• Research in Plant Disease
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• v.12 no.2
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• pp.108-114
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• 2006

This study was conducted to elucidate the interactions among soil microorganisms in a special field where one, two or three of N, P, K fertilizers were continuously not applied for 29 years. Crop yield (barley, soybean), soil chemical properties and microflora and microfauna including nematodes, nematophagous fungi, actinomycetes, bacteria, and fungi were examined for two years. Tylenchorhynchus sp. was the most important plant-parasitic nematode (range $11{\sim}642/300 cm^3$ soil) followed by Pratylenchus sp. and Helicotylenchus sp. Among nematophagous fungi, Monacrosporium spp. was the most frequently found followed by Harposporium sp. and Cystopage sp. In general, plots treated with phosphate fertilizer yielded more, had more nematodes, bacteria and actinomycetes. In contrast, total fungal population densities including nematophagous fungi, Cystopage sp. and Harposporium sp. were in reverse; they were more abundant in the plots with lower phosphate contents. Phosphate and pH are positively correlated and two most important determining factors for the population density of soil organisms under investigation. According to correlation analysis, Ca, Mg, and $SiO_2$ contents in soil and population densities of Tylenchorhynchus sp., saprophitic nematodes, actinomycetes, and bacteria were positively correlated with pH, but were negatively correlated with fungal population densities. We hope that the study will add an additional knowledges to understand our mysterious underworld.

• Korean journal of applied entomology
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• v.39 no.3
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• pp.171-179
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• 2000

- Turfgrass insect pests and natura.l enemies for biological control were investigated to develop pest management effectively in golf courses at several golf clubs. Twenty eight insect pest species of 10 families in 6 orders were collected from golf courses. The zoysiagrass mite, Eriophyes zoysiae and root-knot nematode, Meloidogyne incognita were also collected from zoysiagrass. White grubs of several scarab beetles and cutworms (Agrotis spp.) damaged seriously at most surveyed golf clubs. In addition, bluegrass webworm (Crambus sp.), Japanese lawngrass cutworm (Spodoptera depravata), scale insects, Tipula sp., and ants (Camponitus japonicus, Formica japonica, and Lasins japonicus) damaged turfgrasses directly or indirectly in golf courses. The entomopathogenic nematodes, Heterorhabditis spp., Steinernema glaseri, and S. longicaudum, entomopathogenic fungi, Beauveria bassiana and Metarhizium anisopliae, and milky disease, Paenibacil/us popil/iae were isolated from white grubs or turfgrass soil as microbial control agents. Besides, dipteran predators, Cophinopoda chinensis, Philonicus albiceps, and Promachus yesonicus and hymenopteran parasitoid, Tiphia sp. were also collected. The P. yesonicus was the most active in golf courses. The root-knot nematode, M. incognita was found from Zoysia japonica, Z. matrella. and Cynodon dactylon.

• 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.