• Bulletin of the Korean Chemical Society
• /
• v.33 no.4
• /
• pp.1183-1189
• /
• 2012

The KOrea Insecticide Exposure Model (KOIEM) was developed to facilitate ecological risk-based management of Korean insecticides. KOIEM, applied as a multimedia fate model, evaluates water, soil, air, and vegetation compartments based on three water-body types (streams, ditches, and ponds). Deltamethrin, a pyrethroid insecticide, was used to evaluate and create the model parameters. After exposure of both the stream and the ditch to deltamethrin, the KOIEM-predicted concentrations and the observed levels were in agreement. The model was also evaluated using the accuracy factor (AF), which was 4.32 and 0.35 for the stream and ditch, respectively. Ecological risk assessment was also performed to evaluate the application of KOIEM for four popular South Korean insecticides (cypermethrin, deltamethrin, diazinon, and permethrin). Despite the insecticides having low PECs in water, their risk quotients were typically above 1.0. Thus, KOIEM modification would be required in further studies to account for spatial variation.

• The Korean Journal of Pesticide Science
• /
• v.15 no.3
• /
• pp.329-334
• /
• 2011

Insecticidal activity of 31 registered insecticides was tested against Metcalfa pruinosa adults. All experiments were conducted at the recommended concentration (ppm) of each insecticide. Among them, 16 insecticides from organophosphates (dichlorvos, fenitrothion, fenthion, methidathion, phenthoate), carbamates (methomyl), pyrethroids (${\alpha}$-cypemethrin, deltamethrin, fenpropathrin, ${\gamma}$-cyhalothrin), neonicotinoids (acetamiprid, clothianidin, dinotefuran, imidacloprid, thiamethoxam), and other (endosulfan) showed 100% mortality by spraying on the body of M. pruinosa adults. Dichlorvos, fenitrothion, fenthion, methidathion, phenthoate and endosulfan showed 100% mortality by plant-dipping method. The residual effect was showed 100% mortality in four insecticides (fenitrothion, fenthion, methidathion, phenthoate) at one day after treatment, and three insecticides (fenitrothion, methidathion, phenthoate) were showed the mortality of 90% at three days after treatment.

• YAKHAK HOEJI
• /
• v.45 no.6
• /
• pp.694-700
• /
• 2001

Synthetic pyrethroids are analysis of a natural chemical moiety, pyrethrin derived from the pyrethrum plant Chrysanthemum. The natural pyrethrin structure has been modified to be highly lipophilic and photostable, creating an effective pesticide and resulting in an increased presence in the environment. Worldwide, they are commonly used insecticides against ticks, mites, mosquitoes, and as treatment for human head lice and scabies. Therefore, human exposure to their compounds in extensive. Several studies on the effects of pyrethroids on thyroid hormone regulation, estrogen and androgen function have been reported and yet little has been done try assess their potential hormonal activities. Among humans, a pyrethroid compound was suggested to be the causal agent for gynecomastia in a group of Haitian men. The reports suggest that some pyrethroid compounds are capable of disrupting endocrine function. Therefore, we examined estrogenic/antiestrogenic potential of three pyrethroid insecticides, that is permethrin, allethrin and fenvalerate in human breast cancer cell and action mechanism mediated by the estrogen receptor. Fenvalerate showed weak estrogenic activity but aallethrin and permethrin showed no effect. In combination with high levels (10$^{-10}$ M, 10$^{-11}$ M) of 17$\beta$-estradiol and three synthetic pyrethroids inhibited cert proliferations in MCF7-BUS cell by 17$\beta$-estradiol. Whereas, fenvalerate increased cell proliferative activity at lower level of estradiol (10$^{-12}$ M, 10$^{-13}$ M). The relative affinities to the estrogen receptor were observed by allethrin and permethrin treatment, but not by fenvalerate. These results indicated that some of pyrethroid insecticides may modulate estrogen functions in human breast cancer cell. The action mechanisms of estrogen receptor mediated antiestrogenicity by allethrin and permethrin were postulated.

• Korean journal of applied entomology
• /
• v.23 no.3 s.60
• /
• pp.166-171
• /
• 1984

The present studies were conducted to investigate the relative toxicity of several insecticides to the rice insect pests and the predatious spider, Pirate subpiraticus. In laboratory test by topical application, BPMC and MIPC for the plant and leafhoppers were toxic to Nilaparvata lugens, but less toxic to Pirata subpiraticus. Other carbamate insecticides such as carbaryl, carbofuran, and MTMC showed highly toxic effect on P. subpiraticus as well as N. lugens. No organophosphates showed selective toxicity to P. subpiraticus. Thiocyclam, effective to Chilo suppressalis and Sesamia inferens, had highly good selective toxicity to P. subpiraticus. In case of insecticides for Nephotettix cincticeps, BPMC only had a little selective toxicity between N. cincticeps and P. subpiraticus. Organophosphate insecticides which had been reported to induce chemical resistance to N. cincticeps showed high $LD_{50}$ value to N. cincticeps. In pot trials, dust formulation was more toxic to P. subpiraticus than emulsifiable concentrate. It was more toxic to P. subpiraticus to increase number. of insecticide application.

• Korean journal of applied entomology
• /
• v.63 no.1
• /
• pp.13-23
• /
• 2024

Vespa velutina nigrithorax du Buysson, 1905 is the invaded species in Korea since 2003. Since its importance as the honey bee pest, beekeepers use insecticides to kill the adult and immature hornets. However, its legality and effectiveness has not been confirmed. This study investigated the susceptibility of insecticides commonly used to control hornets by beekeepers in Korea. Eight insecticides were tested on adult worker and larvae by topical or oral treatment. Adults showed more than 70% mortalities from Clothianidin, Dinotefuran, and Carbosulfan treatment within 30 minutes. Bifenthrin and Cartap hydrochloride showed relatively low toxicity. The median lethal dose (LD₅₀) for Clothianidin, Dinotefuran, and Carbosulfan was 0.29, 0.65, and 2.21 ㎍/bee, respectively. In larval feeding test where 5^th instar larvae were fed 3 times every 24 hours, the mortality began after second treatments. After 3rd treatments (72 h), all insecticides showed mortality more than 70%. The LD₅₀ values of Clothianidin, Dinotefuran, and Carbosulfan to V. velutina were approximately 10 to 100 times higher than those to honey bee, Apis mellifera. This study provides the basic information of those chemical toxicities to Vespa hornet and honey bees.

• The Korean Journal of Pesticide Science
• /
• v.20 no.1
• /
• pp.72-81
• /
• 2016

Feeding behaviors of the pear psylla, Cacopsylla pyricola, and their changing feeding behaviors were recorded and analyzed with an electrical penetration graph (EPG) analysis against 5 insecticides. And their mortality against insecticides were carried out in the laboratory. General feeding behavior patterns of C. pyricola were changed by insecticide treatments. Especially, the type and frequency of waveforms differently occurred depending on a sort of insecticides treated. Total duration of transition to waveform PE1 and phloem ingestion (waveform PE2) were significantly different between treatment and non-treatment of insecticides. When 5 different insecticides were treated on pear leaves, difference of feeding patterns were recorded. In case of treatment of benfuracarb, total duration of non-probes (waveform Np) was appeared higher than any other insecticide. However, when flonicamid and deltamethrin were treatment, total duration of stylet penetration (waveform PA) and xylem ingestion (waveform PG) were appeared higher than other insecticide, respectively. As results feeding behaviour of C. pyricola after treated insecticides with time-based consumed rate of C. pyricola, the rate of non-probe (waveform Np) was longer than start penetration (waveform PA), penetration and ingestion in parenchyma cells (waveform PC1+PC2), ingestion at phloem (waveform PD+PE1+PE2) and xylem (waveform PG). As result of direct spray treatment to C. pyricola, mortality of C. pyricola against imidacloprid was higher than any other insecticide on 24 hours after treatment. However, all of insecticides showed 100% mortality of after 48 hours. On the other hand, when 5 insecticides sprayed on the pear leaves and then C. pyricola located on the treated leaves, benfuracarb showed the most toxicity against C. pyricola among insecticides. These result was consistent with the EPG results that showed relatively longer total duration time of waveform Np (non-probes) by benfuracarb treatment.

• Korean journal of applied entomology
• /
• v.9 no.1
• /
• pp.25-32
• /
• 1970

This experiment was conducted to find out the simultaneous control effect of granulated insecticides on the several major rice insect pests in Korea. The granulated insecticides used were Terracur P$5\%$ (one of the phosphoric insecticides), Lebaycid $5\%$, and Sang-gamma (gamma-BHC) $6\%$. Those insecticides were broadcasted by hand on the paddy field at the ratio of 3kg. in June and 4kg. in August per 10 a, and the date of insecticidal application was based on the maximum moth occurrence of the rice stem borer in 1969. The rice insect pests tested in this study were rice stem borer (Chilo suppressalis W.), green rice leafhopper (Nephotettix bipunctatus cincticeps U.), smiller brown planthopper (Laodelphax striatellus F.), and white back planthopper (Sogotella furcifera H.). For the study of residual effectiveness of the insecticides, the rice stem borer larvae just hatched from the eggs were installed on the sheath of rice plants collected from the paddy field after insecticidal treatment, and the mortality was made at 48 hours after installation. High mortality was observed in Terracur P and Sang-gamma treatments and low mortality in Lebaycid treatment. The duration of residual effects giving about 50% mortality was about 14 days in Sang-gamma and about 6 days in Terracur P treatments. The study on the effectiveness of the insecticides to the rice stem borer in the paddy field was made by the number of dead blades and white heads of the rice plants injured by the larvae, and the number of survival larvae in the straws after crop harvest. The order of insecticidal effectiveness to the rice stem borer was Terracur P=Sang-gamm>Lebaycid. The study on the effectiveness of the insecticides to the leafhoppers and planthoppers in the paddy field was made by the population density by sweeping (5 times) at the given day intervals after treatments. Terracur P was highly effective for the control of the green rice leafhoppers and Lebaycid was moderately effective, but Sang-gamma seemed not to be effective. The effectiveness of the insecticides tested to the planthoppers was not clear, and it seemed to related with the low insect population density. Study on the determination of proper timing of insecticidal application was not also made clear, and it seemed to be short in the range of day intervals in the insecticidal application. For the study on the control effects of the rice insect pests, rice yield per 100 hills per plot was observed. There was no statistically significant difference among the treatments in rice yields, but the order of yield (Terracur P>Sang-gamma>Lebaycid>Control) was paralleled with the tends of control effects above mentioned. In a view point of simultaneous control of the rice stem borers and green rice leafhoppers by the application of granulated insecticides, Terracur P and Lebaycid were more effective than Sang-gamma which have been used.

• Environmental Analysis Health and Toxicology
• /
• v.2 no.1_2
• /
• pp.17-24
• /
• 1987

Changes in cholinesterase (ChE) activity, electrophoretic pattern of ChE and histopathologic state on the mice serum, brain and liver by administration of organophos-phorous insecticides were studied. The mice ChE activities on serum, brain and liver decreased by increasing of concentration and time both administration of malathion and DDVP, whereas on serum and brain the activities of the 7 days after administration decreased, and then presented the gradually slight recovery in course of time. The ChE on serum and liver showed many isozyme bands by polyacrylamide gel electrophoresis but several on brain. And isozyme bands disappeared and diffused by administration of organophosphorous insecticides and development of time. The mice liver with administration group of malathion on histopathologic test showed midzonal necrosis between central vein and portal area, and with administration group of DDVP mainly presented portal necrosis on location of potal area.

• Journal of Sericultural and Entomological Science
• /
• v.16 no.1
• /
• pp.93-100
• /
• 1974

It is reported that the useful larval characteristics and cocoon quality is damaged when the silkworm is fed on the insecticides contaminated mulberry leaf. The results obtained are as follow： 1) Mortality is growing when the silkworm is fed with the leaf treated with 1,000 folds insecticides and left for 25 days. 2) There are differences in the effects on the useful larval characteristics according to the insecticides, 3) Hernial larvae are brought about when the silkworm is fed with lebaycid stained leaf. 4) Malformed cocoon and abnormal silk is caused by the insecticide stained leaf feeding.

• Journal of Environmental Science International
• /
• v.12 no.8
• /
• pp.891-896
• /
• 2003

The objectives of this study wre to investigate the effects of two synthetic pyrethroids, bifenthrin(BF) and permethrin(PM), in runoff and to evaluate the effects of suspended solids (SS) in the transport of pyrethroid along the drainage channel. Monitoring of BF and PM was conducted with the runoffs as well as in sediments existing along the drainage channel at a nursery site located in southern California, USA. This study also suggests Best Management Practices (BMPs) to alleviage the pollution caused by heavy usage of pyrethroid insecticides at nursery sites. Due to a high affinity to solid particles of pyrethroid insecticides, the concentrations of BF and PM were proportional to the SS contents along the drainage channel. This study suggests that alleviation of pyrethroids existing in runoffs could be controlled by the removal of suspended solids in runoffs and potential implications of current drainage channels for mitigation of pesticides associated with runoffs.