• Korean Journal of Medicinal Crop Science
• /
• v.8 no.1
• /
• pp.74-78
• /
• 2000

This study was carried out to select the effective insecticides for control of Ostrinia furnacalis(Guenee) in Yonchon, northern part of Kyunggi province, where is main producing region of adlay in Korea. The Asian corn borer in adlay field had three generations a year. The first stage of adult activity was higher from late May to middle June, the second from late July to early August and the third late September. Based on difference in control value, the relative ranks of some insecticides were lambda cyhalothrin EC > cartap hydrochloride GR > carbaryl EC. In control value by different application timing of Lambda cyhalothrin EC, yields were significantly different, that is, twice applications on second generation showed the control value of $90.6%{\sim}93.5%$. Unhulled grain yield on Lambda cyhalothrin EC treated plot on second generation was higher than that in untreatred plot by 82%.

• Korean Journal of Organic Agriculture
• /
• v.26 no.2
• /
• pp.245-257
• /
• 2018

The efficacy of different control techniques against the large black chafer, Holotrichia parallela Motschulsky (Coleoptera: Scarabaeidae), in organic pear (Pyrus pyrifolia) orchards was evaluated. In this study, field trials were conducted in three locations in Korea-Naju, Hampyeong, and Boseong-to evaluate different techniques to suppress these beetles. Pheromone traps, bio-insecticides (Hongmengye and Melchungdaejang), and a combination of the two were applied as treatments. In Naju, Hampyeong, and Boseong, the highest number of adult H. parallela were caught in the control plots (n=45, n=39, and n=20, respectively), while the fewest were caught in the pheromone plus bio-insecticide plot (n=19) in Naju and in the combined treatment plot in Hampyeong (n=10). In Naju, the greatest leaf damage was observed in the control (66%), and in all locations (Naju, Boseong, and Hampyeong), the least damage occurred in the combined treatment plots (42%, 36%, and 24%, respectively). Regarding the tree canopy, the greatest leaf damage was observed in the upper canopy, and less damage was observed in the lower canopy. These results demonstrate that the combination of sex pheromone traps and bio-insecticides can be used to manage H. parallela in organic pear orchards.

• The Korean Journal of Pesticide Science
• /
• v.12 no.4
• /
• pp.397-402
• /
• 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
• /
• v.18 no.1
• /
• pp.41-47
• /
• 2014

This study was performed to evaluate the exposure level of organophosphorus and pyrethroid pesticide to floriculture workers and florists. The urinary dialkylphosphates, metabolites of organophosphorus insecticides, including dimethylphosphate (DMP), diethylphosphate (DEP), dimethylthiophosphate (DMTP), diethylthiophosphate(DETP) and pyrethroids of metabolites, cis/trans DCCA, DBCA, and 3-PBA were analysed to evaluate the exposure of organophosphorus and pyrethroid pesticide to floriculture workers and florists. The concentration of DMP is highest in floriculture workers. but the concentration of DETP is highest in retail florist. The concentration of 3-PBA is highest in floriculture workers. The amount of organophosphorus and pyrethroid pesticide expusure is highest in flower workers, wholesale florist and retail florists are followed. The management for reducing pesticide exposure to floriculture workers and wholesale florist is required.

• The Korean Journal of Pesticide Science
• /
• v.4 no.2
• /
• pp.63-68
• /
• 2000

This study was conducted to investigate insecticidal mechanisms of the new insecticides DBI-1015 and DBI-3204 with label compounds of chitin precursors, [$^{14}C$] N-acetylglucosamine and [$^{14}C$] UDP-N-acetylglucosamine in Spodoptera litura. The concentrations of the insecticides for incorporation of chitin precursors into chitin were founded to be functional relationship. The result of in vivo test, $I_{50}$ (ppm) of the DBI-1015, DBI-3024 and diflubenzuron to [$^{14}C$] N-acetylglucosamine were 0.57, 0.89 and 0.26 ppm respectively, and to [$^{14}C$] UDP-N-acetylglucosaminen were 0.99, 0.53 and 0.45 ppm respectively. in vitro test of DBI-1015, DBI-3024 and diflubenzuron by integument fragments, the incorporation rate in the cuticle were low, however, $40{\sim}60%$ inhibitions were observed at $2{\mu}M$ when compared to the untreated control.

• The Korean Journal of Pesticide Science
• /
• v.20 no.2
• /
• pp.159-164
• /
• 2016

The winter cherry bug (Acanthocoris sordidus Thunberg, Coreidae, Hemiptera) is a insect pest that have a piercing sucking type mouthpart, and it is injured to solanaceous plants including pepper plant. For the control of the winter cherry bug, 20 organic synthetic insecticides and 7 environmental friendly agricultural materials (EFAMs) were selected with single formulation. Fenitrothion, fenthion and phenthoate were significantly higher mortality to adults and 3rd instar nymphs of winter cherry bug as over 95 and 100 % after 72 hours with treatment. Otherwise, in case of EFAMs, there is no significantly higher effective materials to adults and 3rd instar nymphs of winter cherry bug. Eighty percentage of Sophora flavescens was showed only around 50% mortality with the high variation after 72 hours with treatment against adult of the winter cherry bug.

• Korean journal of applied entomology
• /
• v.43 no.3 s.136
• /
• pp.257-262
• /
• 2004

Toxicities of 51 pesticides (25 insecticides, 11, acaricides, 11 fungicides and 4 adjuvants) commonly used to control greenhouse insect, mite, and disease pests were evaluated to minute pirate bug, Orius strigicollis nymphs and adults at the recommended concentration. Among 25 insecticides tested, fipronil, lufenuron, acetamiprid+fipronil, $\alpha$-cypermethrin+flufenoxuron and buprofezin + amitraz showed low toxicity to O. strigicollis. Among acaricides, acequinocyl, bifenazate, chlorfenapyr, etoxazole, fenpyroximate, flufenoxuron, milbemectin, spirodiclofen and tebufenpyrad showed low toxicity to O. strigicollis. All fungicides and adjuvants tested were very low toxicity. It may be suggested from these results that five insecticides, nine acaricides, eleven fungicides and four adjuvants could be incorporated into the integrated thrips management system with O. strigicollis in greenhouses.

• Korean journal of applied entomology
• /
• v.43 no.3 s.136
• /
• pp.241-247
• /
• 2004

Susceptibility of Blattella germanica male adults to 61 commercial insecticides was evaluated by diet dipping method. Among them three insecticides of dichlorvos, fenitrothion, and fipronil showed over $90\%$ mortality. The insect was more susceptible to dichlorvos and fenitrothion in filter paper contact method than in diet dipping one, but fipronil was vice versa. Toxicities of the three chemicals were evaluated by application parts of the such as head, thorax, abdomen, and legs. Dichlorvos and fenitrothion were more toxic when applied to head, and flpronil was thorax. $LT_{50}$ values by diet dipping method showed that fenitrothion and fipronil acted more rapidly than boric acid and hydramethylnon. The values of the former two were 1.05 and 0.98 days, and those of the latter two were 3.92 and 2.26 days, respectively.

• Korean journal of applied entomology
• /
• v.31 no.3
• /
• pp.314-327
• /
• 1992

Insecticide resistance is a serious is a serious threat to IPM, resulting in various adverse effects not to mention the loss of yield in agriculture. One approach to counter the problem is the disruption of resistance mechanisms. This can be achieved by (1) compounds which show a negative correlation with resistance at the site of action, (2) specific metabolic inhibitors which serve as synergists, or (3) a certain combination of two insecticides producing a joint action. This approach, however, requires certain precautions for the side effects may cause an increase in toxicity to mammals. Owing to the recent advances in theoretical studies on resistance management employing computer simulation and mathematical models, a few principles to reduce the risk of development of resistance have been clarified. They are helpful in designing operational strategies with regard to, for instance, insecticide doses to be applied, mode of application, and choice and nature of the insecticide(s) to be used. For restoration of insecticide susceptibility of a resistant population, reintroduction of susceptible individuals to the resistant population is feasible when certain conditions are met. Natural enemies which developed resistance to insecticides can be an important component of IPM as has been shown in the pest management in apple orchards. After all, the implementation of a successful resistance management program depends upon cooperation between different sigments of the agricutural community. Although resistance is a preadaptive phenomenon, in some cases spontaneous loss of resistance does occur without contamination by susceptible individuals. The instability of resistance in these insects implies the possible existence of a switch machanism controlling the expression of resistance gene(s). Elucidation of such a mechanism may eventually provide us with a new technical approach with which we can combat the problem of insecticide resistance.

• Korean journal of applied entomology
• /
• v.9 no.2
• /
• pp.75-80
• /
• 1970

1. Retention of fungicides and efect of the mixing of spreaders and insecticides with fungicides in control of apple bitter rot were evaluated by 'the assay of inhibition zones with apple exocarp disks:' 2. The effectiveness of chemicals was reduced gradually as the time after treatment increased. Of all the chemicals tested, Difolatan retained approximately 60 percent of the original activity even after IS days. Difolatan had the highest followed by Tuzet, Phaltan, Bordeaux mixture, and Delan, in that order. 3. The fungicidal acivity of Tuzet decreased with increasing application of simulated rain. The wash-offf of Tuzet was reduced by adding spreaders. Dry skim milk and soybean extract were better than commercial chemicals such as Lino No. 1,2 and Tween 20. 4. The mixing of insecticides such as EPN, Folithion, Parathion and Lebaycid with Phaltan resulted in no significant differences in fungicidal effect even after 12 days of storage at room temperature.