• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.3
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• pp.369-374
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• 2014

The rice stem borer (Chilo suppressalis Walker) was one of the most destructive pest of rice for the 1960s and 1970s in Korea. Recently, it is newly recognized as a potential risk factor to the biomass yield of bioenergy crops. The current research was firstly conducted to investigate overwintering larvae population density and pattern of rice stem borer attacking Miscanthus sacchariflorus cv. Geodae 1 which is referred to as an ideal lignocellulosic bioenergy crop in Korea. Population density of larvae per $1m^2$ in stems and rhizomes at the Miscanthus experimental plots and rates of damage (wormhole, abscission) of M. sacchariflorus cv. Goedae 1 were investigated from October 2012 to March 2013. The population of larvae per $1m^2$ in stems of Miscanthus were 23, 4, 1, and 1 in October, November, December 2012, and January 2013, respectively. Over the same period, the population of larvae in basal stem rots and rhizomes were increased, whereas decreased in stems. Interestingly, the positions of larvae for overwintering in Miscanthus were confirmed to 5~10 cm below the soil surface such as basal stem rot and rhizome, whereas the most common overwintering position known in rice is a part of stem on the ground such as rice straw and rice stubble. It would suggest that the larvae gradually moved to bottom of stems and rhizomes in soil in line with decline in temperature. Moreover, the damage rates of stems per $1m^2$ were up to more than 50% in some places. In conclusion, this might be the first report that rice stem borer could affect the productivity of biomass of Miscanthus in case of mass cultivation. Moreover, it should be necessary to make a decision in insect control management for this bioenergy feedstock and other related crops.

• Korean journal of applied entomology
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• v.30 no.4
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• pp.249-257
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• 1991

Chronological changes in the occurrence pattern of the striped rice borer(SRB), Chilo suppressalis Walker, were investigated by analyzing the data collected by 33 light traps of the countrywide monitoring units during the period of 1968-1989. And also relation of incidences between larval and adult populations, emergence time and percent emergence of overwintered larvae were observed in relation to the time of different rice transplantations. Spring moths of SRB in 1985-'89 generally emerged earlier than in 1968-'72 : 30 days earlier at Kwangju, 20 -25 days earlier at Sangju and Naju, 10-15 days earlier at Uljin, Jinju, Goyang, Milyang, Kimhae, etc., 5 days earlier at Suweon, Jinchun, Daejeon, Namweon, Haenam, etc. There was no change in the time of spring moth emergance at Weonseong, Chungju, Seosan, Yongju, and Nonsan. Summer moths of SRB in 1985- '89 also emerged earlier than 1968- '72: 20 days earlier at Uljin, 15 days earlier at Chungju, Yeongdug, and Habchun, 5-10 days earlier at the other areas except Yeongju. There was an overall countrywide decrease in the population of the 1st generation of SRB during the last two decades. The population of the 2nd generation also decreased in 19 areas during the same period, but increased in 14 areas including over 3-fold increases in Kwangju, Naju and Daegu, and double increase in Jinju, Milyang and Gongju. The higher larval population density of 1st genration was taken place in the earlier transplanted fields, whereas the population of 2nd generation were higher at mid-season transplanted (May 30), followed by May 15, June 15, and April 30. The peak of larval population appeared generally 15 days after moth peak in 1st generation, and 10 days after moth-peak in 2nd generation. The earlier transplanted fields were the higher percent damage due to 1st off-springs of spring moths, whereas the fields transplanted in mid-season were higher damage due to 2nd off-springs of summer moths. Average body weights of SRB larvae before overwintering were 65.6 mg, 61.2 mg, and 55.5 mg in early, mid-season, and late transplantations, respectively. In field cage experiments, emergence rate of the overwintered larvae ranged from 28.3-39.8%. In other words, body weights of overwintering larvae were heavier in fields by earlier transplantation, and heavier larvae showed higher percentage of adult emergence. The period from overwintered larvae to adult emergence was longer in the fields of the later transplantations; namely, 44, 49, and 51 days for early, mid-season, and late transplantations, respectively.

• Korean journal of applied entomology
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• v.12 no.1
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• pp.29-32
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• 1973

This experiment has been carried out to establish the most effective rearing method of rice stemborer, Chilo suppressalis (Walker) on artificial diets under the aseptic condition. The results obtained were summarized as follows: 1. Semi·synthetic diet was giving better results in the weight of matured larvae (96.4mg), emerging rate$(96.7\%)$ and number of egg masses (2.6) than other diets studied. 2. Number of egg masses and hatching rate were significantly increased on the semi-synthetic diet and chemically defned diet, and it may be due to the choline chloride in the diets, 3. Rice seedling was used as a convenient food material. However, it requires more labours and causes more damages of larvae in replacement of fresh seedlings. 4. A different result in larval weight and pupation rate was observed between simplified diet no. 1 and diet added with chlorella. 5. Simplified diet resulted in low hatchability in the second generation, which may be due to the mulnutrition of the diet for adults. 6. The pupation rate was significantly decreased by infection of microorganisms on matured larvae.

• Korean journal of applied entomology
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• v.4
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• pp.51-54
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• 1965

The study was initiated to investigate the nature of varietal resistance to the rice stem borer (Chilo suppressalis WALKER), specially the rotation of the resistance to the silica and nitrogen content of the host Plants. 1. The body freight of the larvae, reared on the stem of the various varieties of rice plants, when weighed at the age of 25 days old, showed great variation, and ranged from 21.24 mgrs. to 45.77 mgrs. depending on the used varieties of tile rice plants. And generally the varieties of Indica types were showed greater body weight than that of Japonica types in this experiments. 2. The positive correlation coefficients of percent survivals to body weight, developement, oviposition preference and rate of damage to host plants were significant, and consequently the percent survival could be used as a criteria of resistance. 3. The content of silica in the host plants was significantly correlated with both the degree of boring on the leaf and attractovemess of larvae, and the total nitrogen content of plants showed significant positive correlation coefficient with larval attractivenes, but not significant with the degree of boring on the leaf. 4. Since the attractiveness and boring manner were significantyly correlated to resistance criteria of rice plant to the pest, it could be considered that the resistance is the results of chain reaction of the factors mentioned above.

• Korean journal of applied entomology
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• v.14 no.4 s.25
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• pp.214-214
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• 1975

This study was conducted to evaluated the nature of the variety Tongil(Suweon 213-1) in resistance to the striped rice borer, Chilo suppressalis Walker, comparing with those of Rexoro(susceptible check) and TKM-6(resistant check) selected at IRRI. 1. The striped rice borer moths much more preferred the variety Tongil for oviposition than the varieties Rexoro and TKM-6. The variety Tongil and more egg masses and number of eggs than the varieties Rexoro and TKM-6, while TKM-6 having more egg masses and more number of eggs than Rexoro. This reaction was consistent throughout the test regardless of the number of tillers per hill. 2. In laboratory, preference of larvae for feeding was studied with 5cm of stem pieces of the varieties. The results showed, in contrast to the case of ovipositional preference, that the striped rice borer larvae least preferred the stems of Tongil among the test varieties, while larvae much more preferred the stems of Rexoro than those of TKM-6. 3. The larval weights at 20 days later infested on the 40 day-old plants were the lowest on Tongil among the test varieties. On the variety Rexoro the larvae had heavier body weights(43.0mg), higher pupation(64.9%) and higher adult emergence(83.3%) than those on Tongil(larval weights 30.3mg, pupation 60%, adult emergence 60.7%) and TKM-6(larval weights 35.7mg, pupation 56.3%, adult emergence 51.9%). The pupal weights, however, were not consistent among the test varieties and/or sexes in comparison with the larval weights, pupation and adult emergence above mentioned. 4. Field experiments indicated that the incidence of dead hearts at 70 days after transplanting was relatively higher on the variety Tongil(11.1%) than those on Rexoro(8.9%) and TKM-6(8.4%), and the incidence of white heads at harvest was, in contrast to the dead hearts, lower on Tongil(9.8%) than those on Rexoro(27.4%) and TKM-6(13.9%). At harvest lower larval survival observed on Tongil (49 larvae/40 hills) than those on the susceptible variety Rexoro(104 larvae/40 hills) and on the resistant variety TKM-6(70 larvae/40 hills). The average larval weights collected from three test varieties at harvest were 80.5mg from Tongil, 83.7mg from TKM-6 and 99.6mg from Rexoro. 5. Increased nitrogen fertilizer application to the variety Tongil, the striped rice borer damage was increased. Also, preference of larvae for feeding significantly increased with the increase of nitrogen fertilizer application. 6. Any specific association between the plant characters and striped rice borer resistance could not be found. The variety Tongil even having large number of tillers, short plant height, large stem, broad leaf, etc, had still high preference of moths for oviposition, low preference of larvae for feeding, low damage, and relatively high antibiosis. 7. Resistance of the variety Tongil to the striped rice borers seemed to be associated with the low feeding preference and the relatively high antibiosis, not associated directly with the ovipositional preference.

• Korean journal of applied entomology
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• v.3
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• pp.41-44
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• 1964

1. This experiment was planned to compare the effectiveness of Diazinon granular and gammadol dust with the low toxic organophosphorus insecticides applied on the water-surface for the control of the rice stem borer, Chilo suppressalis Walker, in the 2 nd generation and to determine the proper timing of those insecticidal applications at Suwon, Korea, in 1964. 2. The hatching larvae from the eggs were inoculated on the rice plants in pots and insecticides were applied on the water-surface of pots at a given day intervals. The dose of insecticides used per pot was calculated from the 120g. as a actual ingredient per 10 a. The number of living larvae was observed at the 20 days later from the inoculation (as shown in Table 1.). 3. As shown in Table 2 and 3, there was highly significance between the chemicals and L.S.D. was 24.22. The best effectiveness was Diazinon granular and 2nd was gamma-dol dust. The organophosphorus emulsion concentrations used in this experiment were less effective than two other insecticides. Although there were some suspicious results according to the day intervals inoculated, the order of effectiveness was Diazinon>gamma-dol>Sumithion>EM>EPN> Cidial as the total moan. 4, As shown in Table 2 and 3, there was no significance between the timing of insecticidal applications, but, m the whole, Diazinon granular was most effective at a given day intervals in this experiment and gamma-dol also was effective at the day Plot inoculated. The proper timing of EPN, EM, and Cidial seemed to be at e day plot inoculated and that of Sumithion at the day plot before inoculation.

• Korean journal of applied entomology
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• v.21 no.4 s.53
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• pp.200-206
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• 1982

A computer simulation model was constructed to explore the phonology of the Striped Rice Borer, Chilo suppressalis (Walker), in Korea. The phenological system model based on the concept of distributed time delay was written in the computer program 'INSECT' and simulated with the estimated parameters of the effective day-degrees (DEL) and the order of time delay (K) for determining the validity of the system model. The accumulated emergence curves obtained from the phenological model were slightly different from the observed light trap data at the early and late stage of the moth emergence in 1978. The differences between observed and simulated $50\%$ emergence date were five to six days in the locations of Suweon and Chuncheon, while it was only two to three days in Iri, Daegu, Boseong, and Milyang. The phenological model should be further improved for simulation of field population changes by adding the information of the time delay process in each developmental stage, the age distribution of overwintered population, and the limiting factors of the borer mortality.

• Korean journal of applied entomology
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• v.10 no.2
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• pp.117-120
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• 1971

This experiment was carried out to obtain basic informations on the development in sterile-male technique of rice stem borer. The species considered is Chile suppressalis Walker. Different developmental stages of the insect namely; larval, pupae and adult were irradiated with $Co^{60}$ gamma ray. The results obtained were as follows: 1) A 1:1 sex ratio in the pupal stage was observed. 2) In the pupal stage sub-lethal dosages$(LD_{50})$ were 26 KR and 26.7 KR for female and male, respectively. 3) The total number of egg masses per female increased with the increasing gamma ray dosages and average number of eggs produced per female decreased in the cross between normal female and irradiated male. 4) The sterile dosage $(SD_{90})$ of the gamma ray irradiation showed 23 KR in the male. 5) The pupal stage is most convenient developmental stage for irradiation.

• Korean journal of applied entomology
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• v.20 no.1 s.46
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• pp.25-30
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• 1981

Mating confusion of the Striped Rice Borer with its synthetic sex pheromone, a mixture of (Z)-11-hexadecenal and (Z)-13-octadecenal in a ratio of 4.5 : 1, was estimated during the first and second generation in rice field near Suweon. The mixture was highly disruptive to pheromonal communication between males and females. The orientation behavior of male moths toward the females was confused at a dosage of 29.3g per 30a during the first generation and even at 33rr.g per $20m^3$ during the second generation.

• Korean journal of applied entomology
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• v.36 no.2
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• pp.141-144
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• 1997

Studies were conducted to investigate the incidense of insect pests in transplanted and direct seeded paddy fields in southern region of Korea. Population dencities of the rice green leafhopper (RGLH: Nephotettix cincticeps Uhler) and rice leaffolder (RLF: Cnaphalocroch medinalh Guenee) were higher in machine transplanted than in direct seeded, but the brown planthopper (BPH: Nilaparvata lugens Stal) and smaller brown planthopper (SBPH: Laodelphax striatellus Fallen) were abundant in direct seeded. However, no significant difference was found between machine transplanted and direct seeded fields in the incidense of rice stem borer (RSB: Chilo suppressalis Walker), whiteback planthopper (WBPH: Sogatella furcifera Horvath), and rice stem magot (RSM: C'hlorops oryzae Matsumura). Occurrence of rice key pests were affected more by transplanting time than other cultural practices. Later transplanting induced higher populations of BPH, WBPH, SBPH, RGLH. However, RSB and RLF caused higher damage in earlier transplanted paddy field.