,16.89℃,14.16℃and 13.84℃,while the effective accumulated temperature was 24.59,61.16,166.27 and 276.80 degree_day,respectively.Temperature had different level effects on parasitic rate,the rate of successful parasitism,egg number,number of generations and sex ratio of S.agrili.The results showed that the temperature from 26℃to 28℃was suitable for the development and reproduction of S.agrili.This experiment designed five inoculating ways to mass rearing with stem-way,timber-way and wraped paper-way successfully reproducing the wasp.The parasitic rate was the largest when employing timber-way,reaching up to 87.50%and the average egg number was 6.14.The advantage of this way was less work;the parasitic rate was much lower in wraped paper-way which could not meet the requirement for reproducing parasitoids.After comparing these ways,the operation of stem-way was more simple and less labourious which was fit for mass rearing but the parasitic rate was relatively lower,in comparision with timber-way,and needed more improvement.Screening substitute hosts was a key factor in the process of mass rearing.This experiment has selected some larvaes of wood borers from parasitoid’s natural surroundings and the larvae of Bupresidae to mass rearing.The rescult shows that Sphenoptera sp.could be successfully parasitized by S.agrili.To explore the possibility for S.agrili manage the A.planipennis,the field release was conducted.The parasitic rate was 15.38%before releasing parasitoid in the field.The parasitic rate was 53.85%next April which witnessed a remarkable increase in parasitic rate while the parasitic rate maintained above 46.15%,showing a huge effect.The female’s behaviour was investigated by Y-tube olfactometer.The results indicated different volatile had such attraction to wasp that the leaves attracted by host＞healthy leaves= the bark attracted by host＞healthy bark＞host larvae＞frass,and the parasitoid showed preferences to the leaves attracted by host(p＜0.05) while there was no preferences to healthy leaves(p＞0.05),this indicated that the choice for hosts’ residents of S.agrili mainly depended on the information given out by the leaves attracted by host.This information might come from plants’ volatiles induced by pests and have something to with the cooperative effect between host plants and pest injury.EAG was used to test the S.agrili’s antenna EAG response to four kinds source of volatiles and the results showed the relative value of EAG response to four kinds source was as follows:the leaves attracted by host＞frass＞the bark attracted by host＞host larvae.The rescults also showed the significant EAG responses difference between the leaves attracted by host and blank,while between leaves attracted by host and host larvae(P＜0.05).These results in this experiment were coherent with the results of Y-tube olfactometer.Antennae and their sensilla of S.agrili were observed using scanning electron microscopy. Both sexes of antenae were threadlike.Five types of sensilla were found on the antennae of female.They are sensilla trichodea,sensilla chaetica,sensilla placodea,sensilla basiconca and sensilla campaniformia,respectively.But only there types of sensilla were found on the antennae of male.The difference between sexes mainly related to the unique behaviour of females and males,so it could be presumed that sensilla basiconca and sensilla campaniformia play a greatly important role in host location.更多还原