松材线虫病发病过程特征变化的研究

为提高松树病死木松材线虫检出率,及时、准确诊断疫木和疫点,根据病害的外部症状,把松材线虫病的发病过程分为四个阶段,对各阶段的松材线虫分布、松褐天牛发生情况、含水率的变化、木材蓝变情况等特征进行研究。结果表明：病死木上松材线虫的分布由多到少为：在发病前期,上部〉中部〉下部;发病后期,上部〈中部〈下部。松材线虫的数量与松褐天牛老熟幼虫的数量呈正相关,最佳的取样阶段为第Ⅱ和第Ⅲ阶段靠上部梢段取样,第Ⅳ阶段偏下部取样。     

松材线虫病治理区病原数量的调查研究

对松材线虫病治理区室内、林内松褐天牛羽化期携带松材线虫以及诱木中松材线虫的情况进行调查,结果表明在室内、林内松褐天牛携带松材线虫的几率分别为25．5％、22．0％;松褐天牛成虫携带松材线虫量均以6月份最大,平均625条／头、478条／头;诱木中松褐天牛携带松材线虫数量与其寄生的枯死诱木含松材线虫数量呈正相关,5％水平上成极显著相关,相关系数为0．933。     

松材线虫病的细菌参与学说

<正>松材线虫病是由松褐天牛为媒介者携带病原体松材线虫而引起的一种松树的传染病。因此,其防治对策应基于松树、松材线虫、松褐天牛三者之间的相互关系。     

松材线虫在病木和天牛中分布特征分析

对病木的松褐天牛蛹室木屑、蛹室边缘木材、离蛹室5cm远木材以及松褐天牛进行线虫数量的镜检和分析，其线虫数量经方差分析差异不显著，而不同蛹室及其附近不同木材线虫分布的总量差异极显著。从松褐天牛上分离出的线虫数量差异相当大，从0-66.31条/cm^2不等。死的松褐天牛没有分离出松材线虫，活的松褐天牛经分离后也存在不携带松材线虫现象，而能够分离出线虫的雄雌天牛之间没有呈现一定的变化规律。     

昆明市海口林场松材线虫病调查报告

通过试验统计了海口林场内部松褐天牛携带线虫的几率,以及携带线虫中是否含有松材线虫等参数,并据此编制了海口林场松材线虫病调查报告,采用对照试验的方法,分别从室内获取松褐天牛134只,以及从林内使用诱捕器获取松褐天牛114只,分别测量了两组松褐天牛中携带线虫的数量及占比,以及这些松褐天牛中每只身上携带各类线虫的数量。根据试验获得的参数,对差异产生的原因进行了分析。结果表明:松褐天牛中有一部分携带线虫,但是以其他线虫和拟松材线虫为主,并未发现松材线虫,由此可得知海口林场内没有松材线虫病。并可以为下一步松材线虫病的防控提供科学依据。     

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。     

松材线虫病防治试验初报

在南京地区连续二年对松材线虫Bursaphelenchus xylophilus Nickle病的媒介昆虫松褐天牛Monochamus alternatus Hope成虫羽化、成化率以及在松树上的分布和发生情况等观察,结果表明:5月下旬至6月上旬为松褐天牛的羽化盛期,且70%天牛寄生在松树5m以上的树干和枝梢中;防治上要注重病死树枝梢材的处理,MPP乳剂的防治区松材线虫病死树明显减少,喷MPP油剂处理病材对天牛毒杀作用较好。     

松材线虫与其伴生细菌在寄主内的种群动态

利用马尾松水培离体松枝作接种材料 ,分别接种消毒后的松材线虫、松材线虫伴生细菌坚强芽孢杆菌和松材线虫与坚强芽孢杆菌的混合液 ,以研究松材线虫与其伴生细菌在松枝中的种群动态。结果表明 :松材线虫和坚强芽孢杆菌混合接种 ,松枝发病 ,松枝髓部发生褐变 ,褐变的过程是由接种枝发展到主枝 ,再由主枝下部向上部发展 ,而单独接种松材线虫或坚强芽孢杆菌 ,松枝不发病 ;松材线虫和坚强芽孢杆菌混合接种较单独接种松材线虫 ,松枝中的松材线虫繁殖量大、扩散速度快 ;松材线虫在松枝中扩散的过程是 :接种枝→主枝→侧枝→新梢 ,在主枝中由下部向上部扩散 ;松枝髓部褐变过程和松材线虫在松枝中扩散过程相一致 ,松材线虫扩散分布先行于髓部褐变 ;松材线虫和坚强芽孢杆菌混合接种较单独接种松材线虫或坚强芽孢杆菌初期 ,松枝中致病细菌的检测量大 ,从而提出细菌和松材线虫均是松材线虫病不可缺少的致病因素。文后指出寄主主干下部髓部褐变可用作病害的早期诊断。     

松材线虫在罹病木中种群动态的初步研究

本文对松材线虫的种群动态特别是感病树枯死以后的种群动态进行了初步研究。枯死初期树干上部种群数量高于中、下部,枯死一段时间后树干下部种群数量高于中、上部;在同一部位内材线虫数量高于外材;化蛹期间89.3%—96.7%的线虫聚集在蛹室周围;羽化期间蛹室周围线虫的66.7%—84.2%被羽化出孔的松褐天牛成虫携带,携带率100%。     

黄山风景区松材线虫病危险性评估 Ⅱ.松天牛携带线虫状况的监测

报道了黄山风景区松墨天牛、褐幽天牛和短角幽天牛3种主要松蛀虫成虫携带拟松材线虫等非病原线虫的情况.监测显示3种松蛀虫均能携带线虫,以松墨天牛携带机率最高,达61.3%.褐幽天牛和松墨天牛平均携带线虫数量较多,分别为5 128.6、3 622.0条·头-1.温泉的松墨天牛和西海的褐幽天牛携带的线虫数量最高,分别达4 781、10 840条·头-1.本文还报道了不同时间诱捕的松墨天牛和褐幽天牛性别、个体大小与携带线虫数量的关系.     

松墨天牛成虫羽化逸出及其携带松材线虫能力的研究

松墨天牛成虫是松材线虫病的主要传播媒介,研究其成虫羽化逸出规律及其携带松材线虫能力,在松墨天牛和松材线虫的监测和综合治理上具有重要意义。研究结果表明,松墨天牛成虫羽化逸出期和高峰期,平均每年分别为８３ｄ和１２．３ｄ。携带松材线虫的松墨天牛成虫平均寿命为２９．８ｄ。松墨天牛成虫全身均能携带松材线虫,其数量比率顺序为胸〉头〉腹〉触角〉足〉翅。在浙江省富阳市,林间采用引诱剂诱获的松墨天牛成虫,平均每头携     

松材线虫病的诊断方法探讨

控制松材线虫病的关键是及时诊断疑似疫木、疫点,既能采用有效、简单、易行的方法进行诊断,且能有的放矢地进行诊断。文章根据广东省松材线虫病疫区的特点,对林间枯死松树外观症状诊断法、林间枯死松树体内线虫的分离鉴定法和松褐天牛引诱剂辅助诊断法等3种松材线虫病的诊断方法及其适应范固进行探讨。     

老疫区松材线虫病持续控制技术研究

2005～2009年在广州市松材线虫病老疫区系统开展了疑似病死松树的早期诊断、应用引诱剂和林间释放花绒寄甲控制松褐天牛、清理病死木套袋熏蒸和疫区松林植物群落结构改造等持续控制技术研究.结果表明:疫区内松树枯死木松材线虫的检出率为22.1%～55.4%.诱到松褐天牛成虫19 853头,每个诱捕器的诱虫量为14.06～24...     

上虞市松材线虫病综合防治与思考

上虞市自2004年发生松材线虫病以来积极采取各种防治措施,包括枯死松树全面清理下山,疫木经热处理生产工艺进行除害处理和安全利用,实施松材线虫病除治林相改造工程,挂诱捕器、设饵木消杀松墨天牛等。几年下来除治效果显现,松材线虫病已得到有效控制。     

Pine bark beetle problem in Japan,referring to the discovery of the pine wood nematode,Bursaphelenchus lignicolus (Mamiya & Kiyohara)

Heavy loss of pine trees has been occurring for several decades throughout central to southwestern districts of Japan. In spite of beetles abundantly found under bark of dead trees, entomologists were inclined to the assumption that some other agents had already infected healthy trees before beetle attack based on various findings. It has been proved recently that the causative agent was the pine wood nematode (Bursaphelenchus lignicolus) newly discovered by pathologists and its transmitter was the Japanese pine sawyer (Monochamus alternatus). Aerial application of insecticides against the sawyer is now employed as a tentative measure of control.     

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。     

First record of Ektaphelenchoides pini associated with Ips sexdentatus on Pinus nigra laricio in Italy

In February 2015, an unexpected windstorm downed five hectares of a European black pine Pinus nigra subsp. laricio forest formation located close to Vallombrosa, Florence (Central Italy). In the following spring, an extensive survey was conducted in the area. Felled trees, stumps and all the suitable plant material were screened for the presence of the pinewood nematode (PWN), Bursaphelenchus xylophilus, by sampling wood and bark. Bark beetles were then collected from the gallery systems on the inner side of bark samples and observed in the laboratory. The following bark beetles were morphologically identified: Ips sexdentatus, Orthotomicus erosus, O. laricis and Pityogenes bidentatusa. The dissection of Ips sexdentatus allowed the extraction of numerous nematodes that were morphologically and molecularly identified as Ektaphelenchoides pini. Conversely, only few nematode specimens were isolated from either pine bark or wood. These individuals could be only molecularly identified and belonged to an undescribed nematode taxon. Even though no PWN was recorded in the investigated sites, our survey allowed the detection of a new association between E. pini and I. sexdentatus on P. nigra.     

Promotion of the population growth of pinewood nematode in 4-month-old Japanese black pine seedlings by pretreatment with simulated acid rain

Simulated acid rain (SAR) at three pH levels (pH 4, 3, 2) was applied to only the top or both the top and roots of 4-month-old Japanese black pine seedlings repeatedly for two months. Then the seedlings were inoculated with a virulent isolate (S10) of pinewood nematode,Bursaphelenchus xylophilus. The exposure to SAR at any level did not kill the seedlings. When inoculated with nematodes, however, the nematode population build-up was significantly higher in the seedlings pretreated with SAR at any level than in the control at the 7th and 17th day after inoculation, and subsequent disease symptom development was also significantly accelerated by the exposure to SAR at pH 2 and 3. This result indicates that even acid rain at pH 4 has the potential for promoting population growth of pinewood nematodes in 4-month-old Japanese black pine seedlings.     

Possible altitude and temperature limits on pine wilt disease: the reproduction of vector sawyer beetles (Monochamus alternatus), survival of causal nematode (Bursaphelenchus xylophilus), and occurrence of damage caused by the disease

Pine wilt disease is caused by the pine wood nematode [Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle]. In East Asia, an important vector of the nematode is Monochamus alternatus Hope. We determined the tolerance and reproductive ability of sawyer beetles and the nematode to altitude and temperature at elevations between 850 and 1,450 m on Mt. Fuji in Japan. The number of emergent adults decreased markedly along the altitudinal gradient, but the beetle could still reproduce at 1,050 m (8.2 °C annual mean temperature). Beetles with a 2-year life cycle increased rapidly in number with increasing altitude. The pine wood nematode survived through winter at all altitudes tested (850–1,450 m). The beetle population decreased between 950 (9.1 °C) and 1,150 m (8.3 °C). Therefore, the beetle population seems to be stable at 850 m (10.2 °C) and lower altitudes (higher temperatures) but cannot be maintained from 950 (9.1 °C) to 1,150 m (8.3 °C) without constant immigration of beetles from lower altitudes. The beetles could not reproduce at altitudes above 1,150 m (lower than 8.2 °C). From the mean and effective cumulative temperatures, we concluded that the beetle (and its population) can endure temperatures lower than those previously reported. Pine wilt disease also occurred at lower temperatures and higher altitudes than expected. We have summarized the principal strategies for controlling the disease at high altitudes based on these results.