• Asian Journal of Turfgrass Science
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• v.19 no.1
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• pp.39-46
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• 2005

The 21 strains of Korean entomopathogenic nematodes, {Heterorhabditis bacteriophora Hamyang strain(HbH), Heterorhabditis sp. 202, 205, 217, Heterorhabdiris sp. KCTC 0991BP strain, Steinernema carpocapsae Pocheon(ScP), S. longicaudum Gonaju, S. longicaudum Nonsan, Steinernema sp. 7,24, 52, 55, 60, 64, 206, 207, 209, 210, 219, and 227 strain} were evaluated for the control of a turfgrass insect pest, Exomala orientalis. Heterorhabditis spp. showed higher pathogenicity than Steinernema spp. against 3rd instar larvae of E. orientalis with $55\%$ mortality by Heterorhabditis sp. 202 strain and $50\%$ by HbH and Heterorhabditis sp.205 strain at the rate of 200 infective juveniles per larva 14 days later after treatment. The number of infective juveniles of Korean entomopathogenic nematodes in 3rd instar larvae of E. orientalis was higher in Heterorhabditis spp. than in Steinernema spp.. In general, numbers of produced infective juveniles of three species were much higher, i.e., Heterorhabditis sp.202 strain produced 273,064 infective juveniles, S. carpocapsae Pocheon strain 273,043, and Heterorhabditis sp. 217 strain 248,887, respectively.

• The Korean Journal of Pesticide Science
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• v.10 no.2
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• pp.107-116
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• 2006

Korean entomopathogenic nematode strain were evaluated against white grubs, Popillia quadriguttata, Ectinohoplia rufipes and Phyllopertha diversa in laboratory. In addition we examined the efficacy of entomopatogenic nematode, Heterorhabditis sp. KCTC 0991BP strain against white grubs in Seaside Golf Club in Gimpo, Gyeonggii and persistence of entomopatogenic nematode in fairway of Anyang Benest Golf Club in Gunpo, Gyeonggii. In laboratory Heterorhabditis bacteriophora Hamyang strain showed 95% mortality against Popillia quadriguttata. H. bacteriophora Hamyang strain and Heterorhabditis sp. KCTC 0991BP induced 80% mortality against 3rd instar of Ectinohoplia rufipes. However, the letter showed only 60% mortality against Phyllopertha diversa. White grub density was reduced to 39% by the application of Heterorhabditis sp. KCTC 0991BP at the rate of $2.24{\times}10^9$ infective juveniles $ha^{-1}$ compared with control in Seaside Golf Club. Heterorhabditis sp. KCTC 0991BP persisted for two months at $5{\sim}10$ cm soil depth but not persisted at $0{\sim}5$ cm soil depth for the same periods when applied at the rate of $2.47{\times}10^9$ infective juveniles $ha^{-1}$.

• Korean journal of applied entomology
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• v.34 no.4
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• pp.314-320
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• 1995

Pathogenicity of Korean entomopathogenic nematodes against local insect pests was different depending on strains or target-insect pests. Mortalities of diamondback moth, Plutella xylostella larvae were 51.8%, 77.8%, 96.3% or 100% in Hanrim Steinernema sp. and 50.0%, 74.1%, 96.3% or 98.1% in Hamyang Heterorhabditis sp. on filter paper when larvae were exposed to 3, 6, 12, or 24 nematodes per larva. Mortalities of them on kale leaves at the same concentration were 44.4%, 63.0%, 76.1%, or 94.5% in Hanrim Steinernema sp. and 79.7%, 81.6%, 94.4%, or 100% in Hamyang Heterorhabditis sp., respectively. In field test, control value of Hanrim Steinernema sp. was 72.0% and that of Hamyang Heterorhabditis sp. was 84.1% in 14 days when 300,000 nematodes were sprayed to each plot ($13.27\m^2$). Although mortalities of rice stem borer, Chilo suppressalis larvae showed no difference at high concentration, Hamyang Heterorhabditis sp. (47.3~100%) was more effective than Hanrim Steinernema sp. (34.3~83.3%) at low concentration, 50~200 nematodes/ml. When chestnut curculio, Curculio sikkimensis larvae were treated with Sancheong Steinernema sp. and Hamyang Heterorhabditis sp., respectively. When pellucid zygaenid, Pryeria sinica larvae were exposed to nematodes, Pocheon Steinernema sp. was effective ranging from 96.7% to 100% but mortalities of them were 63.3~76.7% in Dongrae Steinernema sp..

• Microbiology and Biotechnology Letters
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• v.29 no.2
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• pp.104-109
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• 2001

The yield of infective juveniles of Heterorhabditis bacteriophora (Tf strain) in vitro monoxenic liquid culture was improved significantly as the amount of symbiont biomass, Photorhabdus sp. strain Tf, increased. To investigate the influence of abiotic factors on the growth and biomass production of Photorhabdus sp. strain Tf, triplicate flask cu1tmes were performed. The optinal temperature and medium pH for the growth of Photorhahdus sp. strain Tf were 30$^{\circ}$C and between pH 5.5-7.3, respectively. Aeration also improved greatly growth and yield of biomass of Photorhabdus sp. strain Tf. Photorhabdus sp. strain Tf in batch fermentation showed growth-associated pattem in terms of pigment production, and the pH of culture medium rose steadily until growth stopped dUling the fermentation. Both pigment production and culture pH rise would be useful parameters indicating a reliable growth of Photorhabdus sp. strain Tf.

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

• Korean Journal of Organic Agriculture
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• v.30 no.3
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• pp.423-439
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• 2022

The acute dermal and eye irritation tests of Photorhabdus temperata, a symbiotic bacterium of Heterorhabditis megidis Gwangju strain, were carried out in New Zealand white rabbit (Oryctolagus cuniculus), following the guidelines of OECD and Rural Development Administration (RDA) of Korea. In both tests, neither dermal nor eye responses were found from all the P. temperata treated rabbits and the results were classified as non-irritating. That is, erythema, eschar, edema, and any other dermal critical signs were not observed from all the experimental rabbits in the dermal irritation test. In the acute eye irritation test, no clinical signs of cornea, iritis, conjunctiva (redness, edema, lacrima, and chemosis) were observed from all the experimental rabbits. Individual ocular irritation, mean ocular irritation, and acute ocular irritation were calculated as 0.0. The results of dermal and eye irritation studies on P. temperata indicated that this bacterium could be a safe and effective alternative bionematicide against the most serious plant-parasitic root-knot nematodes in the genus Meloidogyne.

• The Korean Journal of Soil Zoology
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• v.8 no.1_2
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• pp.17-22
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• 2003

An endemic entomopathogenic nematode, Heterorhabditis megidis, was evaluated by its control efficacies against housefly, Musca domestica, and flower beetle, Gametis jucunda. In Petri-dish assay, the pathogenicity of H. megidis showed 456.4 infective juveniles/larva (IJs/larva) in median lethality (LC$_{50}$) against the second instar larvae of M. domestica and 238.9 IJs/larva against the second instar larvae of G. jucunda. This was contrasted with those of the other well-known entomopathogenic nematode, Steinernema carpocapsae, which showed 115.9 IJs/larva against M. domestica and 388.6 IJs/larva against G. jucunda. In field experiment, H. megidis were applied per square meter of pork farm with 1,000,000 IJs of H. megidis or apple orchard with 370,000 IJs, which were infested with M. domestica or G. jucunda, respectively. H. megidis showed 56.9% and 57.3% of control efficacies against M. domestica and G. jucunda, respectively. These results suggest a promising control technique in the field using H. megidis against M. domestica and G. jucunda.a.

• Korean journal of applied entomology
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• v.30 no.1
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• pp.50-53
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• 1991

The entomopathogenic nematodes, Steinernema carpocapsae and Heterorhabditis bacteriophoTa, were laboratory tested for the control of rice stem borer Chilo suppressalis. When 8 cm long of two rice stems infected by rice stem borers were treated with S. carpocapsae by spray application to the concentrations of 250, 500, 1,000, or 2,000 nematodes/ml, 68.6 $\pm$ 10.0-94.9 $\pm$ 2.6 % control was obtained. When 8 cm long of rice stems infected by rice stem borers were treated with H. bacteriophoTa by spray application to the concentrations of 100, 200, 400, or 800 nematodes/ ml, 91.4 $\pm$ 0.7-100 % control was obtained. On the other hand, when 8 cm long of three rice stems were treated with H. bacteriophora by dipping application to the concentrations of 100 or 200 nematodes/ml, 46.2 $\pm$ 4.7-63.1 $\pm$ 4.7 % control was obtained. Because the moist habitat of rice stems were favorable to nematode survival and searching abilities, entomopathogenic nematode, were confirmed to be a potential biological control agents against rice stem borers.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.09a
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• pp.107-110
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• 2001

The biological control potential of entomopathogenic nematodes (EPN) can be enhanced by improved culture efficiency. Optimization of media is a key factor for improving in vitro mass production of entomopathogenic nematodes. EPN yield was dependant of complex medium concentration, of which mixture is carbohydrates, lipids, proteins, salts, and growth factors, on the growth of Heterorhabditis bacteriophora and its symbiotic bacterium Photorhabdus luminescensLipids.

• Korean journal of applied entomology
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• v.46 no.1 s.145
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• pp.147-151
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• 2007

Laboratory tests were conducted to determine the susceptibility of the alfalfa weevil, Hypera postica to Korean entomopathogenic nematodes, Steinernema carpocapsae GSN1 strain (ScG), S. glaseri Dongrae strain (SgD), Heterorhabditis bacteriophora Hamyang strain (HbH), and Heterorhabditis sp. Gyeongsan strain (HeG) at the petri dish assay. The larval mortality of H. postica was significantly different depending on nematode species and treatment concentration. SgD and HeG strain were more effective against H. postica larva than ScG and HbH strain. When SgD and HeG strain were treated with the rate of >20 infective juveniles (ijs) per alfalfa weevil larva, mortality was ca. 77.5-100% at the late instars of H. postica in 3 days. The number of established nematode was significantly different depending on nematode species, whereas number of progeny was not significantly different. The mean number of established us of SgD strain in a host was the highest at 80 ijs by 30.2. The highest progeny number of HeG strain was 2,671.5 with 80 ijs. All nematode strains were not parasitic entirely to H. postica adults. These results show that alfalfa weevil late larva is highly susceptible to Korean entomopathogenic nematodes in the laboratory.