• KSBB Journal
• /
• v.15 no.1
• /
• pp.100-105
• /
• 2000

Optimal medium composition, culture conditions, characteristics of phase variation and activity of insecticidal toxin by Xenorhabdus nematophilus isolated and identified from Korean entomopathogenic nematode Steinernema carpocapsae were examined. Optimal medium composition of this strain was 50-70 g/L yeast extract, 3 g/L $K_{2}HPO_{4}$, 1g/L $NH_{4}H_{2}PO_{4}$, 2g/L ${MgSO}_4$$\cdot$${7H}_{2}O$, 10g/L NaCl and, these, yeast extract was found as a limiting nutrient for cell growth. When Monod equation was applied, maxmum specific growth rate and Monod constant were estimated as 0.13 $hr^{-1}$ and 20g/L, respectively. The pH of culture medium increased up to 8.5-9.5 regardless of initial pH 6-7 as the cells continued to grow. The specific growth rate in a 7 L fermentor was 0.18 $hr^{-1}$, which was enhancement 1.4 fold compared to a flask culture. In case of phase variation, phase I fraction was maintained above 90% at the stationary phase for both flask and fermentor cultures. According to oral toxicity test of Gallena mellonella by Xenorhabdus nematophilus, the addition of cell pellets into feed inhibited normal growth of insect larvae and killed completely then after 20 days cultivation. When culture supernatant of this strain was injected into hemolymph of insect larva, the toxicity was strongest at 24hr cultivation in the early exponential phase and gradually decreased as the culture time proceeded.

• Weed & Turfgrass Science
• /
• v.4 no.1
• /
• pp.58-64
• /
• 2015

The black cutworm, Agrotis ipsilon (Hufnagel) is a major insect pest of economic crops including turfgrasses on golf courses. The entomopathogenic nematode, Steinernema carpocapsae GSN1 strain (ScG), a Korean isolate, is an effective biological control agent for soil dwelling and greenhouse insect pests in Korea. In addition, ScG is commercially produced in Korea. We conducted laboratory, greenhouse, and field trials to evaluate efficacy of ScG against black cutworms in turfgrasses. A rate of 63 infective juveniles (Ijs) per larva killed >90% of $3^{rd}$ instars feeding in cups of artificial diet within 3 days. In greenhouse trials against cutworms feeding in pots of turfgrass, efficacy of ScG was higher against $4^{th}$ instars than against $2^{nd}$ instars (90.0 vs 81.2% mortality, respectively, at $2,000Ijs\;pot^{-1}$) in perennial ryegrass, and higher against $3^{rd}$ instars in creeping bentgrass, Agrostis palustris than in zoysiagrass, Zoysia japonica (96.7 vs 52.5% mortality at $100,000Ijs\;m^{-2}$) in pot. The corrected mortality of $4^{th}$ instar was 79.9% at the rate of $100,000Ijs\;m^{-2}$ in the creeping bentgrass in the field. So ScG could be used as biological control agent against black cutworm in turfgrass of golf courses.

• Asian Journal of Turfgrass Science
• /
• v.12 no.2
• /
• pp.127-140
• /
• 1998

곤충병원성 선충의 이용 효율을 높이기 위하여 곤충병원성 선충 상호간 또는 선충과 곤충병원성 곰팡이와의 상호관계를 알아보았다. Steinernema glaseri는 기주의 무게에 따라 성충수에서는 차이가 없었으나 침입태 유충수에서는 차이가 있었다. 선충의 접종 농도에 따른 침입 발육된 성충수는 기주당 20마리 이하의 접종에서는 차이를 보였으나 40마리 이상 1,000마리 접종구에서는 차이가 없었고, 증식된 유충수도 기주당 1,000마리 접종구에서 현저히 적은 것을 제외하고는 차이가 없었다. 동일 기주에서의 선충 상호간 관계에서는 steinernematid 선충에 의한 기주 치사율이 heterorhabditid 선충에 의한 것보다 높았다. 즉, 서로 다른 종의 곤충병원성 선충을 동일 기주에 접종하였을 때, S. carpocapsae 포천에 의한 기주 치사율은 $76.2\pm$4.8%였고 Heterorhabditis bacteriophora 함양에 의한 치사율은 $23.8\pm$4.8%였다. 또한 S. carpocapsae 포천에 의한 기주치사율이 각각 $90.5\pm$4.8%와 $80.9\pm$4.8%, H. bacteriophora NC 1에 의한 것은 9.5$\pm$4.8%였다. S. glaseri NC와 H. bacteriophora 함양 및 H. bacteriophora NC 1을 동시 접종하였을 때는 S. glaseri NC에 의한 것이 각각 $61.9\pm$9.65%와 $80.9\pm$4.8%, H. bacteriophora 함양에 의한 것이 $38.1\pm$9.5%, H. bacteriophora NC 1에 의한 것이 $19.1\pm$4.8%였다. 그러나 두 선충의 동시 감염은 관찰되지 않았다. 그리고 S. carpocapsae All과 곤충병원성 곰팡이인 Beauveria brongniartii를 동시 또는 곰팡이를 먼저 처리했을 때는 곰팡이 12시간 전 처리부터 선충과 곰팡이의 동시 감염이 관찰되었고, H. bacteriophora NC 1는 곰팡이 6시간 전 처리부터 동시 감염이 관찰되었다. 선충에 의한 감염과, 곰팡이에 의한 감염, 선충과 곰팡이 동시 감염은 곰팡이 48시간 전 처리부터 관찰되었다. 그러나 유충 증식수는 선충 단독 감염보다 동시 감염충에서 현저히 떨어졌다.

• The Korean Journal of Soil Zoology
• /
• v.1 no.1
• /
• pp.28-36
• /
• 1996

A survey for entomopathogenic nematodes was conducted throughout the nine provinvrd and within three city limits during the summer of 1990 and 1991. Six of the nine provinces and one of the three cities were positive for entomopathogenic nematodes. Out of the total 499 soil samples, 23(4.6%) were positive for entomopathogenic nematodes with 19(3.8%) containing Steinernema and 4(0.8%) containing Heterorhabditis. Heterorhabditis bacteriopora and three distinct groups of Steinernema species were idintified. One groups was indentified as S. carpocapsae, another S. glaseri and the other S. monticola based on cross breeding studies. Positive sample sites in each habitat includes 15 of the 415(3.6%) from forests including regrowth areas with shrubs, 1 of the 27(3.7%) from turfgrass including golf courses and parks, 3 of the 24(12.5%) from agricultural fields, 2 of the 16(12.5%) along riparian areas, and of the 17(11.8%) near the seashore. We advocate that more surveys be conducted for entomopathogenic nematodes before commercial sources of nematodes are widely applied which may obscure the naturally-occurring nematodes. A key to Steinernema is provided for the identification.

• Korean journal of applied entomology
• /
• v.40 no.1
• /
• pp.69-76
• /
• 2001

The entomopathogenic nematodes, Steinernema carpocapsae Pocheon strain (ScP) and Heterorhabditis bacteriophora Hamyang strain (HbH) were evaluated against chestnut insect pests, The farmers＇handling methods of chestnuts were taken into consideration to develop practical biological control with entomopathogenic nematodes . The major insect pests found with chestnuts were Curculio sikkimensis, Seichocrocis punctiferalis, and Cydia kurokoi. Although individual chestnut contained one species of insect was 58% representing 18% by C. sikkimensis, 27.7% by D. punctiferalis and 12.3% by C. kurokoi. The percentage of co-infection of C. sikkimensis with D. punctiferalis was 3.3%, C. sikkimensis with C. kurokoi 5.0%, D. punctiferalis with C. kurokoi 7.7%, and C. sikkimensis with D. punctiferalis and C. kurokoi 5.0%. The entomopathogenic nematodes, ScP and HbH were effective against all the species of chestnut insect pests. The $LC_{50}$ of ScP was 14.6 for C. sikkimensis, 4.6 for D. punctiferalis, and 5.6 for C. kurokoi and that of HbH was 49.2 for C. sikkimensis, 5.8 for D. punctiferalis, and 13.9 for C. kurokoi, respectively. When ScP was applied into pot including harvested chestnuts at the rate of 4,813 infective juveniles (Ijs)/pot $(=1\times10^9/ha)$, mortality of C. sikkimensis, D. punctiferalis, and C. kurokoi was 85.3%, 96.9%, and 68.1%, respectively. The mortality of C. sikkimensis, D. punctiferalis, and C. kurokoi was 60.73%, 96.5%, and 66.8%, respectively when HbH was applied at the same rate. Combination of two nematode species produced similar effects and insects were more infected by ScP than HbH. When chestnuts were soaked in the suspension of ScP at the rate of 300, 3,000, and 30,000 Ijs for 10 minutes or 30 minutes, mortalities of all chestnut insects were high irrespective of soaking time, concentration , and nematode species.

• Weed & Turfgrass Science
• /
• v.2 no.3
• /
• pp.312-317
• /
• 2013

The armyworm, Pseudaletia separata was occurred suddenly in a golf club in Namhae, Gyeongnam province in 2013. Thus, pathogenicity of seven species of entomopathogenic nematodes (Steinernema carpocapsae GSN1 strain, S. glaseri Dongrae strain, S. longicaudum Nonsan strain, S. monticolum Jiri strain and S. siamkayai, Heterorhabditis sp. Gyeongsan strain, and H. bacteriophora Hamyang strain) was evaluated against armyworm on tall fescue in pot and golf course to control this pest environmentally friendly. The pathogenicity against P. separata larvae was significantly different depending on nematode species. The corrected mortality of fifth instar of P. separata was 100% in the treatment with S. carpocapsae GSN1 in 7 days in tall fescue pot. However, there was not different in the mortality of fifth instar of P. separata (80 to 100%) at the rate of 385 to 6,160 infective juveniles (Ijs) ($=2.5{\times}10^2$ to $4{\times}10^5Ijs/m^2$) of S. carpocapsae GSN1 strain in each pot. Corrected mortality of P. separata was 65 and 60% at the rate of $10^5Ijs/m^2$ of S. carpocapsae GSN1 and S. longicaudum Nonsan strain, respectively in the tall fescue of golf course.

• Proceedings of the Korean Society of Applied Entomolohy Conference
• /
• 2001.05a
• /
• pp.75-75
• /
• 2001

• Proceedings of the Korean Society of Applied Entomolohy Conference
• /
• 2002.11a
• /
• pp.100-100
• /
• 2002

• Proceedings of the Korean Society of Applied Entomolohy Conference
• /
• 2005.05a
• /
• pp.162-162
• /
• 2005

• Proceedings of the Korean Society of Applied Entomolohy Conference
• /
• 2000.05a
• /
• pp.46-46
• /
• 2000