• Journal of Forest and Environmental Science
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• v.36 no.3
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• pp.255-258
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• 2020

Pine wilt disease (PWD) caused by pine wood nematode (PWN), Bursaphelenchus xylophilus, which is transmitted by Monochamus alternatus and M. saltuarius, is a serious threat to coniferous forests in the Northern Hemisphere, including Korea. The efficacy of abamectin and emamectin benzoate for preventing the PWD in the field and its effect on the vectors Monochamus alternatus and M. saltuarius (Coleoptera: Cerambycidae) were evaluated. An experimental plot was delimited, of which consists of Japanese red pine (Pinus densiflora) forest in South Korea, and trunk injection trials were made with abamectin and emamectin benzoate. Branches of each tree were collected, and are subsequently subjected to the analysis of residues for both nematicides. Results obtained in this study showed that abamectin and emamectin benzoate showed over 90% mortality at the recommended concentration after 6 days and 8 days, respectively. Consequently, it was found that both insecticides have a higher effect on the susceptibility and persistence of two vectors of PWD, M. alternatus and M. saltuarius feeding on branches of the trees, and its application by trunk injection is confirmed as an option for pine wilt disease management programs in Korea.

• Korean journal of applied entomology
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• v.34 no.4
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• pp.360-367
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• 1995

The relative toxicity of abamectin was assessed to the predatory mite Amblyseius womersleyi Schicha and to dicofol-resistant and -susceptible twospotted spider mite (TSM) Tetranychus urticae Koch in the laboratory. Abamectin was much les toxic to the predator than to the spider mite. At 0.12 and 0.6 ppm, all TSM adult females of the tow strains were killed within 48 h after dipping n the solutions. The lower concentrations (0.06 and 0.012 ppm) killed more than 77% of TSM female adults of the two strains at 120 h after treatment. However, abmectin did not significantly affect the survival and mobility of A. womersleyi female adults at a concentration of 0.12 ppm but the mortality was slightly increased up to 20~23% at 0.6 and 6 ppm. Abamectin did not significantly affect hatchability of one-day old TSM eggs at 0.06~0.6 ppm. The Four-day old eggs were much more susceptible to abamectin than one-day old eggs were. Within 0.006-6 ppm, abamectin did not affect the hatchability of A. womersleyi eggs and the development of resulting immature predators. When the predator female adults were dipped in 0.6 and 0.12 ppm solution, their reproduction was not affected, but at 6 ppm it was decreased by 35%. However, the reproduction of TSM reduced significantly at concentrations between 0.006 and 0.6 ppm. The differential toxicity of abamectin between TSM and the predator could be of practical importance in managing spider mite populations in the field. Abamectin at selective sublethal concentrations (i.e., 0.012~0.06 ppm) could be of value in adjusting predator/prey ratios in integrated management of spider mites.

• 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.6 no.4
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• pp.244-249
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• 2002

This study was carried out to investigate the toxicities of 22 insecticides to Dichromothrips smithi. Insecticidal activity was evaluated by testing systemic action and residual effect in laboratory. All insecticides used in this study did not affect on the egg of D. smithi, although organophosphates such as fenitrothion, fenthion, methidathion, phenthoate, and phenthoate+ethofenprox suppressed the egg hatchability completely. On D. smithi larva fenitrothion, fenthion, methidathion, phenthoate, ethofenprox, thiamethoxam, abamectin, chlorfenapyr, emamectin benzoate, fipronil, spinosad, and phenthoate+ethofenprox showed 100% insecticidal activity. On D. smithi adult fenitrothion, fenthion, methidathion, phenthoate, ethofenprox, abamectin, emamectin benzoate, fipronil, spinosad, and phenthoate+ethofenprox showed 100% insecticidal activity. Root-uptake systemic effects of phenthoate on the larva of D. smithi was 43.3%. Whereas, systemic effect of other insecticides was less than 20%. Insecticide with more than 80% residual effect for 7 days after treatment were fenitrothion, fenthion, methidathion, phenthoate, ethofenprox, emamectin benzoate, fipronil, spinosad, and phenthoate.

• Korean journal of applied entomology
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• v.59 no.4
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• pp.399-405
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• 2020

The susceptibility and control efficacy evaluated for 10 kinds of commercialized acaricides, to obtain basic data for the chemical control strategy of Two-spotted spider mite (Tetranychus urticae) in Hooker chives. The susceptibility evaluation of T. urticae female adults, Abamectin EC, Pyflubumide SC, Cyenopyrafen SC, and Acequinocyl SC showed 100% mortality, and Pyflubumide SC, Acequinocyl SC, and Etoxazole SC showed zero hatching rate, i.e. 100% mortality of eggs. As a result of evaluating the field test for Abamectin EC, Pyflubumide SC, Cyenopyrafen SC, Cyflumetofen SC, and Acequinocyl SC, which had excellent mortality in the laboratory conditions, all treatment plots showed more than 90.3% control efficiency on after 7 days.

• The Plant Pathology Journal
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• v.39 no.3
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• pp.290-302
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• 2023

Abamectin offers great protection against Bursaphelenchus xylophilus, a well-known devastating pathogen of pine tree stands. Trunk injection of nematicides is currently the most preferred method of control. This study aimed to evaluate the potency of the commonly used formulations of abamectin against B. xylophilus. Twenty-one formulations of abamectin were evaluated by comparing their sublethal toxicities and reproduction inhibition potentials against B. xylophilus. Nematodes were treated with diluted formulation concentrations in multi-well culture plates. And, populations preexposed to pre-determined concentrations of the formulations were inoculated onto Botrytis cinerea culture, and in pine twig cuttings. Potency was contrastingly different among formulations, with LC₉₅ of 0.00285 and 0.39462 mg/ml for the most, and the least potent formulation, respectively. Paralysis generally occurred at an application dose of 0.06 ㎍/ml or higher, and formulations with high sublethal toxicities caused significant paralysis levels at the tested doses, albeit the variations. Nematode reproduction was evident at lower doses of 0.00053-0.0006 ㎍/ml both on Botrytis cinerea and pine twigs, with significant variations among formulations. Thus, the study highlighted the inconsistencies in the potency of similar product formulations with the same active ingredient concentration against the target organism, and the need to analyze the potential antagonistic effects of the additives used in formulations.

• Korean Journal of Veterinary Research
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• v.38 no.3
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• pp.589-594
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• 1998

The in vitro screening tests against the in vitro cultivated $L_3$ of Ascaris suum (in vitro $L_3$), which were cultivated from the embryonated egg to third-stage larva on 7 days in culture(DIC) and the in vivo rat's lung-derived $L_3$ of Ascaris suum (in vivo $L_3$), which were recovered from the lungs of rat on 7 days after infection, carried out in order to compare the anthelmintic efficacy of in vitro $L_3$ and that of in vivo $L_3$ in RPMI medium 1640 with 5% bovine calf serum. And also a screening test of efficacy against adult worms of Trichuris suis performed. The efficacies of screening tests were as follows : 1. The screening efficacies of abamectin and ivermectin against the in vitro $L_3$ were all 100% at the 10ppm concentration in RPMI medium 1640 on 5 DIC. 2. The screening efficacies of abamectin and ivermectin against the in vivo $L_3$ were all 100% at the 20ppm on 5 DIC or at 40ppm on 3 DIC. 3. The screening efficacies of abamectin and ivermectin against the adult worms of Trichuris suis were all 100% at 20ppm on 4 DIC. And therefore, the in vitro cultivated $L_3$ of Ascaris suum were used in the screening test as well as the in vivo rat's lung-derived $L_3$ of Ascaris suum. And also the adult worms such as Trichuris suis and filaroids which is small size and difficult to cultivate to vitro, were used in the screening test in vitro.

• Korean journal of applied entomology
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• v.52 no.3
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• pp.215-225
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• 2013

To assess the efficacy of nematicides for the control of plant-parasitic nematodes in fruit and vegetables fields, soil samples were collected from a cucumber field at Gongju; from strawberry fields at Buyeo, Nonsan, and Jinju; and from a melon field at Gocksung in Jeonnam Province, Korea. Plant-parasitic nematodes were separated from each soil sample and identified. The susceptibilities of the nematodes to abamectin 1.68% SC, cadusafos 3% GR, dazomet 98% GR, fosthiazate 30% SL and BA12011 SL were examined under laboratory and field conditions. The average population density of plant-parasitic nematodes was generally reduced after the treatment with nematicides; however, there was increase in the population of Pratylenchus spp. in soil after treatment with fosthiazate at Buyeo and Gocksung. Furthermore, there were increased populations following treatment with abamectin, cadusafos, and dazomet at Gocksung. The control effects of BA12011 treatment on plant-parasitic nematodes were confirmed to be similar to those of the other 4 nematicides evaluated, although its control effect was higher than that of fosthiazate in cucumber-growing soil at Gongju. The effects of nematicide treatment on egg mass formation in each of the collected soils differed according to the region of soil origin. Abamectin was effective in reducing the degree of egg mass formation in Buyeo and Jinju soil, whereas BA12011 was effective in Nonsan and Gocksung soil. Dazomet was found to inhibit egg mass formation in Gongju soil. To evaluate the effect of the newly developed nematicide, BA12011, experiments were conducted in a cucumber-growing greenhouse. The average population densities of Meloidogyne spp., Pratylenchus spp., and Helicotylenchus spp. after the first treatment were reduced to a greater extent than after the second treatment. It is thus suggested that early nematicide treatment is important for effective control of plant-parasitic nematodes.

• The Korean Journal of Pesticide Science
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• v.12 no.4
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• pp.382-390
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• 2008

This study was performed to evaluate the acute toxicity and residual toxicity of the 69 kinds of agrochemicals (41 insecticides, 18 fungicides, and 10 acaricides) against honeybee, Apis mellifera and bumblebee, Bombus terrestris. According to the IOBC standard, the toxicity showed below 30% was classified as non-toxic. Among 41 insecticides, five insecticides (acetamiprid, chlorfenapyr, thiacloprid, milbemectin, and buprofezin+amitraz) against the honeybee; eight insecticides (methomyl, thiodicarb, acetamiprid, chlorfenapyr, thiacloprid, abamectin, spino sad, buprofezin+amitraz) against the bumblebee did not show any toxic effect. Therefore, it thought to being safe. Other 18 fungicides and 10 acaricides were safe against the honeybee and bumblebee. In residual toxicity against the honeybee, eight insecticides (dichlorvos, methomyl, imidachlorprid, emamectin benzoate, spinosad, cartap hydrochloride, chlorfenapyr, and endosulfan) among 41 insecticides tested were safe at three days after treatment; however, sixteen insecticides (dimethoate, fenitrothion, fenthion, methidathion, phenthoate, pyraclofos, fenpropathrin, clothianidin, dinotefuran, thiamethoxam, abamectin, acetamiprid+ethofenprox, acetamiprid+indoxacarb, bifenthrin+imidacloprid, ethofenprox+phenthoate, imidacloprid+methiocarb) still remain high toxicity at eleven days after treatment. Against the bumblebee, residual toxicity showed as safe in seven insecticides (dimethoate, methidation, a-cypermethion, ethofenprox, indoxcarb, chlorpyrifos+a-cypennethrin, esfenvalerate+fenitrochion) at three days after treatment; however, eight insecticides (fenitrothion, pyraclofos, clothianidin, fipronil, acetamiprid+ethofenprox, chlorpyrifos+bifenthrin, ethofenprox+phenthoate, imidacloprid+methiocarb) still showed high toxicity at seven days after treatment. From above results, it will be useful information to select insecticides being safe and effective against the honeybee and bumblebee.

• The Korean Journal of Pesticide Science
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• v.17 no.1
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• pp.72-75
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• 2013

This study was performed to investigate the susceptibility and control efficacy of 27 registered insecticides against pear psylla, Cacopsylla pyricola in laboratory and field (Jincheon). Mortality of 3rd instar of C. pyricola was higher treated with pyrifluquinazon WG (97.7%), flonicamid WG (94.7%), abamectin EC (92.8%), and acetamiprid+buprofezin EC (86.8%) sprayed with field recommended concentration using a prayer in laboratory. These four insecticides also showed control effects of > 90% at 5 days after treatment in field.