Emamectin benzoate 9.7% SL as a new formulation for a trunkinjections against pine wood nematode,Bursaphelenchus xylophilus

In this study,we investigated the preventive effects of emamectin benzoate 9.7% SL,which was newly developed to reduce the injection volume and number of injection holes required to protect against pine wood nematode.None of the Pinus thunbergii trees injected with emamectin benzoate 9.7% SL at 0.3 mL/cm diameter at breast height(DBH) died within 2 years of inoculation with pine wood nematodes.Emamectin benzoate 9.7% SL injected at 0.6 mL/cm DBH resulted in no tree mortality for 3 years.Mean residue of emamectin benzoate 9.7% SL in pine twigs injected with 0.3 mL/cm DBH was 0.490 μg/g at 1 year after injection and 0.303 μg/g after 2 years.These residues values are greater than 0.031 μg/g,previously determined IC95 value for emamectin benzoate against the pine wood nematode.Our field experiment and residue analysis showed that emamectin benzoate 9.7% SL could be a substitute agent for emamectin benzoate 2.15% EC,which is widely used to prevent pine wood nematode in the field and that injection volume and number of injection holes can be greatly educed using this new formulation,which will reduce injury to the cambium,interruption of water movement,and infection of inoculation wounds by wood-decay or blue stain fungi.     

The pine wood nematode Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle (=B. lignicolus Mamiya and Kiyohara): an assessment of the current position

Pine wood nematode, Bursaphelenchus xylophilus (Steiner andBuhrer) Nickle, is the casual organism of pine wilt disease,a major tree killer in the Far East. This paper describes thebiology of B. xylophilus, particularly its inter-relationshipswith vector insects in the genus Monochamus (Coleoptera: Cerambycidae),tree species and environmental conditions. The principal methodof transmission, and hence of international plant health significance,is introduction of nematodes to susceptible dying or dead treesduring female oviposition. This occurs in all countries wherethe nematode occurs but is the only significant method of transmissionand survival of B. xylophilus in North America. Extensive treemortality in Japan and China is associated with presence ofhighly susceptible tree species, suitable vector species andhigh summer temperatures. Pest risk assessments have been carriedout to determine the risks to Europe; it is concluded that thenematode would undoubtedly survive in Europe but that tree mortalityis likely only in the warmer southern countries. Methods toprevent transfer of nematodes to Europe are discussed in relationto European Union legislation.     

Lethal temperature for pinewood nematode, Bursaphelenchus xylophilus, in infested wood using radio frequency (RF) energy

We evaluated radio frequency (RF) dielectric heating for eradication of pinewood nematodes (PWN) in infested wood. Thirteen temperatures were tested (from ambient to 70 °C) on small wood samples (2.5 × 3.8 × 0.64 cm) to determine the minimum lethal temperature (100 % mortality), which was 56 °C [based on infra-red (IR) thermal images data 55.5–57.4 °C] with a 1 min hold time. We also used thermal probes inside the wood to confirm that temperatures were ≥56 °C. Thirty additional samples were tested bracketing the minimum lethal temperature using 54, 56 and 58 °C with additional replications to produce the minimum sample size equivalent of 100 % mortality of at least 93,616 nematodes to satisfy the Probit 9 efficacy requirement. This minimum lethal temperature was further verified by treating infested large wood blocks (10.2 × 10.2 × 25.4 cm). All samples that met or exceeded the 56 °C lethal temperature for the required 1 min hold time (as measured by probes inserted in the wood and on the wood surface by IR) produced 100 % mortality. The sample size required to show Probit 9 efficacy was also satisfied. This study supports the consideration of RF in addition to microwave (MW) dielectric heating as alternative treatments of wood packaging material for inclusion in ISPM No. 15, provided the treatment delivers the target lethal temperature throughout the profile of the material in industrial scale operations.     

Canadian conifers as hosts of the pinewood nematode (Bursaphelenchus xylophilus): Results of seedling inoculations

Seedlings of 22 species of conifers from across Canada were inoculated with m and r form isolates of the pinewood nematode (Bursaphelenchus xylophilus). In an experiment made under ambient (summer‐fall) temperatures in a shadehouse at Victoria, British Columbia, Canada, 8 of the 22 conifer species were killed by the nematodes, but mortality was low, i.e. 4–30%. Pines (eastern white, Jack and red) were more susceptible than other conifers. Yellow cypress, eastern white cedar, western red cedar and western hemlock were not killed by the nematodes. In a second experiment made at elevated temperatures (30°C‐16h long days, 25°C‐8 h long nights) in a greenhouse, 18 of the 22 conifer species died following nematode inoculation. Again, pines (lodgepole, eastern white, western white and red) were among the most susceptible tree species and the four conifers that were unaffected in the first experiment were not killed. Tamarack and western larch, both immune at ambient temperatures, were the two most susceptible conifers at elevated temperatures. Compared to ambient temperatures, seedlings at elevated temperatures died quicker and contained more nematodes. M and r form nematodes were equally pathogenic in both experiments.     

松材线虫病与松墨天牛研究概况

松材线虫病Ｂｕｒｓａｓｐｈｅｌｅｎｃｈｕｓｘｙｌｏｐｈｉｌｕｓ是松树的毁灭性病害。最早由美国的Ｓｔｅｉｎｅｒ ,Ｑ等在路易斯安那州的沼泽松Ｐｉｎｕｓｐａｌｕｓｔｒｉｓ的木材中发现 ,后由Ｎｉｃｋｌｅ,Ｗ .Ｒ定名。但美国的研究工作开展较晚 ,是从 1979年在密苏里州发现由松材线虫造成松树萎焉后才开始研究的 (彭趋贤 1990 )。现在已有 33个州发生。世界上研究最早的是日本。矢野 190 5年首先在长崎市周围的松林中发现松树萎焉 ,之后进行了调查研究 ,1913年作了报道 ,虽然当时未能明确是松材线虫病 ,但所记述的症状实际上就是现在…     

Response of pine forest to disturbance of pine wood nematode with interpretative structural model

Pine wood nematode (PWN, Bursaphelenchus xylophilus), originating from North America, causes destructive pine wilt disease. Different pine forest ecosystems have different resistances to B. xylophilus, and after its invasion, the resilience and restoration direction of different ecosystems also varies. In this study, an interpretative structural model was applied for analyzing the response of pine forest ecosystem to PWN disturbance. The result showed that a five-degree multi-stage hierarchical system affected the response of the pine forest ecosystem to PWN disturbance, in which direct affecting factors are resistance and resilience. Furthermore, the analysis to the 2nd, 3rd and 4th degree factors showed that not only does distribution pattern of plant species and pine’s ecological features affect the resistance of pine forests’ ecosystem, but removal of attacked trees and other measures also influence the resistance through indirectly affecting the damage degree of Monochamus alternatus and distribution pattern of plant species. As for resilience, it is influenced directly by soil factors, hydrology, surrounding species provenance and biological characteristics of the second and jointly dominant species, and the climate factors can also have a direct or indirect effect on it by affecting the above factors. Among the fifth elements, the elevation, gradient and slope direction, topographical factors, diversity of geographical location and improvement of prevention technology all influence the response of pine forest ecosystem to PWN disturbance. __________ Translated from Scientia Silvae Sinicae, 2007, 43(8): 85–90 [译自: 林业科学]     

加工活性炭处理松材线虫病死木技术的研究

经３ａ的试验和实践结果表明,加工活性炭处理松材线虫病死木中松褐天牛成、幼虫等媒介昆虫是一项简单易行、灭害彻底、效益较高的处理松材线虫病死木的新技术,值得在疫区推广应用。     

树干注药技术预防松材线虫病的效果评价

松材线虫病是松林的毁灭性病害,过去几十年已在日本、韩国及中国等东亚国家迅速传播扩散.加强对非疫区的监测与保护是目前关注的重点,利用1％阿维菌素微囊悬浮剂对马尾松进行树干注药以预防松材线虫病,研究结果表明,树干注药处理区的枯死松树要显著少于不实施注干的对照区,且处理区内枯死松树比率不超过2％.因此,通过树干注药技术施用1％阿维菌素微囊悬浮剂对预防松材线虫病能起到显著效果.     

Basic density,extractive content and moisture sorption properties of Pinus pinaster wood infected with the pinewood nematode,Bursaphelenchus xylophilus

The pinewood nematode(PWN), Bursaphelenchus xylophilus, has become one of the most severe threats to pine forest worldwide. Nematodes, migrating through resin canals and feeding on the living cells, induce rapid metabolic changes in ray parenchyma cells, create cavitation areas, decrease xylem water content and oleoresin exudation, and cause necrosis of parenchyma and cambial cells. This study focused on the impact of PWN infection on technological parameters of wood and evaluated the impact of anatomic and biochemical incidences of tree defense reactions on basic density, extractive content and moisture sorption properties of Pinus pinaster wood.Samples of infected and uninfected wood were studied.The presence of nematodes reduced wood basic density by2 % and decreased the total content of extractives in infected wood as compared with uninfected(5.98 and8.90 % of dry wood mass, respectively). Extractives in infected trees had inverse distribution along the trunk as compared with uninfected trees. The adsorption isotherms for infected and uninfected wood had similar positioning.We recorded differences(some statistically significant) in the equilibrium moisture content of infected and uninfected wood under varying environmental conditions. Despite the verified differences in wood basic density, extractive content and moisture sorption properties, the overall conclusion is that the PWN had a slight impact on these characteristics of wood.     

松材线虫病县级预防监测体系模式建设探讨

通过对桃源县5年来松材线虫病预防监测体系模式建设的不断完善和总结,认为县级松材线虫病“县、乡、村三级”预防监测体系的建成,具有见效快、投资少、操作方便等优点。该体系一旦启动,可以收到良好效果。     

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.     

松材线虫病被害木伐桩灭虫试验研究

通过林间调查、根桩解剖、线虫分离等试验,结果表明,在伐桩、木质部内存在数量较少的松褐天牛越冬幼虫;该幼虫次年羽化成成虫,具有传播松材线虫病能力。通过对不同高度伐桩中天牛活体数量调查和农药处理伐桩试验,认为在伐桩高度低于５ｃｍ时,用２０％倍硫磷油剂＋０号柴油２０倍稀释液浇淋伐桩,具有既简单又彻底的杀灭伐桩内天牛和控制松材线虫病的良好效果。     

汕头市松材线虫病的防治

基于汕头市濠江区已发现松材线虫病疫情的实际情况,针对该病的防治特点,结合汕头市各辖区山林的实际情况,从判断、预防、治理三个方面提出相应的防治对策,为科学防控该病在我市的扩散危害提供参考。     

Pathogenicity of canadian isolates of the Bursaphelenchus xylophilus (pinewood nematode) to provenances of Pinus sylvestris and Pinus contorta as grown in Finland: A greenhouse study

Seedlings of Scots pine (Pinus sylvestris L.) and lodgepole pine (P. contorta Dougl.) provenances, as grown in Finland, were inoculated with “m”; and “r”; “forms”; of the pinewood nematode (Bursaphelenchus xylophilus) from Canada, an m form isolate from France and an r form isolate from Missouri, USA. Scots pine was highly susceptible to an Alberta r form and a British Columbia m form isolate and moderately susceptible to two Quebec m form isolates. Lodgepole pine was higly susceptible to the two r form (Alberta and Missouri) isolates and moderately susceptible to the British Columbia m form and the two Quebec m form isolates. Mortality of both pines after inoculation with the French isolate was inconsistent. Mortality of both pines occurred more rapidly following inoculation with r form than with m form nematodes. Large numbers of nematodes were generally found in the tissues of both pines. Our results with seedlings need to be corroborated by inoculating larger field‐grown trees.     

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.     

木腐菌对松材线虫病病死树伐桩的作用

采用硫磺菌菌株6600、杂色云芝菌株6923、松生拟层孔菌菌株W11、茯苓菌株6284和粗皮侧耳菌株6221接种处理松材线虫病病死树伐桩,研究5个菌株对伐桩的分解能力以及对伐桩内松材线虫的作用情况.结果表明:硫磺菌菌株6600对伐桩的分解能力以及对伐桩内松材线虫的抑杀作用都最强;对伐桩内松材线虫数量与伐桩样品质量的相关分析表明两者呈极显著的正相关.该研究为今后在实际生产中利用木腐菌处理伐桩奠定了重要的基础.     

安徽省松材线虫病的除治措施及成效

近两年 ,经过不懈努力 ,安徽省松材线虫病发生面积、病死树数量、疫情发生点个数呈现了连续下降的良好态势。为此 ,总结了部分松材线虫病治理区在几个除治环节 (监测、清理、伐桩处理 )上的成功做法 ,供其他松材线虫病治理区参考。     

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。     

Patterns of biomass,carbon,and nitrogen storage distribution dynamics after the invasion of pine forests by Bursaphelenchus xylophilus (Nematoda: Aphelenchoididae) in the three Gorges Reservoir Region

Masson pine stands infected by Pine wilt disease(PWD) in the Three Gorges Reservoir Region of central China were surveyed to quantify the immediate responses and subsequent trajectories of biomass,carbon(C),and nitrogen(N) in stand-level major ecosystem compartments.The biomasses of above-and belowground tree components,as well as of the understory,forest floor,and mineral soil(0–40 cm),were determined within each stand.C and N storage were also estimated for each ecosystem compartment.Overstory biomass decreased steadily with the extent of PWD infection.Understory biomass ranged from1.97 to 4.16 Mg ha~(-1),and the observed value for forest floor biomass was 12.89–22.59 Mg ha~(-1).The highest mean C and N concentrations were found in the stem bark and needles of Masson pine,respectively,while the lowest were found in the semi-to fully decomposed layer of the forest floor and stem wood of Masson pine,respectively.The C and N storage of aboveground trees,tree roots,and the aboveground ecosystem decreased with the extent ofPWD infection.However,the C and N contents of the understory,forest floor,and total mineral soil initially declined after PWD infection before recovering over the following several years.Those result concluded that the biomass,C,and N storage of different forest ecosystem compartments have experienced certain variations following the PWD epidemic.This is vital to understand the shifts in stand-level C and N allocation in PWD-damaged forest stands,as well as for predicting the responses of regional and global C and N cycling.     

抗松材线虫病马尾松无性系种子园营建技术

松材线虫病是危害松属树种的毁灭性病害,危害严重、防治困难。安徽省从2001年开始从疫区和非疫区的马尾松林分中选择324株抗病优树以及部分广东、广西种源,通过嫁接繁殖和人工接种松材线虫的方法进行无性系抗病性测定。2011年利用筛选出的68个家系的89个高抗无性系营建了1.6 hm2抗松材线虫病马尾松无性系种子园。各家系成活率90.9%～100%,平均成活率93.6%。