• Journal of Korean Society of Forest Science
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• v.90 no.4
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• pp.543-547
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• 2001

An fungus gnat, Bradysia agrestis in the family Sciaridae was collected from Pinus spp. seedlings. This pest is a newly recorded insect from P. thunbergii, P. rigida, P. rigitaeda, and P. densiflora seedling. Brief morphological characters, damage symptom, host plants associated with the B. agrestis were recored. Significant variation in damaged of Pinus spp. seedling was attributed to differences between pine species(P. thunbergii : 15.4-20.0%, P. rigida : 23.1-48.8%, and P. rigitaeda : 13.8-67.5%, respectively) and sowing times(May : P. densiflora, 0%; P. rigida, 0%, July : P. densiflora, 20.0%; P. rigida, 49.4%, respectively).

• Korean Journal of Environmental Agriculture
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• v.37 no.2
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• pp.125-134
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• 2018

BACKGROUND: Green peach aphid (Myzus persicae) is an insect pest that significantly affects crop production. A number of pesticides have been used for aphid control, but their concerns on insect resistance and food safety have required alternative methods for pest management. In an effort to find for an alternative approach to aphid control, we screened plants extracts and examined their potentiality as insecticidal bio-resources. METHODS AND RESULTS: Two hundred and ninety eight plant extracts were examined for insecticidal activity against the aphid, and the best candidate among them was chosen for further study. The extracts from Cinnamomum camphora was determined to be the best candidate exhibiting insecticidal activity more than 60% at a level of $1,000{\mu}g/mL$. GC/MS analyses detected camphor, borneol, 4-terpineol, ${\alpha}$-terpineol and caryophyllene oxide as major compositions from the extracts obtained by hydrodistillation. Caryophyllene oxide exhibited the highest insecticidal activity with a $LC_{50}$ value of $237{\mu}g/mL$. Camphor lowered significantly the $LC_{50}$ value of caryophyllene oxide and increased largely its concentration in aphid, suggesting that camphor played a role in enhancing the insecticidal activity of caryophyllene oxide. CONCLUSION: This study suggested that camphor and caryophyllene oxide may be used as an insecticidal bio-resource for insect control against green peach aphid.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.284-284
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• 2009

EFA production systems have through necessity resulted in the development of innovative practices for weed, pest and diseases control, for example, using ducks and snails for weed control in paddy fields. These practices began to be introduced in the early 1990's and the techniques have become more popular and have been adapted to suit regional conditions. In this study, the production practices, productivity and economic performances of organic and non-chemical rice farming adopting ducks and snails for weed control were compared. In the production practices, Korean organic and non-chemical farming seem to have several concerns in terms of sustainability. It comprises lack of resistant variety use and rotational cropping system as well as high dependency upon external inputs such as organic fertilizer and farming materials for pest control. The production level of organic farming is approximately similar level but 20% higher income than non-chemical farming, while, when it was compared with conventional farming organic farming showed 20% lower productivity but 20% higher income. Organic farming shows 15% to 18% higher profits than non-chemical farming as the snail-using organic farming tends to have higher income and lower input costs than duck-using organic farming. This may encourage more farmers to convert to organic production using these techniques than simply non-chemical farming in the future. This organic conversion could be more promoted by policy intervention. However, it may result in increased supply and therefore decreased prices for organic rice in the long term unless further market demand occurs. Balanced policy measures considering production as well as marketing and consumption are urgently required for the sustainable development of organic farming.

• Korean Journal of Agricultural Science
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• v.44 no.3
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• pp.348-358
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• 2017

The green peach aphid, Myzus persicae, is one of the most serious insect pest and a vector for a multitude of viral diseases to many crops, vegetables, ornamentals, and fruit trees in the world. A large number of aphids can reduce plant vigor and cause defoliation. Many insecticides have been developed and applied to control the green peach aphid. However, this aphid has displayed a remarkable ability to establish resistance to almost every insecticide. We treated 5 different insecticides registered for M. persicae on pepper leaves and investigated the effects of the insecticides by measuring the time it took to achieve 90% control of the aphids. Acetamiprid worked faster than any other insecticides while cyantraniliprole showed the slowest insecticidal effect. Pymetrozine, pyrifluquinazon, and spirotetramet provided 90% control within similar time. Iwol population's control value was higher than any other populations 24 hours after treatment. When five different unregistered insecticides for M. persicae were treated on pepper leaves, no insecticidal effect was found for gamma-cyhalothrin and novaluron and spinosad showed an insecticidal effect of up to 70% in Iwol population only. Although chlorfenapyr and dinotefuran were not registered for M. persicae, their insecticidal effects were found to be 90% or higher.

• International Journal of Industrial Entomology and Biomaterials
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• v.3 no.1
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• pp.97-99
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• 2001

Seven vegetables were planted in green houses to compare their yields and damages by insect pests based on three treatments, green music (GM), ultra sonic (US) and control. The vegetable yields of GM treatment were increased by an average of 17.81% than that of control for two years. There was a remarkable statistic difference in the yield between GM and respective controls such as radish, young radish, cucumber, spinach and Brassica oleracea var. acephala. There was no notable yield difference between US and controls for the semen vegetables within two years. The population densities of the insect pests in GM and US treatments were lower than controls. Only a few insect pests of some vegetables in GM and US treatments injured more seriously than in control.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.2
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• pp.157-159
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• 1991

The prevalence of warbles (Przhevalskiana silenus Brauer) and efficacy of ivomec against naturally occurring warble infestation in goats in Pothowar area of Pakistan was investigated. About 58.4% of the examined goats (total 301), were infedted by the warbles. The number of warbles per animal ranged from 1 to 23 (mean 5.1). Ivomec (ivermectin 1% w/v, Merck Sharp and Dhome, Netherlands) at the dose of 1 ml/50 kg of body weight proved excellent against this pest. The larvae of all the stages died inside the warbles after treatment and no skin perforations were observed in the treated animals. No side-effects of the drug were observed in the treated animals, except 2-3 minutes of bleating in a few animals at the time of injection.

• Korean journal of applied entomology
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• v.53 no.3
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• pp.321-321
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• 2014

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2017.11a
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• pp.59-60
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• 2017

• Korean journal of applied entomology
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• v.52 no.4
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• pp.379-386
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• 2013

Aphidius colemani and Orius laevigatus aree natural enemies of the control cotton aphid and western flower thrips, which are the major pests of cucumber plants. We evaluated the low toxicity of 47 fungicides against A. colemani and O. laevigatus, and we investigated the simultaneous effect of the natural enemies with fungicide of low toxicity on the pests. The toxicity of DBEDC, hexaconazole, pyraclostrobin, tribasic copper sulfate, triflumizole, chlorothalonil, flusilazole, folpet, carbendazim+diethofencarb, cymoxanil+fenamidone and trifloxystrobin to A. colemani mummies was more than 50% and to O. laevigatus was low toxic. Among the fungicides with low toxicity, azoxystrobin 20% WP was selected because it could be used simultaneously with A. colemani and O. laevigatus and as a fungicide to control powdery mildew and downy mildew. In 2011, the densities of western flower thrips and cotton aphid increased rapidly in early-May in Gongju and Cheonan, Chungnam Province. When azoxystrobin was used at an interval of 10 days in spring, A. colemani and O. laevigatus were released at an interval of 7 days at the early occurrence of the pests. The natural enemies decreased the densities of the pests; the maximum number of A. colemani mummies was 18 per lower leaf, and the maximum number of O. laevigatus was 0.5 per flower. Azoxystrobin did not influence the densities of A. colemani and O. laevigatus. The results show that the selected fungicides can be used with A. colemani and O. laevigatus for the intergrated pest management of cotton aphid and western flower thrips in cucumber polyvinyl house cultivation.

• Parasites, Hosts and Diseases
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• v.58 no.2
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• pp.153-159
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• 2020

The chigger mite Leptotrombidium sialkotense is one of the 6 main vectors of scrub typhus in China. Before present study, L. sialkotense was found in some parts of Hunan province, China with a narrow geographical distribution. During field investigation 2016-2017, we found L. sialkotense in Jingha, southern Yunnan, China. Of 15 small mammal host species, L. sialkotense were collected from 6 species of the hosts. Rattus brunneusculus was a dominant host of L. sialkotense, from which 98.3% of the mites were collected. The chigger mite showed a relatively high infestation prevalence (P_M =11.7%) and mean abundance (MA=0.5) in comparison with the rest 5 host species. These results reveal a certain host specificity of L. sialkotense to a rat R. brunneusculus. The mite L. sialkotense showed an aggregated distribution on the host (P<0.05). A positive correlation observed between L. sialkotense and the body length of hosts. There was a positive interspecific association between L. sialkotense and 2 other dominant vectors, L. deliense and L. scutellare.