• Research in Plant Disease
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• v.16 no.3
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• pp.299-305
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• 2010

Objective of this study is to examine whether pine wood nematode (PWN: Bursaphelenchus xylophilus) in the sawdust discharged from infected trees cause pine wood disease or not. For this, survival time of PWN in soil was examined in which soil moisture was controlled as 15%, 22.5%, and 30% in volume ratio, respectively. The pathogenicity tests were conducted under greenhouse and field conditions. Survival time of PWN in soil was about three days in the saturated (about soil moisture of 23% in volume ratio) and dark condition between 25 and $28^{\circ}C$ of room temperature. None of potted seedlings with non-wounded roots was infected by PWN in sawdust. In field, pine wood disease was not occur in any pine trees. These results indicated that PWN discharged on soil when the infected trees were cut by chain saw can not cause pine wood disease.

• The Korean Journal of Pesticide Science
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• v.19 no.4
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• pp.440-449
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• 2015

Pine wood nematode (PWN), Bursaphelenchus xylophilus is one of the most serious pests of pine tree. Trunk injection of some nematicides in tree is well known as an effective control method. However there are some limitating factors which hindering the efficacy of trunk injection in field or potted tree. In this study we suggested easy and useful alternative screening methods of nematicides against PWN. Reproduction of PWN was influenced by tree twig moisture (high reproduction in high moisture trig) and paraffin coating was 78.6% reduced moisture loss in tested twig. There were no reproduction different in up and down site from infection site of twig at 1 month after inoculation of PWN and also distance (5 and 10 cm) from inoculation site of PWN did not influence the reproduction of PWN. Numbers of reproduced PWN were higher with decreasing diameter of twig. Numbers of reproduced PWN were similar to P. thunbergii and P. densiflora. However reproduction was increased depending on high inoculation density and longer propagation period. When inoculation of PWN on cut twig injected with emamectin benzoate 2.15% EC and morantel tartrate 8% SL in trunk of Pinus thunbergii in the field, PWN number were significantly reduced than untreated control. We suggest this screening method for PWN control agents.

• The Korean Journal of Pesticide Science
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• v.12 no.4
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• pp.391-396
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• 2008

The pine sawyer, Monochamus saltuarius Gebler (Colepotera: Cerambycidae) was newly known as a vector of pinewood nematode causing the pine wilt disease in Korean white pine (P. koraiensis Siebold & Zucc.) forestry. Recently, it has a serious problem to spread fast and widely throughout Korea by transferring M. saltuarius. For the control of M. saltuarius, this study was investigated the attractants by analyzing from the Korean white pine. Major components of Korean white pine was analyzed as $\alpha$-pinene and ethanol, and reported as an attractant against Monochamus genus. Ipsenol and ipsdienol, the pheromones of Ips genus known as attractant components of woodboring beetles, were tested to the attractive efficacy against Monochamus saltuarius. The attractive efficacy showed 67.9% of Ipsenol plus ipsdienol and ipsenol, ipsdienol mixed with $\alpha$-pinene plus ethanol was showed 67.7% and 79.3%, respectively. Especially, ipsdienol with $\alpha$-pinene and ethanol was shown the high synergy effect, and the attractant effect was higher at M. saltuarius female than male.

• The Korean Journal of Pesticide Science
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• v.20 no.1
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• pp.56-65
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• 2016

Pine wood nematode, Bursaphlenchus xylophilus is a fatal damaging pest, infecting pinewood trees and is one of the serious forest pest in Korea. Trunk injection is one of the most effective method to protect the live pine trees from nematode infection. The aim of this research was to reveal the efficacy of the nematicidal materials from 46 Kyrgyzstan, 88 Vietnam plant materials and 21 active materials (${\alpha}$-terpinene, ${\alpha}$-pinene, ${\beta}$-thujaplicin, cinnamaldehyde, eugenol, emodin, geraniol, limonone, methyl palmitate, matrine, myrcene, methyl gallate, nicotine, quassin, resveratrol, rotenone, thymol, thujaplicin, terthiophene, tuberstemonine, ${\gamma}$-terpinene) isolated from plants for using as trunk injection agents. Eclipta prostrata extract was highly effective against pine wood nematode in plant extracts and terthiophene has the best nematicidal activity from active materials isolated from plants. Foliar spray of terthiophene on Japanese black pine (Pinus thunbergii) tree reduced proliferation of inoculated pine wood nematode at 22 days after treatment, however no efficacy was found over 22 days. Eclipta prostrata extract and terthiophene can be used as nematicide for further nematicidal efficacy test against any other plant parasitic nematodes and trunk injection efficacy against pine wood nematode.

• Korean journal of applied entomology
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• v.53 no.2
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• pp.141-147
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• 2014

Pinewood nematode (PWN: Bursaphelenchus xylophilus) is known to kill pine tree species that are indigenous to countries where the pest was inadvertently imported, but some cultures from the extraction of dead pines do not damage trees. Experiments were conducted to examine the effect of pre-inoculation of these low-pathogenic pinewood nematode on resistance of pine trees against the pest species. The pre-inoculated pine saplings showed induced resistance which lasted for a year, and repeated inoculation of these low-pathogenic nematodes enhanced tree resistance. All nematode samples extracted from dying or dead pines that had been killed not more than three months before the extraction were pathogenic, and most of those extracted from pines that had been killed 2-3 years before were low-pathogenic. When inoculated in pine saplings, number of low-pathogenic nematodes settled, as studied two days after inoculation, was not different from that of pathogenic ones. However, as studied after 30 days of inoculation, rate of reproduction in low-pathogenic nematodes was far lower than that of pathogenic nematodes. The rate of reproduction of several nematode isolates growing on fungal mat media of Botrytis cinerea varied, but three of four low-pathogenic isolates showed same level of reproduction rates as pathogenic ones.

• Korean journal of applied entomology
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• v.57 no.1
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• pp.7-13
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• 2018

Currently, there is no available tool that rapidly diagnoses pine wood nematode (PWN)-infected pine trees in the field. In this study, we synthesized and purified PWN Galectin, which might be an antigen specific to PWN, using the Baculovirus expression system. We used PWN Galectin as an antigen for generating 1,464 fusion hybridoma cell lines secreting monoclonal antibodies (Mabs). Among them, we selected 62 fusion hybridoma cell lines showing high reactivity to PWN Galectin. We further selected 12 fusion hybridoma cell lines showing high reactivity to the standard PWN-infected pine tree phosphate buffered saline (PBS) extract. Additionally, two fusion hybridoma cell lines showing no or extremely low reactivity were used as controls. The selected fusion hybridoma cell lines were subjected to limiting dilutions for selecting and establishing Mab-secreting cell lines showing higher reactivity to the standard PWN-infected pine tree extract than to the standard normal pine tree PBS extract. Moreover, the selected fusion hybridoma cell lines were further selected based on their higher reactivity to PWN protein extracts than to three non-pathogenic nematode protein extracts. The Mab-secreting cell lines established in this study could be used to develop rapid diagnostic tools that can be used in the field or in laboratories for detecting PWN-infected pine trees or PWN.

• Journal of Life Science
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• v.25 no.12
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• pp.1445-1449
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• 2015

The pinewood nematode Bursaphelenchus xylophilus (Nematoda: Parasitaphelenchidae) poses a serious threat to pine forests in Europe and East Asia, leading to a debilitating pine wilt disease. Infected pine trees in Korea are generally fumigated or crushed to small wood chips after felling. Although pine wilt disease often recurs in pest management sites, there are no adequate means to monitor the effectiveness of pest control measures in those sites. Recently, a male-produced aggregation pheromone, 2-(undecyloxy)ethanol, was shown to be useful for attracting several Monochamus species, which are vectors for the pinewood nematodes. In this study, we investigated the abilities of 2-(undecyloxy)ethanol at three different doses (175, 350, and 700 mg), as well as host plant volatiles (α-pinene and ethanol), to attract M. alternatus (Coleoptera: Cerambycidae) at a pine forest in Pohang, Korea where infected pine trees had been cut down and fumigated. Twenty-seven M. alternatus were captured in cross-vane panel traps made of polyethylene terephthalate bottles and acrylic sheets. The results indicate that a high dose of 2-(undecyloxy)ethanol (700 mg per trap) is the most effective for attracting M. alternatus. The aggregation pheromone could be used to monitor the effectiveness of pest control measures as well as M. alternatus populations.

• Korean journal of applied entomology
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• v.43 no.1
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• pp.85-89
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• 2004

Numerical measurements were made for fresh weight, body length and width, head width, and color and length of antenna of Japanese pine sawyer, Monochamus alternatus adults, a primary vector of pine wood nematode, Bursaphelenchus xylophilus in Korea. We measured 563 females and 601 males that emerged out of dead pine logs from 2001 to 2002. General linear model analysis showed that measurements of fresh weight, body length, and body width were significantly higher in females than in males. Head width was not significantly different between sexes. Antennal length of males was significantly longer than that of females. For females and males respectively, average fresh weights were 0.305g and 0.277g, body lengths 20.97mm and 19.93mm, body widths 6.52mm and 6.18mm, head widths 3.78mm and 3.70mm, and antennal lengths 31.19mm and 45.49 mm. Antennal length or ratio of antennal length to body length overlapped in some ranges between 2 sexes. Therefore antennal length itself or ratio of antennal length to body length could not be used as a definite criterion to discriminate sexes. However, check on color of the antennae of 4,033 adults revealed without exception that basal part of every segment of flagellum of female antenna was covered with whitish-grey hairs, while whole part of every segment of male flagellum was covered with brownish-black hairs. This characteristics might be a best way to differentiate sex of this species.

• Journal of Life Science
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• v.20 no.5
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• pp.644-648
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• 2010

The influence of nematodes on nematophagous fungi has seldom been investigated. In the present study, the influence of pinewood nematode on its endoparasitic fungus, Esteya vermicola, was investigated systemically. Although both nematodal metabolite and nematodal homogenate could stimulate and speed up the growth of E. vermicola, the impact of nematodal metabolite was slightly higher than that of nematodal homogenate. In addition, a method was developed to investigate the influence of volatiles, discharged by pinewood nematodes in their metabolic process, on the growth of E. vermicola. Reproductive results were given and confirmed that nematodal volatiles have no influence on the cell growth of E. vermicola. This study may provide information for the application of E. vermicola as biological control agent of pinewood nematode.

• Research in Plant Disease
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• v.18 no.2
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• pp.101-108
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• 2012

In 2006, pinewood nematode, Bursaphelenchus xylophilus, was isolated from about 50 years old trees of Pinus densiflora and P. koraiensis showing leaf-wilt and -drying symptoms in Gwangju, Gyeonggi-do and Chuncheon, Gangwon-do. Isolation of pinewood nematodes from sapwood of infected pine trees showed no difference in population density between tree species and among the sampling heights on the main stem. Migration of pinewood nematodes in the host tree were investigated by inoculation of red pine (P. densiflora, 3 years old) seedlings with B. xylophilus. The nematodes seemed to move in red pine seedlings prior to multiplication and it might have taken about 20 days to start multiplication and expression of symptoms including wilt and dieback. In initial time after inoculation, nematodes started migration through the cortical resin canal from inoculated site and further showed upward and downward movements. More nematodes were observed in cortical resin canal during early period of inoculation and later in resin canal of xylem and tracheid also while, the pith still remained free from nematode. The density of B. xylophilus was higher in seedlings of low-vigor with poor root growth than in seedlings of normal root growth. Seedlings showing high density of B. xylophilus exhibited stem discoloration and secondary infection by fungus at the inoculation site.