• Korean journal of applied entomology
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• v.31 no.4
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• pp.480-485
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• 1992

Laboratory studies were done to evaluate the effects of diflubenzuron on embryonic and postembryonic development of Riptortus clavatus Thunberg. Diflubenzuron prevented egg hatch; younger eggs(O-12 h old) were 2 times as susceptible as older(48-60 h old) eggs, but embryos of both younger and older eggs developed normally. Susceptibility of nymphs to diflubenzuron decreased with each successive molt. Compared with the first instar, relative tolerance to diflubenzuron was 1.5 times for the second instar, 18.2 times for the third instar, 39. 4 times for the fourth ins tar and 42.4 times for the fifth instar. Even as low concentrations, diflubenzuron prevented significant numbers of third instar nymphs from developing to fourth and fifth instar nymphs or adults. Weight, longevity and fecundity of adults surviving treatment in the final (fifth) instar were also adversely affected.

• The Korean Journal of Pesticide Science
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• v.11 no.4
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• pp.299-304
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• 2007

Surveying, laboratory and field trial were performed to elucidate the causes of non-spinning syndrome of silkworm, Bombyx mori, abnormal symptoms of silkworm instars observed in certain sericultural fanning region. Mortality and growth of silkworm was still influenced by feeding the mulberry leaves sprayed with 10,000 fold diluted solution of standard spray of diflubenzuron WP (25%). Mortality and growth of silkworm fed with diflubenzuron-sprayed mulberry leaves with recommended spray solution were entirely affected even six weeks after spraying irrespective to the instars. Larval period of 5th instar and cocooning duration of silkworm was not affected in case 50m of buffer zone has maintained in near-by orchard field sprayed with diflubenzuron WP (25%). However, survival rate of pupae was not influenced in case 100 m of buffer zone has kept. Insect growth regulating insecticides were required to keep a certain distance of buffer zone when sprayed with water-diluted solution, 100 m from the application site at least in order to prevent contamination of the spraying drift by the chemicals.

• The Korean Journal of Pesticide Science
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• v.5 no.2
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• pp.62-66
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• 2001

The thirteen commercial insecticides to Lycoriella mali were investigated on their insecticidal activities and mycelial growth of two Letinula edodes strains. For the adults, insecticides showing over 95% insecticidal activity were chlorpyrifos-methyl, fenthion, fenitrothion, benfuracarb, furathiocarb and deltamethrin. For tile larvae, diflubenzuron and cyromazine showed over 90% insecticidal activity. Fenthion, benfuracarb, furathiocarb, deltamethrin, diflubenzuron and cyromazine did not affect the mycelial growth of L. edodes strain, in Imhyup 1 variety. And deltamethrin, diflubenzuron and cyromazine did not affect that in Sanlim-5. Insecticides showing over 80% residual effect for 14 days were benfuracarb to the adults and diflubenzuron and cyromazine to the larvae. Control effect of furathiocarb, fenthion, benfuracarb, deltamethrin, diflubenzuron and cyromazine against larvae of Lycoriella mali showed 90% ten days after application under sawdust cultivation. Among them, benfuracarb, fenthion and furathiocarb revealed excellent control effect against adults. These results indicate that benfuracarb, fenthion, and furathiocarb can be used for the control of Lycoriella mali in the field. However, further studies are needed on the effect of insecticides treatment oil fruit-body yield and chemical residue in the mushroom tissues.

• Journal of the Korean Chemical Society
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• v.34 no.1
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• pp.112-114
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• 1990

• The Korean Journal of Pesticide Science
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• v.6 no.2
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• pp.80-86
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• 2002

The activities against Frankliniella occidentalis adults collected at rose greenhouse of 40 commerical insecticides were investigated. Among them 9 insecticides showed over 80% mortality to the adults; chlorfenapyr, chlorpyrifos- methyl, emamectin benzoate, fenthion, fipronil, phenthoate, spinosad, chlorpyrifos+diflubenzuron and furathiocarb+diflubenzuron. Susceptibility of field populations collected from greenhouse rose at 5 locations in 2001 was evaluated against the 9 insecticides selected. There was considerable difference in susceptibility depending on the treated insecticides and the regions from which the populations were collected. Goyang and Gimhae populations showed lower $LC_{50}$(ppm) values then Imsil, Jincheon and Gaangjin populations to all the tested insecticides. The adults of all field populations showed lower $LC_{50}$ values less than 1 ppm to emamectin benzoate, fipronil and spinosad. From these results, we could recommend 5 insecticides, such as emamectin benzoate, fipronil, spinosad, chlorpyrifos+diflubenzuron and furathiocarb+diflubenzuron as effective ones to control the Frankliniella occidentalis field populations.

• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.137-146
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• 1998

Laboratory tests were carried out to evaluate the effect of several insecticides with insect growth regulator (IGR) properties on the larval development of housefly, Musca domestica, which was collected at a large pigpen in Hamyang, Gyeongnam, Korea in 1997. Commercial formulations of the chemicals were diluted with tap water into a range of concentrations, and mixed with larval media. In addition to the IGRs, imidacloprid 5% WP was tested, too. The IGRs treated at the 2nd instar stage induced higher larval mortalities than percentages of malformed pupae. The result were, however, opposite when the IGRs were treated at the 3rd instar stage. Overall mortality resulting from larval death and malformed pupae was dependent on concentration. Diflubenzuron, teflubenzuron, triflumuron, flufenoxuron, tebufenozide, and imidacloprid, treated to the 2nd instar larvae, showed mortality over 95 % at concentrations of 5 ppm, 3 ppm, 30 ppm, 5 ppm, over 1000 ppm, 1000 ppm, respectively. Higher concentrations were needed to get the same level. of mortality in the 3rd instar larvae as that in the 2nd larvae. Overall mortality over 95% at the 3rd instar could be get at concentrations of 100 ppm, 10 ppm, 300 ppm, 10 ppm of diflubenzuron, teflubenzuron, triflumuron, flufenoxuron, respectively. Tebufenozide (1,000 ppm) and imidacloprid (300 ppm) were less effective than the other chemicals, showing only 36.7% and 86.7% mortalities, respectively. The chemicals also affected pupal weight at high concentrations. Decrease of pupal weight was distinct at high concentrations of teflubenzuron, flufenoxuron, tebufenozide, imidacloprid. Diflubenzuron and triflumuron were less effective. From these results it could be concluded that the IGR insecticides can be used as control agents by interfering with moulting and pupation process of housefly, by reducing pupal weight which could be resulted in low fertility and less oviposition.

• Journal of Korean Society of Forest Science
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• v.94 no.4 s.161
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• pp.277-280
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• 2005

In order to prevent chestnuts from damage by the peach pyralid moth, Dichocrosis punctiferalis, a sprinkler system was installed on the chestnut orchard. Such a test was conducted at Yeoju-gun, Gyeonggi-do, Korea in 2002. Insecticides of fenitrothion 50% EC, x1,000 and diflubenzuron 25% Wp, x2,500 were sprayed at ten-day fifteen-day and twenty-day intervals during the period of D. punctiferalis adult occurrence by sprinkler system. The peach pyralid moths generally emerged for about 60 days from early July to early September, and peak emergence was 10 days from late July to early August. Damage rate of chestnuts were 0.9-4.0% on average with this crown insecticide spraying with diflubenzuron, while 30.4% when not treated. Control effectiveness of this insecticide spraying was 92%(86.7-97.0%). In conclusion, effectual times and number of insecticide application with sprinkle system against peach pyralid moth were from early July to late August and four or five times at ten or fifteen day intervals, respectively.

• The Korean Journal of Pesticide Science
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• v.8 no.4
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• pp.347-352
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• 2004

Susceptibility of Curculio sikkimensis adults to 39 commercial insecticides were evaluated by body dipping method, Among them sixteen insecticides of chlorpyrifos, fenitrothion, fiponil, phenthoate, benfuracarb, thiodicaib, carbosulfan, bifenthrin, cypermethrin, $\lambda$-cyhalothrin, deltamethrin, clothianidin, acetamiprid+diflubenzuron, etofenpox+diazinon, esfenvalerate+fenitrothion and furathiocarb +diflubenzuron showed 100% mortality. Insecticides with over 80% residual effect at 1 day after treatment were phenthoate, benfuracarb and thiodicarb (95.0, 82.5, and 85.0%, respectively). However, after that, it was dropped rapidly. Other insecticides showed low residual effect. In the control efficacy test on C. sikkimensis, insecticides with over 90% control values at 1 day after treatment were phenthoate, thiodicarb, fipronil, acetamiprid+bifenthrin and furathiocarb+diflubenzuron. However, all insecticides from 2 days after treatment were over 90%.

• Korean Journal of Plant Resources
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• v.19 no.1
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• pp.93-96
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• 2006

In order to prevent cones from being damaged by cone insects, Gravitarmata margarotana and Dioryctria abietella, sprinkler system was installed on the Pinus koraiensis Seed Orchard. Such a test was conducted at Chung-ju, Chungcheong buk-do, Korea in 2002. Insectides of Diflubenzuron 25% WP ${\times}2,500$ and Cyfluthrin 2%EC ${\times}\;1,000$ were sprayed at fifteen-day and twenty-day intervals during the period of insects adult occurrence by sprinkler system. The Gravitarmata margarotana generally emerged for about 53 days from middle April to early June, and peak emergence was 10 days from April 20 to April 30. Dioryctria abietella generally emerged for about 108 days from late April to early August, and peak emergence was 10 days from May 20 to May 30. Damage rate of cones were $8.7{\sim}9.7%$ and $10.9{\sim}12.7%$ on average with crown insecticide spraying with Cyfluthrin and Diflubenzuron, while 67.5% when not treated. Control effectiveness of this insecticide spraying was $85.6{\sim}87.1%$ and 83.9%와 81.2%, respectively. When it considers the forest environment, it is recommended diflubenzuron which is low toxic pesticide. In conclusion, effectual times and number of diflubenzuron 25% WP application with sprinkler system against cone insects were from early May through late August and six times at twenty-day interval.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.269-277
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• 2014

The multiclass pesticide multiresidue method for the simultaneous determination of diflubenzuron in agricultural products was conducted by using HPLC-UVD. The method was validated through the guidelines of linearity, specificity, limit of detection (LOD), limit of quantification (LOQ), accuracy and precision with pesticide-free spinach, Korean cabbage, eggplant, squash, sweet pepper, cucumber, Korean melon. The calibration curve of diflubenzuron was linear over the concentration range of 0.05-5 mg/kg with correlation coefficient of above 0.99999. The limit of detection and quantification was 0.008 and 0.02 mg/kg. Mean recoveries of diflubenzuron for each sample were 77.5-105.6%. Relative standard deviation (RSD) in recoveries were all less than 20%. The intra-day and inter-day precision (RSD) were 0.4-1.9% and 0.7-1.9%, respectively. The result of validation indicated that this method was accurate and rapid assay.