• Korean Journal of Soil Science and Fertilizer
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• v.26 no.4
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• pp.299-303
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• 1993

This study was conducted to evaluate the boron phyto-toxicity on soybean grown on the potted soil amended with 20% by weight of fly ash with high and medium boron contents Of two years experiment, the first year experiment observed the direct effect and the 2nd year experiment the residual effect. Soybean growth and yield were normal with incorporation of 20% fly ash with normol B content. With high B flyash, however, the performance of soybean was poor due to B toxicity. Therefore, it is suggested that in determining the application rate of flyash, B content should be taken in account.

• Korean journal of applied entomology
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• v.41 no.4
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• pp.285-292
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• 2002

These studies were carried out to investigate the fumigant toxicity, the contact toxicity and the ovipositional repellency of 25 monoterpenoids against oak longicorn beetle adults, Moechotypa diphysis. Monoterpenoids with 100% of fumigant toxicity were 1, 8-cinehone, fenchone, pulegone and (equation omitted)-terpinene at 20 (equation omitted)/954 ml (air) concentration, pulegone and (equation omitted)-terpinen at 10 (equation omitted)/954 ml (air) concentration, pulegone at 5 (equation omitted)/954 ml (air) concentration. Most monoterpenoids showed low or no contact toxicity but only pulegone showed about 70% mortality. Some monoterpenoids which had repellency to female adults with Y-tube olfactometer were bornylacetate, carvacrol, 1, 8-cineole and menthol at 1 (equation omitted) dose, while citronellol showed attractant response. Carveol, geraniol and perillyl alcohol of 25 monoterpenoids showed ovipoistional repellency of 82.1%, 78.3%, 87.5%, respectively, at the concentration of 1,000 ppm in the laboratory condition. In the field, the result tested with three monoterpenoids indicated that geraniol was the most effective one at the concentration of 10,000ppm and 1,000 ppm, but residual effect wasn't found.

• Korean journal of applied entomology
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• v.61 no.4
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• pp.519-528
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• 2022

The western flower thrips, Frankliniella occidentalis, infests the hot pepper cultivated in greenhouses and has been considered to be controlled by a natural enemy, Orius laevigatus. However, sporadic outbreaks of the thrips due to fast population growth occasionally need chemical insecticide treatments. This study was designed to develop an optimal integrated pest management (IPM) by using selective insecticides along with a safe re-introduction technique of the natural enemy after the chemical insecticide treatment. First, chemical insecticides were screened to select the high toxic commercial products against F. occidentalis. Five insecticides containing active components (pyriproxyfen+spinetoram, abamectin, spinosad, acetamiprid, and chlorpyrifos) were selected among 17 commercial products. These five selected insecticides gave different toxic properties to the natural enemy, O. laevigatus. Especially, abamectin and spinetoram gave relatively low toxicity to the natural enemy compared to organophosphate or neonicotinoid. Furthermore, the five selected insecticides were assessed in their residual toxicities against O. laevigatus. Organophosphate and neonicotinoid insecticides showed relatively longer residual toxicity compared to abamectin and spinosads. Indeed, abamectin or spinetoram did not give any significant toxicity to O. laevigatus after 3 days post-treatment. These residual effects were further supported by the assessment of the chemical residue analysis of the insecticides using LC-MS/MS. These results suggest an IPM technology: (1) chemical treatment of abamectin or spinetoram against sporadic outbreaks of F. occidentalis infesting hot pepper and (2) re-introduction of O. laevigatus to the crops after 3 days post-treatment to depress the equilibrium density below an economic injury level.

• The Korean Journal of Pesticide Science
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• v.12 no.3
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• pp.229-235
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• 2008

Lack of honey bee toxicity data for most pesticide products used for strawberry restricts to predict the adverse effects to foraging honey bee after treatment of pesticide in plastic house. This study was conducted to evaluate the actual risk of worker honey bees (Apis mellifera L.) through acute contact toxicity test, acute oral toxicity test and toxicity of residues on foliage test with 21 pesticide products. The mortality of honeybee sprayed with 6 pesticides including dichlofluanid WP showed significantly different from control at recommended application rate in acute contact toxicity test at 24 hours after treatment. Fenpropathrin EC and milbemectin EC treatment groups showed more than 25% mortalities at recommended application rate in acute oral toxicity test. In toxicity of residues on foliage test, only fenpropathrin EC treatment group showed more than 25% mortalities at 10 days after treatment at recommended application rate. It was concluded that the most toxic route to exposure for honey bee is direct contact exposure to sprayed pesticides. Safety interval for honey bee was established by concerning the results of these tests.

• The Korean Journal of Pesticide Science
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• v.4 no.4
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• pp.48-55
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• 2000

This study examined how does farm producers and urban consumers recognize the toxicity of pesticides application to agricultural production. The survey was carried out with quesuonnaires, and found tile fellowing results. The 60% of the total respondents in urban residents acknowledged that it is necessary for farming to apply pesticides. Nevertheless, they think that pesticides application have excessively been done more than necessary, and they would cause the problem of agrochemical-residual in agricultural products. They preferred to the crops produced by organic-farming. But they do not believe that the organic crops are pure one that pesticides are not applied at all. They thought that pesticides remained in the crops and they cause a chronic toxicity and cancer, though their degree of causing cancer would not be high. The other hand, farmers among the total respondents expressed that pesticides are absolutely needed to farming. However, about half of the total farmers' respondents did not follow the recommended guide line for proper use of pesticides and applied its double amount of the recommended dose. The most of farmers thought that the applied pesticides would be persisted into the crops. The 69 % of the total respondents did not know that crops over MRL(Maximum Residue Limit) of pesticides must be discarded and tile farmer who distributed the crops over MRL of pesticides have to pay some kind of penalty.

• Korean journal of applied entomology
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• v.53 no.4
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• pp.457-460
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• 2014

Toxicity of several insecticides was tested against the brown marmorated stink bug, Halyomorpha halys (Hemiptera: Pentatomidae), and adult Gymnosoma rotundatum (Diptera: Tachinidae) in a sweet persimmon orchard. H. halys was captured using black light traps and G. rotundatum adults were collected using sticky traps lured with an aggregation pheromone, methyl-(E,E,Z)-2,4,6-decatrienoate of Plautia stali. Five insecticides, namely, bifenthrin 2 WP, buprofenzine+dinotefuran (20+15) WP, clothianidin 8 SC, dinotefuran 10 WP, and thiamethoxam 10 WP, were moderately toxic to G. rotundatum, resulting in 55.3% to 74.3% mortality. Bifenthrin 2 WP caused 93.1% mortality at 72 h within cages as a residual toxicity, and others caused varied mortalities.

• Korean journal of applied entomology
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• v.57 no.3
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• pp.221-231
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• 2018

The susceptibility of the western flower thrips, Frankliniella occidentalis and garden thrips, Frankliniella intonsa was evaluated using 51 commercial insecticides. 15 kinds of insecticides which showed more than 90% mortality against both thrips, F. occidentalis and F. intonsa was selected. Many active ingredients were misused and abused in commercial mixture formulation insecticides. Since the F. intonsa was more susceptible than F. occidentalis, it was considered that both thrips can be controlled by insecticides that showed insecticidal activity on the F. occidentalis. Lethal time ($LT_{50}$ and $LT_{95}$), systemic toxicity and residual toxicity of selected insecticides were compared. Both chlorpyrifos WP and chlorpyrifos + diflubenzuron WP revealed the fastest toxicity within 2 h ($LT_{95}$), while spinetoram WG revealed the slowest toxicity as 62.3 h ($LT_{95}$). Chlorfenapyr SC showed toxicity at foliar and drenching application while spinetoram WG was toxic only in foliar application. Chlorfenapyr SC showed residual effect at 3, 5, 7, 10, 15 days after treatment and both benfuracarb WG and chlorpyrifos WP showed residual effect at 3 days after treatment. As a result of treatment of selected insecticides for field population of F. occidentalis, the population collected from horticultural crops showed lower susceptibility than the population collected from vegetable crops.

• Food Science of Animal Resources
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• v.42 no.4
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• pp.712-722
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• 2022

In this study, we investigated the residual properties of tebuconazole-treated pigs. Twenty pigs were treated with different concentrations (0.25, 1.25, 2.5, 12.5, and 25 mg/kg bw/d) of tebuconazole for 28 d. Blood biochemistry, histology, and residual levels were analyzed using the VetTest analyzer, Masson's trichrome staining kit, and liquid chromatography-mass spectrometry, respectively. The final body weights were not significantly different between the control and treatment groups. Alkaline phosphatase, blood urea nitrogen, cholesterol, and gamma-glutamyl transpeptidase levels were significantly different from those of the control after exposure for 14 d. However, alanine aminotransferase levels showed changes only after exposure to pesticides for 28 d. The biochemical parameters were separated during the experimental period (14 d versus 28 d) by principal component analysis. Based on variable importance plots, blood urea nitrogen/creatinine ratio, blood urea nitrogen, glucose, and gamma-glutamyl transpeptidase are candidate biomarkers for tebuconazole exposure. The residual levels were observed at T4 (12.5 mg/kg bw/d) and T5 (25 mg/kg bw/d) in the liver and fat tissues, respectively. Fibrosis increased in the liver, kidney, and fat tissues, depending on the tebuconazole concentration. In conclusion, the residue limits of tebuconazole and the physiological changes caused by dietary tebuconazole in pigs provide important information for establishing maximum residue limits of pork and pork products.

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.1
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• pp.13-22
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• 2002

Stink bug, Canthecona furcellatta (Hemiptera: Pentatomidae), is an important predator of silkworm larvae. Nymphs and adult attack the early stage silkworm larvae and causes about 10-15 per cent loss to silk industry. Synthetic organic pesticides has tremendous impact on minimizing the pest population but repeated and frequent use has created problems of residual toxicity, development of resistance to insecticides, pest resurgence and out break, phyto-toxicity and hazards to non target species and beneficial organism. Silkworms are very sensitive to pesticides; therefore, attempt has made to control the bug population through introduction of its native natural enemies in the silkworm-rearing field. Biological control has tremendous scope in sericulture because it is eco-friendly in nature and non-harmful farmers. Native natural enemies have been screened. Psix striaticeps, Trissolcus spp. and Telenomus spp. have been recorded as the most potential parasitoid against pentatomid bug. Life cycle, sex ratio and other various attributes of the par-asitoids have been recorded. The parasitization potential of the parasitoid is very high and they have the ability to discriminate between parasitized and unpar-asitized host. Mass propopagation technique under laboratory condition has been standaydized.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.5
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• pp.603-610
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• 2013

According to industrialization, increased toxic chemicals discharge has been causing water pollution. Especially domestic sewage is a major source of water pollution. Sixty percent of the total wastewater discharged is domestic sewage. Self-purification capacity of rivers and streams is drastically reduced by the emission of domestic sewage, industrial wastewater and livestock wastewater. Although domestic sewage is managed by implementing standards and regulations, toxicity effect of domestic sewage to humans and the environment is not yet clearly understood. In this study, by using daphnia magna, the ecotoxicity of domestic swage was assessed. Cl, Cu, Pb, COD, T-N, DO, pH and residual chlorine were investigated as background concentrations. The experiments were conducted with water samples obtained from three local sewage treatment plants. The experiment results indicated that higher level of toxicity corresponds to the higher pollution concentrations. The higher level of combinations of background concentrations such as heavy metals leads to the worse ecotoxicity. Especially, the Cu concentration affects the TU value.