寄主树木、寄主和环境因子对松褐天牛深沟茧蜂寄生率的影响研究

[目的]松材线虫病是我国对森林危害和威胁最严重的病害,控制其传播媒介昆虫松褐天牛是防治松材线虫病的主要手段。作者发现的松褐天牛深沟茧蜂(Iphiaulax monochamusi Yang)是寄生松褐天牛中老龄幼虫的重要天敌。为明确松褐天牛深沟茧蜂的寄生率与寄主树木、寄主和环境因子的关系,开展了本研究。[方法]通过解剖46株松褐天牛危害致死的马尾松,调查了松褐天牛深沟茧蜂寄生率与马尾松、松褐天牛和环境因子之间的关系。[结果]调查研究表明:寄主树木的高度、胸径和树龄对松褐天牛深沟茧蜂寄生率没有显著影响,松褐天牛的数量对松褐天牛深沟茧蜂寄生率亦没有显著影响,而松褐天牛幼虫龄期和松褐天牛幼虫在树干上的位置显著影响松褐天牛深沟茧蜂寄生率。松褐天牛深沟茧蜂寄生率与松褐天牛龄期呈显著正相关,其偏好寄生3~5龄幼虫;就天牛在其危害寄主树木上的位置而言,松褐天牛深沟茧蜂偏好寄生马尾松主干上部和在韧皮部危害的松褐天牛幼虫,其对位于马尾松树干上部的寄主幼虫寄生率最高,达27.38%,对在韧皮部生活、危害的寄主幼虫寄生率为20.18%,显著高于位于木质部生活的寄主幼虫寄生率(5.46%)。逐步回归分析表明:影响松褐天牛深沟茧蜂寄生率的关键环境因子是寄主树木的坡位和其它天敌寄生率,其中,坡位与松褐天牛深沟茧蜂呈显著正相关,其它天敌寄生率与松褐天牛深沟茧蜂寄生率呈显著负相关。[结论]以上研究初步明确了松褐天牛深沟茧蜂的寄生率与寄主树木、寄主害虫和天敌之间的关系,为今后利用该重要天敌控制松褐天牛打下了基础。     

松褐天牛的蛀道结构系统研究

[目的]通过系统解析松褐天牛在黑松和赤松内的蛀道结构,了解其蛀食特征,为完善松褐天牛隐蔽生活过程中的生物生态学习性和科学利用天敌昆虫、病原微生物和注射药物防治松褐天牛提供依据.[方法]于松褐天牛越冬期,人工解剖了松褐天牛危害的黑松和赤松木段,获得其完整蛀道.分别测量了蛀道长度、蛀屑堵塞长度、侵入孔内径、蛹室内径、?蛀屑...     

我国松墨天牛生物防治研究进展

松墨天牛携带松材线虫所引起的松树萎蔫已成为我国南方松林最严重的森林病害。利用生物防治方法防治松墨天牛已经成为关键措施。本文从病原微生物的利用和天敌的利用两方面综述了我国近年来松墨天牛防治工作取得的成绩,并针对松墨天牛的防治方面提出建议。     

花绒寄甲在北方防控松材线虫病效果分析

为实现长期的、可持续地控制松材线虫病的传播危害,就必须从生态学的角度出发,采用以生物防治为主,结合营林等综合治理的措施,在确保不污染环境的前提下,有效控制松褐天牛切断松材线虫病的传播途径,从而有效地控制松材线虫病的蔓延与发生。中国林业科学院首席专家杨忠岐教授的研究团队,长期致力于研究、示范和推广,利用天敌昆虫综合防治林业害虫,在我国的生物防治领域具有一定的影响。他们近几年又对松材线虫病的发生区,利用松褐天牛的重要寄生性天敌昆虫花绒寄甲对其防治进行研究,并且取得了明显的防治效果。为此我们荣成市林业局与中国林业科学院、北京农业职业学院进行项目技术合作,制定了《以生物防治为主防治松材线虫病传播媒介-松褐天牛的实施方案》,研究天敌昆虫花绒寄甲在荣成市对松褐天牛种群数量的控制效果。     

松汁中检出的捕食线虫的真菌

<正> Ⅰ.序言日本对松树枯萎病有一些防治方法。该病系松材线虫Bursaphelenchus Lignicolus及日本松天牛Monochamus alternatus所致。据信,利用天敌消灭松材线虫,防止松树枯萎病的发生是个可行的方法。当在研究线虫对松汁是否显趋化性时,偶然发现了捕食线虫的真菌。该真菌Arthrodotrys sp.在琼脂培养基上对松材线虫有捕食性,是线虫天敌的候选者。这与Mamiya和Tamura二人在日本松天牛蛹室中发现的Dactylella Ieptospora相似。     

松材线虫的天敌

松材线虫病是松树的毁灭性病害,已在我国南方5省发生蔓延,带来巨大损失。松材线虫病病原是松材线虫Bursaphelenchusxy-lophilus,媒介昆虫是松褐天牛Monochamusal-ternatus。有关松褐天牛的天敌研究和利用有大量报道,松材线虫的天敌研究尚未引起重视。作者在研究工作中发现...     

松墨天牛的天敌昆虫及其在生物防治中应用

系统介绍了松墨天牛的捕食性和寄生性天敌昆虫的种类、组成及其生防利用情况,重点阐述了管氏肿腿蜂、川硬皮肿腿蜂和花绒寄甲及几种具有开发应用潜力的天敌对松墨天牛的控制作用、利用途径及技术,并对今后天敌昆虫的研究和利用提出了几点建议。     

松褐天牛在马尾松树干上的分布规律

作为松材线虫病(Bursaphelenchus xylophilus)的最重要传播媒介,松褐天牛已成为控制松材线虫病的重点。明确松褐天牛各虫态在不同地区寄主树干上的分布,对因地适宜地释放天敌昆虫有着重要意义。为此,本研究通过解剖受害马尾松,结合林间调查,系统地研究了松褐天牛产卵刻槽、幼虫和蛹在马尾松树干上的分布规律。结果表明:松褐天牛产卵刻槽主要分布在树干的2.5 6.5 m范围内,刻槽数量与树干高度和胸径显著相关;松褐天牛幼虫数量与树干胸径关系不显著;多数蛹室位于侵入孔正上方,少数蛹室位于侵入孔下方,两种蛹室数量差异显著;两种蛹室与侵入孔中心的平均距离分别为3.93 cm和4.39 cm,两者之间差异不显著;并建立了松褐天牛幼虫在马尾松树干上的垂直分布模式图。本研究表明了松褐天牛种群密度与寄主树木大小的关系,为释放天敌进行生物防治提供了基础。     

释放天敌防治松褐天牛技术研究

林间开展了释放管氏肿腿蜂Sclerodermus guani Xiao et Wu和花绒寄甲Dastarcus helophoroides Fairmaire防治松褐天牛Monochamus alternatus Hope试验,结果表明:释放管氏肿腿蜂防治松褐天牛最佳益害比为4∶1,对松褐天牛寄生率达31.25%;释放花绒寄甲卵防治松褐天牛最佳益害比为8∶1,对松褐天牛寄生率达62.77%;释放花绒寄甲成虫最佳益害比为1∶1,对松褐天牛寄生率达70.69%。天敌释放区诱捕器诱捕到的松褐天牛成虫明显少于对照区。     

松褐天牛的初步观察

本文对江苏南部松材线虫病的主要媒介—松褐天牛的生活史、成虫羽化期、成虫寿命和产卵量、越冬后幼虫的死亡率和死亡原因等作了初步观察,经接种试验证实花绒坚(虫甲)是松褐天牛的天敌.     

释放天敌昆虫对松褐天牛的防治效果研究

在张家界国家森林公园、慈利县、韶山市、南岳区释放川硬皮肿腿蜂和花绒寄甲2种天敌昆虫,开展防治松褐天牛的试验。结果表明:2种天敌昆虫对松褐天牛有良好的控制作用,4个试验区的平均虫口减退率为92.65%,校正虫口减退率为91.41%;混合释放2种天敌昆虫的寄生率为92.42%,高于单独释放川硬皮肿腿蜂和花绒寄甲的寄生率62.00%和87.34%。     

卵巢线虫(Contortylenchus genitalicola)在中国松褐天牛上的分布与作用研究

[目的]日本学者Kosaka与Ogura发现松褐天牛成虫除携带松材线虫外,雌成虫卵巢内还携带有另一种线虫,他们将其命名为卵巢线虫,并认为这种线虫是松褐天牛成虫的寄生性线虫。我国对该种线虫的研究迄今未见报道。为了证明这种线虫在我国是否存在和分布,开展了本项研究。[方法]分期分批捕获刚羽化的松褐天牛雌雄成虫,采用解剖松褐天牛成虫松树木质部及感病的松褐天牛幼虫等方法,调查卵巢线虫的存在与分布。[结果]通过调查研究,发现我国的松褐天牛成虫体内有该卵巢线虫存在,分布于松褐天牛成虫、幼虫体内和松树木质部3个部位;在松褐天牛成虫体内的卵巢线虫通过松褐天牛雌成虫产卵而接种、进入寄主树木木质部中。同时,木质部的卵巢线虫也有一部分进入松褐天牛幼虫体内寄生,另一部分仍在木质部生活,当松褐天牛幼虫再次发育为成虫时,在木质部中的卵巢线虫和已被寄生的松褐天牛幼虫体内的卵巢线虫再次进入松褐天牛成虫体内,完成循环。卵巢线虫在松褐天牛雌、雄虫体内均有分布,携带率为44.4%,其中松褐天牛雌成虫携带率为43.8%,松褐天牛雄成虫携带率为45.0%,两者间无显著差异;每头松褐天牛成虫平均携带卵巢线虫574条,其中雌成虫平均携带816条,雄成虫平均携带308条,具显著差异。初步研究表明,卵巢线虫在松褐天牛成虫体内只能完成产卵到1~4龄的幼虫阶段,不能完成一个完整的世代;在松褐天牛幼虫体内寄生和在木质部生活的卵巢线虫能完成一个完整世代,但具体过程尚不清楚;调查中未观察到卵巢线虫对松褐天牛成虫有寄生致病或致死的现象,但对松褐天牛幼虫有寄生致死的能力;卵巢线虫常与松材线虫同时存在,而且侵入松树及离开松树的方式与松材线虫相同。[结论]我国松褐天牛体内也发现有卵巢线虫存在;目前尚不能证明该线虫对松褐天牛成虫具有寄生致死性,但对松褐天牛幼虫具有一定的寄生致死性;卵巢线虫的生活史与松材线虫相似,是否与松材线虫一样对松树具有危害性以及其病理作用还有待于进一步研究。     

Role of asymptomatic carrier trees in epidemic spread of pine wilt disease

To determine why pine wilt disease caused by the pinewood nematode (Bursaphelenchus xylophilus) recurs in the same pine stand even after thorough eradication of dead pine trees, the amount of oleoresin exudation from artificial wounds was measured from 72 Pinus koraiensis trees, highly susceptible to this disease, for 4 years. The amount of exuded oleoresin was rated from 0 to 4. All values obtained for each tree were summed at each measurement; thereby a cumulative curve was drawn to monitor the physiological condition of each test tree. Cumulative curves suggest that some pine trees that died had already been infected in the previous year or earlier and then had survived without any visible symptoms. If cessation of oleoresin exudation delays, and overlaps with activity of Monochamus alternatus, the vector beetle of pinewood nematodes, in the following season, such trees can be referred to as latent carriers or asymptomatic carriers. They could play a significant role as attractants for M. alternatus that could then transmit B. xylophilus to neighboring trees. Behavior of M. alternatus caged with several pine seedlings, only one of which acted as an asymptomatic carrier of B. xylophilus, confirmed this idea. The presence of asymptomatic pine trees, which harbored B. xylophilus nematodes or had reduced annual elongation, near stumps of newly dead trees in the study stand also substantiated this hypothesis.     

Insect vectors of the pinewood nematode: a review of the biology and ecology of Monochamus species

Pine wilt disease (PWD), caused by the pinewood nematode (PWN), Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle 1970 , is a serious threat to susceptible pine forests of the world. The PWN is primarily vectored by Monochamus species (Coleoptera: Cerambycidae). The first occurrence of PWD was reported from Japan in the early 1900s. Following this report, Japanese scientists documented the community of bark‐ and phloem‐inhabiting insects associated with the nematodes in dying trees to determine possible vectors of the nematode. Monochamus alternatus was reported to be the most effective vector in Japan. The primary vector in North America is Monochamus carolinensis, and in Europe, it is Monochamus galloprovincialis. Further studies have been expanded through the nematode‐invaded countries of Korea, Taiwan, China and Portugal. There is an interspecific association between the PWN and its insect vectors, and it is an obligatory component of the disease cycle. It is crucial to understand this relationship as well as the population ecology of the beetle to aid in monitoring and control of this worldwide threat to pine forests. Studies to date indicate a remarkable similarity among beetle species around the globe for a variety of life‐history traits, including lifespan, adult emergence numbers, flight capability, nematode transmission rates and attraction to pine volatiles. Wherever pines are found, there is a beetle species capable of transmitting the nematode. Although flight performance and range is generally poor for this group of beetle vectors, the cryptic nature of the species and the lack of interest in the beetles by countries in the absence of the nematode have led to the disease establishing a foothold in a variety of countries such as Portugal. In this paper, studies conducted in different countries on Monochamus vector species of the PWN are compared and discussed.     

Abundance-dependent transmission of the pinewood nematode, <Emphasis Type="Italic">Bursaphelenchus xylophilus</Emphasis> (Nematoda: Aphelenchoididae), to the Japanese pine sawyer, <Emphasis Type="Italic">Monochamus alternatus</Emphasis> (Coleoptera: Cerambycidae), adult in its pupal chamber

The transmission ratio of the pinewood nematode (PWN), Bursaphelenchus xylophilus, to the emerging adult Japanese pine sawyer (JPS), Monochamus alternatus, in its pupal chamber is a determinant of the number of the nematodes carried by JPS beetles. To investigate the factors affecting the transmission ratio, we counted the number of the nematodes carried by 36 newly emerged JPS beetles and the number remaining in and around their pupal chambers, and then estimated the transmission ratio (the number of nematodes carried by a JPS adult as a percentage of the total number of nematodes aggregating in and around its pupal chamber). The total number of nematodes aggregating in and around a pupal chamber ranged from 0 to 19,041, and the number of nematodes carried by a beetle ranged from 0 to 18,920. The transmission ratio correlated with neither the water content of the wood around the pupal chamber nor the degree of wood discoloration caused by blue-stain fungus. The transmission ratio varied with the abundance of the nematodes aggregating in and around the pupal chamber. In pupal chambers with more than 1,000 nematodes, almost all the nematodes were transmitted to the beetle. However, in pupal chambers with fewer than 1,000 nematodes, the transmission ratio varied greatly, from 0 to 100%. These results suggest that aggregation of many PWNs in the pupal chamber might stimulate transmission of the PWNs to the JPS adult and that this abundance-related transmission might contribute to the large variation in the number of PWNs carried by the JPS beetle.     

Predatory behavior of Tetrigus lewisi on Monochamus alternatus

Pine wilt is a serious and fatal disease in pine forests. It is caused by the pine wood nematode, Bursaphelenchus xylophilus, transmitted by the Japanese saw beetle Monochamus alternatus. Control of this disease depends on reducing its vector population. The public is demanding environmentally friendly control methods and biological control has become increasingly seen as an impor-tant, safe and effective approach. Through our investigations both in the field and by breeding in our laboratory, a new predator of M. alternatus, Tetrigus lewisi （Coleoptera： Elateridae）, was found for the first time in China. Given our continuous observations, we are assured that the predatory behavior of the elater can be separated into four parts, i.e., foraging and sensing, killing, eating and excre-tion. They always took several hours to eat the preys that have been killed momentarily. We finally found that most of the elaters preferably attacked in the stomach and abdomen of the larva of M. alternatus.     

噻虫啉飞机喷雾防治松褐天牛现状与应用展望

松褐天牛是促使松材线虫病广泛传播的主要媒介,如何压低林间种群是当前防控的主要挑战之一。近年来,林区飞机喷雾防治（飞防）松褐天牛兴起,覆盖我国12个省份27个市,以喷施噻虫啉为主。飞防速度快、覆盖面大,较常规方法优势明显。然而,噻虫啉飞防效果与风险仍备受关注。文中简要回顾国内外林区飞防发展历程;基于前期噻虫啉药效、残留实验结果,结合飞防自身问题与我国噻虫啉飞防现状,及松褐天牛与美国白蛾等林业害虫飞防案例对比,综述噻虫啉飞防松褐天牛所面临的挑战与问题,提出后续研究中需结合林区飞防实际,在剂型选用、种群长期压制、生物多样性风险等方面深入研究,以出台专门技术规程,促使噻虫啉飞防技术改进,实现科学飞防。