• The Plant Pathology Journal
• /
• v.24 no.2
• /
• pp.178-182
• /
• 2008

Five essential oils and 15 herbal extracts were evaluated to control Bursaphelenchus xylophillus in laboratory. The essential oils from clove plant (Syzygium aromaticum), mustard (Brassica integrefolia), thyme (Thymus vulgaris), and Pelargonium inquinans were found to be highly promising and gave excellent control of the nematodes at all the time of exposure. Among them, the least one gave 91.3% mean mortality rate at 24 hours of exposure time, which is highly significant from the control. While in the second study, most of the methanol (Desmodium caudatum, Paulownia coreana, Auckulandia lappa, Sophota flavescens, Aloe sp., Rheum palmatum, Zingiber officinale, Magnolia officinalis, and Eugenia caryophyllata), hexane (Torreya nucifera, Pharbitis nil, Prunus mume, Melia azedarach, and Xanthium strumarium), and hot water (Cinnamomum cassia) herbal extracts killed the nematodes, but in varying degrees compared to the control. Only one extract was found to be promising viz Magnolia officinalis which found to be statistically different from the control and gave mean mortality of 72, 82.3, and 85.3 % for 24, 48, and 72 hours exposure, respectively. Further screening was conducted for M. officinalis with concentrations of 1,000, 100, and 10 ppm against the same species of nematode with the same time of exposure. However, it gave an excellent result for 1,000 ppm for all time of exposure, whereas for the 100 and 10 ppm it gave mean mortality of 39.5 and 25.8% for the time 72hrs, respectively that were statistically different from the control.

• Korean Journal of Environmental Biology
• /
• v.34 no.4
• /
• pp.233-239
• /
• 2016

The purpose of this study is to investigate the response of the soil mesofauna and ground-dwelling arthropods to vegetation structure and composition in a mountain pasture. The pasture mainly comprised five types of plant communities; Agrostis alba - Phleum pratense community, Poa pratensis community, Festuca ovina community, Rumex acetosella community, and the shrub assemblage comprised Spiraea miyabei-Spiraea salicifolia community. Soil chemical properties including the pH, EC and nutrient levels were influenced by plant communities. Plant-specific responses were observed for bacteria-feeding and plant-feeding soil nematodes. Collembola and Oribatida having the same feeding habit were influenced differently by plants. nMDS showed that the community of ground-dwelling arthropods were separated by vegetation types. Species numbers of arthropods were different among different plant communities. Our results indicate that vegetation structure and composition can influence both abundance of diversity of terrestrial fauna.

• Korean journal of applied entomology
• /
• v.59 no.2
• /
• pp.83-91
• /
• 2020

We assessed efficacy of spraying pesticides from an unmanned helicopter to control two insect species, Monochamus alternatus and M. saltuarius, which are vectors of pine wood nematodes. Control efficacy of thiacloprid FL (33×), acetamiprid ME (33×), and flupyradifurone SL (33×) was determined by placing caged insects in the canopy of pine trees (Pinus sp). Water-sensitive paper was used to record the spray pattern of pesticide droplets and the degree of coverage; furthermore, we investigated peripheral scattering due to spraying. The three pesticides showed > 96% control efficacy against the targeted vectors, and pesticide droplet spray patterns were similar. Peripheral scattering was observed up to 20 m in front and 10 m to the left, right, and behind the targeted area. The coverage index of all the directions at 5 and 10 m distance was 6-7 and 2, respectively.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.8 no.2
• /
• pp.77-85
• /
• 2006

Entomopathogenic nematodes (EPNs) have been used as biological control agents for control of various agro-forest insect pests, and are especially effective against soil-dwelling insect pests. Effect of soil moisture on pathogenicity of commercial EPNs for white grub control was evaluated in laboratory, pots, and golf courses. Pathogenicity of EPNs in sand column was variable depending on depth, soil moisture, and EPN species or strain. All tested EPNs (Heterorhabditis sp. GSNUH1, Heterorhabditis sp. GSNUH2, Steinernema carpocapsae GSN1, and S. longicaudum Nonsan strain) showed similar pathogenicity against the bait insect, great wax moth (Galleria mellonella) larva at 2 cm deep at a given soil moisture. However, pathogenicity of the Heterorhabditis sp. GSNUH1 strain was decreased with increasing soil moisture. Pathogenicity of S. carpocapsae GSN1 strain was the lowest in 3% soil moisture (v/w) at 7 cm depth. However, there was no difference in pathogenicity between Heterorhabditis sp. GSNUH2 and S. longicaudum Nonsan strain. Although pathogenicity of Heterorhabditis sp. KCTC 0991BP strain showed no difference against the 2nd instar of Exomala orientalis, that of the S. carpocapsae GSN1 strain was decreased in the laboratory depending on soil moisture. Highly pathogenic strain EPN, Heterorhabditis sp. KCTC 0991BP strain, showed higher pathogenicity at 100 mm irrigation than non-irrigation or 10 mm irrigation. However, poor pathogenic strain EPN, S. carpocapsae GSN1 strain, was not different in pathogenicity from the 2nd instar of Exomala orientalis in creeping bentgrass (Agrostis palustris) depending on irrigation amount in the pot. Pathogenicity of EPNs in field experiment at the tee of Ulsan golf club showed a similar trend to that in the pot experiment.

• The Plant Pathology Journal
• /
• v.31 no.4
• /
• pp.441-445
• /
• 2015

Carrot (Dacus carota var. sativus) is one of the top-ten most economically important vegetable crops produced worldwide, and the root-knot nematodes, Meloidogyne spp., are one of the most important pests in the carrot. In Korea, M. hapla and M. incognita are presumed to be the major root-knot nematodes distributing mostly in open carrot fields and greenhouses, respectively. In our study, currently-developed and commercial carrot cultivars and the parental lines were examined for their pathological responses to M. incognita and M. hapla 7 weeks after inoculation with about 1,000 second-stage juveniles (J2) of the nematodes. All the carrot cultivars and lines showed susceptible responses to both nematodes with the gall index (GI) of 2.4-4.4, which were always higher on the carrot plants infected with M. incognita than M. hapla. Gall sizes were remarkably larger with more serious reduction of the root growths in the plants infected with M. incognita than M. hapla, suggesting the carrot lines examined in our study were more susceptible to the former than the latter. In the infection sites of the root tissues, giant cells were more extensively formed, occupying larger stellar regions with the prominent destruction of adjacent xylem vessels by M. incognita than M. hapla. All of these results suggest M. incognita affect more seriously on the carrot plants that are grown in greenhouses, compared to M. hapla that has a major distribution in open carrot fields, which would be used for determining cropping systems based on target nematode species, their damage and pathological characteristics.

• Parasites, Hosts and Diseases
• /
• v.57 no.6
• /
• pp.607-612
• /
• 2019

The aim of this parasitological study is examining contemporary (the late 20th century) specimens of the arctic or subarctic areas in Western Siberia and comparing them with the information acquired from archaeological samples from the same area. In the contemporary specimens, we observed the parasite eggs of 3 different species: Opisthochis felineus, Ascaris lumbricoides, and Enterobius vermicularis. Meanwhile, in archaeoparasitological results of Vesakoyakha, Kikki-Akki, and Nyamboyto I burial grounds, the eggs of Diphyllobothrium and Taenia spp. were found while no nematode (soil-transmitted) eggs were observed in the same samples. In this study, we concluded helminth infection pattern among the arctic and subarctic peoples of Western Siberia throughout history as follows: the raw fish-eating tradition did not undergo radical change in the area at least since the 18th century; and A. lumbricoides or E. vermicularis did not infect the inhabitants of this area before 20th century. With respect to the Western Siberia, we caught glimpse of the parasite infection pattern prevalent therein via investigations on contemporary and archaeoparasitological specimens.

• Journal of Veterinary Clinics
• /
• v.38 no.2
• /
• pp.75-81
• /
• 2021

An aquariid nematode, Desportesius invaginatus, was found in the proventriculus of an Egretta garzetta and a Bubulcus ibis from Chuncheon in the Republic of Korea. The worms were identified by light and scanning electron microscopy based on important taxonomic characteristics (body length, esophagus length, cordons, spicules, caudal alae of males, position of the vulva) and then phylogenetically analyzed using the 18S rRNA encoding gene. The nematodes were characterized by a body length of 7.0-8.0 mm in males and 10.2-13.1 mm in females, and two pairs of cordons recurrent in the anterior direction, and cordons were anastomosed by a longitudinal cuticular ridge that externally delimits a longitudinal canal. The widest cuticular plates of cordons bears over 20 posterior spines. The length of the spicules in males was also significantly different. The right spicule measured 742-821 (794) ㎛ in length and 40-45 (42) ㎛ in width, and the left spicule measured 493-556 (541) ㎛ in length and 11-13 (12) ㎛ in width. The caudal alae of males are inflated and vesicular in appearance. The vulva was situated at 56-71 (58.3) ㎛ from the posterior extremity. Although the 18S rRNA sequences of worms were similar to the Synhimantus species, some genetic divergences were observed in comparison. In this study, the worms were recognized with genus Desportesius because genus Desportesius was considered a subgenus of Synhimantus. This is the first record of D. invaginatus in the Republic of Korea.

• Korean Journal of Plant Resources
• /
• v.35 no.1
• /
• pp.23-28
• /
• 2022

The conversion of rice-fields to uplands is increased in last 8 years due to the government's policy. To obtain basic informations on plant-parasitic nematodes in converted uplands, we surveyed nematodes associated with crops cultured on the ridge of the rice-fields. The crops mostly cultivated at the ridge of rice-field were soybean (66%), red bean (21%), and perilla (13%). Ten important plant-parasitic nematodes species were identified: Helicotylenchus sp., Heterodera glycines, Meloidogyne arenaria, M. javanica, M. hapla, Paratylenchus projectus, Pratylenchus coffeae, P. neglectus, Rotylenchus incultus, Trichodorus sp. Tylenchorhynchus crassicaudatus, and T. claytoni. Among them, Rotylenchus incultus was the most common plant-parasitic nematode in all three crops. The ridge is a border of rice field, thus plant-parasitic nematodes infested on ridges should be cautioned for future cropping.

• The Korean Journal of Pesticide Science
• /
• v.19 no.2
• /
• pp.101-105
• /
• 2015

Efficacy of novel nematicide, imicyafos GR was evaluated against two species of the root-knot nematodes in pot and greenhouse conditions. When tested in pots, the population of Meloidogyne incognita and M. hapla was reduced sixty days after treatment, with mortality rate of 91.5% and 90.6%, respectively. Suppression effect of imicyafos GR on root galling in tomato was tested. The number of root galls caused by M. incognita and M. hapla was reduced 60 days after nematode inoculation, with the efficacy of 94.2% and 95.1%, respectively. Under greenhouse conditions planted with watermelon, melon, cucumber, and tomato, the efficacy of imicyafos GR on M. incognita persisted up to 60 days after treatment, showing 90% of control efficacy. Moreover, the number of root galling was more reduced than fosthiazate treatment, with the potential as a control agent.

• Korean journal of applied entomology
• /
• v.21 no.1 s.50
• /
• pp.8-14
• /
• 1982

Distribution and population of plant parasitc nematodes were investigated using 70 soil and root samples in total collected from six locations in Gyeongbug and Gyeongnam provinces. Among nematodes identified, Meloidogyne spp. was the most prevalent with $91.4\%$ in frequency cf detection. Frequency of detection was $87.1\%$ for Tylenchus sp., $24.3\%$ for Hirschmanniella, $23.3\%$ for Aphelenchus sp., and $20\%$ for Aphelenchoides sp.. Meloidogyne spp. was most abundant from samples collected in Namji and the number of nematodes dectected was 2,104 per $300cm^3$ soil. The number of Meloidogyne spp. detected was 671 from Milyang, 401 from Samrangjin. The number of nematodes was 57 from Samrangjin for Tylenchus sp., 127 from Gupo for Pratylenchus, 26 for Aphelenchoides sp. and 34 for Criconemoides from Samrangjin. Population of Meloidogyne spp. was the highest in Namji and Milyang where pepper and cucumber or pepper and chinese cabbage was cultivated in multiple croppings, however, population of Pratylenchus spp., and Meloidogyne spp. was the highest in Samrangjin where strawberry was cultivated as a single crop. Population in Pratylenchus and Meloidogyne was the highest in Gupo where tomato and chinese cabbage were cultivated alternatively, however, population of nematodes was generally low in Seongju and Yucheon where watermelon-rice or pepper-rice were cultivated in sequence. Meloidogyne spp. and Pratylenchus spp. appear to be economically important nematode species in cropping by controlled horticulture. In this study, 15 species of plant parasitic nematodes were identified.