云南松树伞滑刃线虫种类鉴定

 2000~2001年从云南省34个县/市调查采集到病松树样本161份,鉴定出伞滑刃属线虫3个种即拟松材线虫(Bursaphelenchus mucronatus)、霍夫曼伞滑刃线虫(B. hofmanni)和赫列尼库斯伞滑刃线虫(B. hellenicus)。后2种为我国新记录种,其寄主分别是华山松(Pinus armandii)和云南松(P. yunnanensis),为该2种线虫的世界新寄主记录。目前云南省没有发现松材线虫,但在16个县/市发现拟松材线虫。     

Report on the survey for Bursaphelenchus xylophilus and the occurrence of other Bursaphelenchus species in Hungarian coniferous forests

An ongoing official survey to detect the pine wood nematode Bursaphelenchus xylophilus, a quarantine pest, started in 2003 in coniferous forests in Hungary. Based on the results of the study from 2003–11, B. xylophilus has not yet been detected in Hungary. Two other Bursaphelenchus species (B. mucronatus and B. vallesianus) were identified in samples in 2009. Details of the survey and the measurements of B. mucronatus and B. vallesianus are provided.     

Occurrence and ITS diversity of wood‐associated Bursaphelenchus nematodes in Scots pine forests in Switzerland

The quarantine pathogen Bursaphelenchus xylophilus (pine wood nematode, PWN) represents a serious threat for Pinus species in Europe. To exclude its presence in Switzerland, in 2010 and 2011 a countrywide survey was conducted in 102 Pinus sylvestris stands, chosen according to whether they contained dying or dead trees or were located in areas at risk of PWN introduction. In total, 285 trees (1–5 per site) were sampled. Nematodes were extracted from wood chips using a standard procedure, and identified to species by internal transcribed spacer (ITS) sequencing. Bursaphelenchus species were present in 34% of the trees, but no B. xylophilus was identified, i.e. PWN is still not present in Switzerland. The nematodes found belonged to seven different species, with B. vallesianus the most frequent species, followed by B. sexdentati, B. mucronatus kolymensis and B. eggersi. Three other species (B. borealis, B. pinophilus, B. poligraphi) were each only present in one or two trees. Three groups of sequences could not be assigned to a species because of the lack of matching reference sequences. The species composition found in Switzerland suggests co‐existence of southern and central European Bursaphelenchus species. Intraspecific ITS variability differed considerably among the four most common species. Bursaphelenchus eggersi, B. mucronatus kolymensis and B. sexdentati had several variable sites in the ITS region, resulting in multiple ITS genotypes in each species. In contrast, all 99 B. vallesianus isolates had an identical ITS region. This could indicate a founder effect, and possibly that B. vallesianus is not native to the Alpine region.     

First record of Bursaphelenchus leoni in South Africa and comparison with some other Bursaphelenchus spp.

Bursaphelenchus leoni was found in wood of a severely wilted pine tree ( Pinus radiata ) in South Africa. Morphological studies and morphometric measurements showed the South African population to be conspecific with B. leoni which is widespread in southern Europe and indigenous in the Mediterranean region. In addition, molecular biological tests (RFLP analysis of amplified ribosomal DNA) confirmed this diagnosis and allowed comparisons with other Bursaphelenchus spp. from pine and other trees, i.e. B. xylophilus, B. mucronatus, B. fraudulentus and B. sexdentati. This is the first record of a Bursaphelenchus species in South Africa as well as in the southern hemisphere. P. radiata is recorded as a new host for B. leoni.     

2种常见伞滑刃线虫的特异PCR检测方法

包括松材线虫和椰子红环腐线虫在内的伞滑刃属线虫形态上相似性高,形态鉴定难度较大。本文通过对伞滑刃属常见线虫群体ITS2区序列比对、分析,设计了木质包装材料检疫中常见的泰国伞滑刃线虫和豆伞滑刃线虫特异引物对各1对,并研究了这2种常见伞滑刃线虫的PCR检测方法,使用本文特异引物可分别特异、快速检测出这两种线虫。     

Evaluation of a Swedish steam-dryer for treatment of Bursaphelenchus xylophilus in pine chips

A steam-dryer, designed and manufactured in Sweden, was evaluated for destroying Bursaphelenchus xylophilus in pine chips from southern USA. In a trial, pine chips were treated at different temperature and pressure regimes for 5 or 10min. The lowest time/temperature/pressure combination was to increase the vessel temperature from 85 to 104°C in 5 min at low pressure. Samples of pine chips were assayed for nematodes in laboratories in USA, Sweden, and Finland. No nematodes of any species were recovered from any of the treated pine-chip samples. Large and heterogeneous pieces of wood in the treated samples were also nematode-free. The apparatus was a prototype capable of handling about 400 kg h^-1. The final version would have to be able to process 100-200 th^-1.     

Preliminary survey for insects associated with Bursaphelenchus xylophilus in Portugal

The detection of Bursaphelenchus xylophilus in Pinus pinaster trees in Portugal in 1999 led the official services to implement exceptional and urgent control measures to prevent the spread of the pest. Because the pest is vector-transmitted, special attention was paid to the insects associated with infested trees. A survey comprising 21 species of insects, from six families, with a total of 1367 specimens, was made in order to evaluate their possible role as vectors of the nematode in Portugal. Five insect species were found to carry other Bursaphelenchus spp., but only Monochamus galloprovincialis was associated with B. xylophilus .     

松材线虫伴生细菌与松树萎蔫病关系的初步研究

利用马尾松水培离体松枝作接种材料,接种消毒后的松材线虫、线虫虫体上分离到细菌分离物GD1以及两者的混合体。结果表明,单独接种消毒后的松材线虫蔌细菌分离物GD1均不能使松枝萎蔫,只有两者混合接种才能使松枝发病枯死。从而说明了松材线虫的伴生细菌对松树萎蔫病的发生起着重要的作用。     

Potential for establishment of Bursaphelenchus xylophilus and the pine wilt disease under Nordic conditions1

Serious concern about the pinewood nematode, Bursaphelenchus xylophilus, and the pine wilt disease arose in 1984 when the nematode was discovered in wood chips imported for the Finnish pulp industry. It has been questioned whether this nematode could establish itself and actually damage pine trees under Nordic conditions. It seems likely that B. xylophilus could reproduce in Nordic forest lands. It is also likely that potential vector insects are present and could be functional in the establishment and epidemic development of the disease. Although temperatures in Nordic areas hardly seem conducive to pine wilt disease, other factors may contribute to disease expression. Research is needed on interactions of stress factors, particularly temperature and soil moisture, in the expression of pine wilt disease. A better understanding of these interactions would aid in evaluating the risk connected with an accidental introduction of the nematode into Nordic countries and provide a sound basis for trade regulations. At present, there are reasons to be most restrictive concerning any possible means of introduction of B. xylophilus.     

Survival of Bursaphelenchus xylophilus and Monochamus galloprovincialis in pine branches and wood packaging material

Survival and development of Bursaphelenchus xylophilus (pine wood nematode) was studied for up to 40 weeks in Pinus pinaster sawn wood and branches: 30 boards (1200 × 100 × 25 mm), 30 long‐blocks (1200 × 95 × 95 mm), 10 pine branches with bark and nine branches without bark (1200 mm long). The nematode was found in all materials and through the entire sampling period, with higher abundance in the sawn wood (boards and long‐blocks). In the initial period B. xylophilus reproduced abundantly and a population peak was detected at 8–12 weeks. Subsequently, the populations declined and became dominated by third‐stage resistant larvae (J_III), and in the final sample nematode abundance was very low. Nematode decline in the wood was correlated with a decrease in the moisture content (MC) to below fibre saturation. Survival of the insect vector Monochamus galloprovincialis was also assessed in sawn boards (1200 × 100 × 25 mm, n = 31) and blocks (160 × 95 × 95 mm, n = 40). The majority of the larvae were killed when sawing the wood, although some adults successfully emerged from the boards (10% survival) and blocks (37%). These results represent a contribution to the quantification of the risks of dispersing pine wilt disease through wood packaging materials, confirming that untreated wood can support healthy and abundant B. xylophilus populations for sufficient time for vectors surviving the sawing process to complete their development, to emerge and disperse the nematode.     

Cloning arginine kinase gene and its RNAi in Bursaphelenchus xylophilus causing pine wilt disease

Since Bursaphelenchus xylophilus causes serious losses in pine forestry, new ways of controlling this nematode damage are urgently needed. Arginine kinase (AK) is a phosphotransferase, which plays a critical role in cellular energy metabolism in invertebrates. It is only present in invertebrates and may be a suitable chemotherapeutic target in the control of this pest. RNA interference (RNAi) technology has been developed in biological science in recent decades as a powerful tool to silence the target gene function in the post-translational status. In this study, one AK gene, BxAK1 (GeneBank accession No. EU853862) was firstly cloned, and then its functions were identified by RNAi technology. Results show that the full-length cDNA of the BxAK1 gene contains 1206 base pairs and an 1086?bp open reading frame encoding 361 amino acids. The length of the BxAK1 genomic coding region contains 2430?bp consisting of four introns of 421, 117, 475, and 268?bp respectively, and five exons of 57, 207, 309, 360, and 215?bp respectively. A dsRNA targeting BxAK1 was constructed and tested for its RNAi effect on B. xylophilus by soaking bioassays. RNAi not only significantly increased the mortality of B. xylophilus, but also greatly reduced its fecundity and fertility. These results suggest that RNAi targeting BxAK1 may be an effective approach for controlling nematode pests.     

Temporal variation in contamination of pine engraver beetles with Fusarium circinatum in native Monterey pine forests in California

The relative importance of beetle species associated with Fusarium circinatum‐infected Monterey pines was investigated in three Monterey pine forests along the coast of central California, USA from April to November in 2004 and 2005. Fusarium circinatum was frequently isolated from Ips mexicanus and I. plastographus. The mean percentage isolation based upon numbers of I. mexicanus and I. plastographus carrying propagules of F. circinatum was 17·7 and 10·9% in 2004 and 16·7 and 17·3% in 2005, respectively. The mean percentage isolation was high in the spring and early summer and low in late summer and autumn in all three locations for both species. Isolation was higher from beetles emerging from harvested F. circinatum‐infected pine‐stems than for trapped beetles, 42·4% for I. mexicanus and 45·9% for I. plastographus. The mean (± SE) propagule load of trapped I. mexicanus was 269·5 (± 14·1) in 2004 and 281·7 (± 35·7) in 2005 and was 216·1 (± 28·9) in 2004 and 251·9 (± 28·4) in 2005 for I. plastographus. Mean propagule loads decreased from May to November in all locations for both species. Propagule loads of beetles emerged from infected stems were lower than that of trapped beetles, with means of 89·4 (± 23·2) and 93·0 (± 23·2) for I. mexicanus and I. plastographus, respectively. Thus beetles must acquire fungal propagules from more than one infected host. These results also suggest that higher contamination rates and propagule loads in spring and early summer may indicate a higher risk of pitch canker transmission, relative to late summer or autumn.     

云南省松材线虫病的发现与快速根除

2004年6月和11月，云南省德宏州的畹町经济开发区和瑞丽市的思茅松分别发生了松材线虫病，但在省各级政府的大力支持下，病害很快得到了稳定的控制。基于松材线虫病的危险性以及云南省抑制松材线虫病扩散的有效性，本文论述了云南省松材线虫病的发现和治理研究过程，并且总结归纳了治理松材线虫病的经验和方法，希望能为中国松材线虫病的综合治理工作提供有价值的参考信息。     

Guidance on sampling to detect pine wood nematode Bursaphelenchus xylophilus in trees, wood and insects

The pine wood nematode Bursaphelenchus xylophilus is the causal agent of pine wilt disease. It is a quarantine pest for most countries in the world. Surveys for the occurrence of the nematode may be necessary in the framework of internationally agreed phytosanitary standards, in order to delimit infested areas or to demonstrate the absence of B .  xylophilus and thus to identify pest free areas. Import inspections of wood and wood products also need sound monitoring systems. It is obvious that the quality of survey/monitoring, as well as the results of diagnosis, are strongly dependent on the sampling procedure. Although, in the literature, numerous results of surveys and monitoring are documented, sampling procedures vary and there is no scientific or statistically based sampling system published for B. xylophilus . The current paper relates background information concerning the biology of the nematode, its vector beetles and the development of pine wilt disease and the influence of these factors on sampling procedures, and attempts to define a more systematic methodology.     

春季松毛虫种群数量及其发生面积预测研究

为了监测春季松毛虫种群动态变化及进行综合防治; 利用1986-2012年阜新县松毛虫上树期死亡率、发生面积及同期的气象数据,采用相关及逐步回归的方法分析了松毛虫发生程度和发生面积与同期气象因素间的关系。结果表明：松毛虫在阜新地区有春季和秋季两个发生期,以春季发生较重,发生时间为3月下旬到6月上旬。上树前2月下旬温度和相对湿度对其复苏有很大影响,上树过程中温度是影响上树死亡的主要因子,其次是风速和相对湿度。在综合考虑多种气象因子、越冬死亡率、上树期死亡率和前一年发生面积等多种因素的情况下,最终确定以5种主要气象因子、越冬死亡率和前一年发生面积为预报因子建立发生面积预报模型,模型拟合结果和试报准确率均较好。     

Assessing risks of pine wood nematode Bursaphelenchus xylophilus transfer between wood packaging by simulating assembled pallets in service

The risks of Bursaphelenchus xylophilus (pine wood nematode) transfer in relation to wood material were assessed. Combinations of infested and non‐infested adjacent boards, long‐blocks and blocks of Pinus pinaster, simulating assembled pallets, were assessed. For the recipient wood, pieces with natural moisture content (MC), heat‐treatment (56°C for 30 min in the core) and kiln‐drying to <20% MC were tested, along with in‐service boards from pallets. Donor and recipient wood materials were kept in direct contact at 25°C or 10°C, with nine replicates per treatment. Bursaphelenchus xylophilus was found to transfer rapidly at 25°C when the wood had an MC above fibre‐saturation point (>30%). Nematode reproduction was rapid and sustained, gradually declining to zero at 40 weeks. Bursaphelenchus xylophilus did not transfer to kiln‐dried or to in‐service wood with an MC below fibre‐saturation point, or to wood at 10°C. The key factors determining nematode transfer were the ambient temperature, the nematode load of the donor wood and the MC of the recipient wood, with a ‘barrier’ of 20% MC below which it becomes unsuitable for nematode transfer. This finding indicates that there is a limited risk of spread of B. xylophilus in treated and untreated solid wood packaging materials.     

一种适合小花蝽实验观察的微养虫笼

介绍了一种适合小花蝽实验观察的新型微养虫笼。该微养虫笼利用透明的塑料培养皿(直径9 cm,高1.5 cm)、离心管(直径1.5 cm,高5 cm)和尼龙纱网(120目)制成。用封口膜和皮筋将微养虫笼封严,微养虫笼的离心管上锥一个小孔,便于加水。可用于小花蝽的基本生物学特性、群体饲养密度的确定、交配行为以及捕食行为、捕食量等试验研究。     

Emamectin benzoate as a candidate for a trunk‐injection agent against the pine wood nematode,Bursaphelenchus xylophilus

In order to develop an effective trunk‐injection agent against pine wood nematode, Bursaphelenchus xylophilus, an in vitro assay was used to examine the antinematodal activity of 58 commercially available compounds with known modes of action. Among compounds tested, the GABA receptor agonists had better anti‐nematodal activity than compounds influencing glutamate, N‐methyl‐D ‐aspartate, β‐adrenergic, dopamine, muscarinic acetylcholine and nicotinic acetylcholine receptors, as well as those inhibiting acetylcholinesterase, monoamine oxidase, 5‐hydroxytryptamine uptake and Ca²⁺, K⁺, Na⁺ and Cl⁻ channels. Avermectins and milbemycins strongly inhibited propagation of the nematode. Emamectin benzoate proved to be the most active (IC₉₅ 0.050 µM ) being over 140 times more active than the active ingredient of conventional trunk‐injection agents. It is concluded that emamectin benzoate is a strong candidate for an anti‐nematodal trunk injection agent. © 2000 Society of Chemical Industry