• The Korean Journal of Pesticide Science
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• v.11 no.4
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• pp.238-245
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• 2007

This survey was performed to elucidate whether pesticide can cause the non-spinning syndrome of silkworm, Bombyx mori in Yecheon and Sangju 2002. We primarily focused to Insect Growth Regulator Pesticides(IGR) used in that areas. In the result of the survey to the retail pesticide store at Yecheon and Sangju, seven pesticides of the total 12 IGR pesticides sold were used during spring sericuitural season. 7 pesticides might effect on silkworm in consideration of possibility of exposure according to the characteristics of used amount, spray drift, volatility and treatment time. Five chitin synthesis inhibitor involving diflubenzuron of 7 IGR pesticides were known as very toxic to silkwork after exposure by skin and feeding but no non-spinning syndrome was observed from several papers. Methoxyfenozide and tebufenozide also has used at sericultural season, but are ecdysone agonist. One of the most feasible suspect of non IGR pesticide, was molinate in consideration of its volatility property and wide spread use in the sericultural area. But it's symptom after exposure of molinate was not the same as the non-spinning syndrome broke out at the sericultural farm in Yecheon and Sangju.

• 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.

• Journal of Sericultural and Entomological Science
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• v.46 no.2
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• pp.58-64
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• 2004

The current study was performed to clarify the pupation disorder symptoms in silkworm which herbicide, molinate has been regarded as a causal origin. Molinate residues in mulberry leaves was monitored in major rearing area of silkworm; Yeacheon, Sangju and Namwon. Detected range of the molinate in mulberry leaves was 0.002 to 0.013 mg/kg and detection frequency was 30.0 to 81.8%. Molinate concentration in the air of mulberry tree growing area was $0.004\;{\mu}g/m^3$. Water diluted solution of molinate at the concentration of 1, 10, 100 mg/l gave no abnormal symptoms in silkworm irrespective of spraying to silkworm or spiking to diet. Exposing the silkworm to the air containing 250, 2,500, and $10,000\;{\mu}g/m^3$ also revealed no abnormal symptom. These results illustrated that the abnormal growth of silkworm encountered in the field was not caused by pesticide contamination.