• The Korean Journal of Pesticide Science
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• v.17 no.2
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• pp.77-83
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• 2013

This study was performed to investigate pre-harvest residue limit (PHRL) in amaranth, to estimate biological half-life of emamectin benzoate and identify the characteristics of the residue. Pesticides of standard and double appplication rate, were sprayed once on amaranth at 0, 1, 2, 3, 5, 7, 10, 14 days before harvest. Amaranth sample was extracted with acetonitrile and partitioned with dichloromethane, and pesticide residues were determined with LC/MS/MS. The limit of detection of emamectin benzoate was 0.01 mg/kg. Recoveries of emamectin benzoate ($B_{1a}$, $B_{1b}$) at two fortification levels of 0.1 and 0.5 mg/kg, $B_{1a}$ were $93.3{\pm}0.7%$ and $93.2{\pm}7.7%$, $B_{1b}$ were $106.6{\pm}1.9%$ and $80.5{\pm}6.6%$, respectively. The biological half-lives of emamectin benzoate were about 2.0 days at standard application rate and 1.7 days at double application rate, respectively. The PHRL of emamectin benzoate were recommended as 0.84 mg/kg for 10 days before harvest.

• The Korean Journal of Pesticide Science
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• v.12 no.4
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• pp.397-402
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• 2008

This study was performed to investigate the correlation between changes of feeding behavior of Bemisia tabaci and residual effect of two insecticides, emamectin benzoate and pyridaben, using EPG technique. Waveforms such as non-probe time and total duration of phloem phase of B. tabaci were recorded during three hours using EPG. Relationship between non-probe time and the change of residual effect of two insecticides correlated with more pyridaben than emamectin benzoate. In the relationship between phloem phase time and those of residual effect, emamectin benzoate was more correlated than pyridaben. These results show that the change of feeding behavior of B. tabaci is correlated with the change of residual effect of two insecticides.

• The Korean Journal of Pesticide Science
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• v.5 no.1
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• pp.46-54
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• 2001

These studies were carried out to investigate the toxicities of 33 registered insecticide to the American serpentine leafminer, Liriomyza trifolii. Insecticidal activities were evaluated by testing systemic action and residual effect in the laboratory, and control efficacy and phytotoxicity in the greenhouse. All insecticides used in this study did not effect on the egg of L. trifolii, although spinosad showed 70% of egg-hatch suppression. For L. trifolii larvae ($2{\sim}3$ instar), the insecticides with over 95% of insecticidal activity were abamectin, cartap, cyromazine, emamectin benzoate, diflubenzuron + chlorpyrifos. The Insecticide what showed over 90% of insecticidal activity or neonate larvae were abamectin, cartap, emamectin benzoate, diflubenzuron + chlorpyrifos and milbemectin. Only cartap + buprofezin showed over 95% insecticidal activity against L. trifolii pupae. Almost insecticides used in this study little or not effected on the adult of L. trifolii. Emamectin benzoate and milbemectin showed moderate foliar systemic effects on eggs of L. trifolii (53.3, 47.9%, respectively). However, other insecticides showed little systemic effect. For larvae and adults, all insecticides showed low systemic effects. Insecticides with over 90% residual effect for 10 days were abamectin, emamectin benzoate and milbemectin (91.4, 90.4, 91.9%, respectively). In the control efficacy test on L. trifolii 90% of control values were obtained at 14th day after treatment of the insecticides including abamectin, cyromazine, emamectin benzoate and milbemectin. Cartap and cartap + buprofezin showed slight phytotoxicity on kidney bean leaf, however, other insecticides showed no phytotoxic effects. These results indicate that abamectin, emamectin benzoate and milbemectin can be used for tile control of L. trifolii in field.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.267-274
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• 2009

This study was carried out to select effective preventive pesticides against pine wilt disease caused by pinewood nematode (PWN), Bursaphelenchus xylophilus on trunk injection. 1,000 fold aquatic solution of abamectin 1.8% EC and emamectin benzoate 2.15% EC were lower mortality (7.3% and 8.3% respectively) against PWN on 1 day after treatment. However effects of abamectin 1.8% EC, emamectin benzoate 2.15% EC, fosthiazate 30% SL and fenitrothion 30% SL were inhibited the reproduction of PWN over 99.6% in Botrytis cineria media. Effect of trunk injection of abamectin 1.8% EC and emamectin benzoate 2.15% EC at the rate of $10\;m{\ell}$ per 10 cm in diameter of breast height (DBH) on mortality of Japanese black pine, Pinus thungergii by inoculated PWN was 0% and 3.3%, respectively at the applied year however when injection of fosthiazate 30% SL were treated with the rate of $5\;m{\ell}$ per 10 cm tree DBH, mortality of tree was 63.3%. Abamectin 1.8% EC and emamectin benzoate 2.15% EC was showed high preventive efficacy representing >90% against PWN at the following year. PWN preventing efficacy of trunk injection was lower in naturally occurred area (mortality of pine tree in control was 11.7% at the first year) of PWN than artificially infected site (mortality of pine tree in control was >76.7% at the first year), PWN preventing efficacy of trunk injection of abamectin 1.8% EC and emamectin benzoate 2.15% EC at the rate of $10\;m{\ell}$ per 10 cm in DBH was 91.5% and 82.9%, respectively, at the applied year and 89.5% and 82.6% respectively at the following year in PWN naturally occurred site. Control efficacy by trunk injection of abamectin 1.8% EC and emamectin benzoate 2.15% EC was more higher in 10 fold dilution with 10 fold high amount of aquatic solution than no dilution with 10 fold less amount of aquatic solution. The preventive effect of trunk injection of abamectin 1.8% EC and emamectin benzoate 2.15% EC at the rate of $5\;m{\ell}$ per 10 cm in DBH was showed 100% at the applied year in PWN inoculated tree.

• The Korean Journal of Pesticide Science
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• v.10 no.4
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• pp.329-334
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• 2006

Susceptibility of American serpentine leafminer, Liriomyza trifolii, to four insecticides (abamectin, ememectin benzoate, spinosad and milbemectin) was tested in the laboratory. All insecticides showed high mortality on the egg and larval stage, but on pupa and adult. Oviposition was 100% suppressed by abamectin, emamectin benzoate and spinosad, and 85% by milbemectin. The three insecticides except milbemectin inhibited greatly the feeding activity of adults. Adult longevity was reduced (0.8-1.4 days) by the tree insecticides except milbemectin, in comparison with 5.5 days in control. Abamectin, emamectin benzoate and spinosad were effective on oviposition until 7 days after treatment, but milbemetin was not.

• 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.

• The Korean Journal of Pesticide Science
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• v.12 no.4
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• pp.363-367
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• 2008

Abamectin 1.8% EC and emamectin benzoate 2.15% were evaluated the simultaneous control effect of both insect pests on black pine (Pinus thunbergii) against Thecodiplosis japonensis and Matsucoccus thunbergianae. Abamectin 1.8% EC was highly effective against T. japonensis and M thunbergianae, however, emamectin benzoate was highly effective against only M. thunbergianae when abamectin and emamectin benzoate were applied through trunk injection against T. japonensis and M thunbergianae at the rate of 1 ml per cm in diameter of breast height. The rate of gall formation of T. japonensis was 0% at the applied year, but 85% at the following year. However, the rate of gall formation was over 90% at the treatment of emamectin benzoate showing no difference compared with control. Abamectin 1.8% EC and emamectin benzoate 2.15% showed high control efficacy representing 89.1% and 91.4% against M. thunbergiana, respectively.

• 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.

• 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.17 no.4
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• pp.363-370
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• 2013

Susceptibility of each developmental stage of Phthorimaea operculella (Lepidoptera: Gelechiidae) were investigated using 16 insecticides which are available in the market in Korea. For the eggs and pupae, only spinosad showed a 71.1% inhibition rate for egg hatchability and a 66.7% inhibition rate for emergence. For the 3rd instar larvae, the feeding toxicities were over 90% for fenitrothion ($LC_{50}$ 336.6 ppm), esfenvalerate ($LC_{50}$ 8.6 ppm), ethofenprox ($LC_{50}$ 35.7 ppm), and emamectin benzoate ($LC_{50}$ 0.05 ppm). Furthermore, the contact toxicities were over 90% for esfenvalerate ($LC_{50}$ 0.87 ppm), ethofenprox ($LC_{50}$ 16.5 ppm), emamectin benzoate ($LC_{50}$ 0.53 ppm), and spinosad ($LC_{50}$ 2.48 ppm) at the recommended concentrations. Deltamethrin and spinosad yielded 100% mortality for adult P. operculella 48 h after treatment. The adult female fecundity was inhibited by deltamethrin, esfenvalerate, emamectin benzoate, spinosad and dinotefuran, which were significantly different from the control. The adult longevities (7.3-8.3 days) were reduced by approximately 1-2 days compared with the control (9.3 day). The emamectin benzoate maintained 100% insecticidal activity 14 days after treatment and ethofenprox maintained over 90% activity 7 days after treatment.