• Korean journal of applied entomology
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• v.48 no.2
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• pp.179-188
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• 2009

Nymphal development of the B and Q biotypes of Bemisia tabaci was normal on all seven tomato varieties tested. However, their nymphal development was different on red pepper varieties. B biotype was not normally developed on nine red pepper varieties tested. On the contrary, Q biotype was normally developed, but its adult emergence rate was very low in Nokkwang variety than in other eight varieties. The EPG analysis of the feeding behavior of Bemisia tabaci showed that B and Q biotypes had different duration of phloem phases on red pepper. Q biotype showed longer phloem phases than B biotype. On Nokkwang variety, Q biotype had short phloem phases and did not prefer to feed on Nokkwang variety. Interestingly, Q biotype was found to have long duration of phloem phases on eight red pepper varieties, but B biotype did not prefer to feed on red pepper varieties. However, both biotypes did not show any difference in feeding time on tomato varieties.

• Korean journal of applied entomology
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• v.44 no.3 s.140
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• pp.169-175
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• 2005

The occurrence of tobacco whiteflies, Bemisia tabaci, in greenhouses was monitored in Korea in 2005. Bemisia tabaci occurred in the rose, sweet pepper, tomato, and cucumber greenhouses of Chungbuk, Chungnam, Gyongnam, and Jeonnam Provinces, but not in Jeonbuk and Gyongbuk Provinces. The biotypes and genetic differentiation of the whiteflies collected in each regions were analyzed by mitochondrial 16S DNA sequences. The 16S DNA sequences of Jincheon (Chungbuk Province) samples were similar to DNA data reported from Japan and Israel which were known as the B biotype. However, the DNA sequences of the Buyeo (Chungnam), Geoje (Gyongnam) and Boseong (Jeonnam) collections, which were 100% homologous showed over 99% similarity to the DNA of Q biotype from Spain and Egyrt. Here we report the first founding of the Q biotype in Korea. It is assumed that, unlike the B biotype reported from Jincheon since 1998, the Q biotype might have been introduced recently from the certain foreign region/country to the greenhouses in those provinces.

• The Korean Journal of Pesticide Science
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• v.7 no.3
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• pp.207-215
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• 2003

This study was carried out to evaluate toxicities of 3 registered insecticides to greenhouse whitefly(GWF), Trialeurodes vaporariorum and sweetpotato whitefly(SWF), Bemisia tabaci, B-biotype. Insecticide activities were evaluated by testing systemic action, residual effect in the laboratory, and control efficacy in the greenhouse. All experiments were tested at the recommended concentration(RC), half and a quarter concentrations of RC of each insecticides. Acetamiprid showed 45%, 42% ovicidal effect to greenhouse whitefly and sweetpotato whitefly at 40 ppm, respectively. Acetamiprid showed more than 97% larvicidal activities on the 3rd instars larvae of GWF and SWF at the recommended and its half concentrations. On the adults of the two whitefly species, acetamiprid and acetamiprid+ethofenprox showed more than 92% mortality even at half of recommended concentrations. Acetamiprid and acetamiprid+ethofenprox showed both residual effect and systemic activity. In the control efficacy test on GWF and SWF, 90% control values were obtained at the 3th day after treatments of acetamiprid and acetamiprid + ethofenprox by application with recommended concentration. These results indicate that acetamiprid and acetamiprid+ethofenprox can be used in the control of the two whitefly species in field.

• The Korean Journal of Pesticide Science
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• v.14 no.4
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• pp.433-439
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• 2010

This study was performed to investigate repellent effect of plant essential oils against Bemisia tabaci adult. Among the 20 tested oils, wild mint oil repelled B. tabaci adult significantly (>90%) at a dose of $5{\mu}{\ell}$, but the other oils did not. In dose responses (2, 1, 0.5, $0.1{\mu}{\ell}$) to B. tabaci adult, wild mint oil showed repellent response (77.8~65.7%) significantly with dose-dependent manner. Wild mint oil analyzed by GC/MS revealed that the major components of wild mint oil were menthol (56.5%), menthone (29.0%) and menthyl acetate (14.5%), and the active components responsible for the effective repellency proved to be menthol (77.8%) and menthone (75.8%) when treated the proportion found in original oil. However, menthyl acetate did not show significant repellency. Combined constituents of wild mint oil were showed synergistic effect.

• Korean Journal of Environmental Agriculture
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• v.35 no.1
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• pp.46-54
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• 2016

BACKGROUND: The tobacco whitefly(Bemisia tabaci Gennadius) and western flower thrips(Frankliniella occidentalis Pergande) seriously damaged to several greenhouse crops and transmitted plant viruses such as the Tomato Yellow Leaf Curl Virus(TYLCV) and Tomato Spotted Wilt Virus(TSWV). Objective of this study was to elucidate exclusion effects of insect screen nets by various hole sizes and colors for control of the two insect pests in controlled environments such as a closed plant production system.METHODS AND RESULTS: The exclusion effects to various hole sizes of three other colors with 30 individuals of two insect pests was evaluated. B. tabaci was not showed not difference to different colors and sizes. F. occidentalis showed that 0.2 mm black screen was the most effective exclusion than other colors of 0.6 and 0.8 mm.CONCLUSION: The two insects were different reponses to various hole sizes of white and other color screen nets. It was proved that the 0.4 mm white screen net used in this experimental condition was suitable for exclusion of B. tabaci and 0.2 mm black forF. occidentalis.

• Korean journal of applied entomology
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• v.54 no.2
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• pp.91-97
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• 2015

The sweetpotato whitefly, Bemisia tabaci, is the major insect pest that transmitted over 100 plant viruses including tomato yellow leaf curl virus (TYLCV) of tomato plant as virus vector in the world. In this study, cDNA library of whitefly was constructed using Gateway system for selecting target gene in order to control of B. tabaci using virus-induced gene silencing (VIGS) vector with RNAi. First of all, when using oligo d(T) rimer, the calculated titer of cDNA library was confirmed with $1.4{\times}10^4$ clones and average insert sizes was confirmed with 1 kb. However, insert size was very big for construction of cDNA. Otherwise, when using attB-N25 random primer and sonication for 6 sec, the calculated titer of cDNA library was confirmed with $1.04{\times}10^5$ clones. But mostly insert band wasn't identified on the electrophoresis, because it seemed that insert size is too small (${\leq}100bp$), also the size of identified insert was somewhat big. Finally, when using oligo d(T) primer and sonication for 1 sec, cDNA insert of whitefly was appropriated for VIGS with 300-600 bp. However, cDNA sequence included a poly A and titer was very low to $5.2{\times}10^2$ clones. It was supposed that heat shock transformation was used instead of electro-transformation. It is considered that when constructing cDNA library for using VIGS vector, (1) random primer should be used for First strand cDNA synthesis in order to remove poly A and (2) sonication for 1 sec should be performed in order to get appropriated insert size and (3) electro-transformation should be performed in order to improve transformation efficiency.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2001.05a
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• pp.71-71
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• 2001

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2005.05a
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• pp.192-192
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• 2005

• Korean Journal of Environmental Biology
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• v.38 no.4
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• pp.616-624
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• 2020

International trade is one of the primary ways that non-native species spread worldwide. Korea and China are geographically close and have a large mutual trade volume. To investigate the population movement of the invasive whitefly(Bemisia tabaci Gennadius) between the two countries, we compared the biotype distribution, insecticidal response, and the TYLCV(tomato yellow leaf curl virus) viruliferous rate of local populations collected in 2019. Based on the mitochondrial DNA COI sequences of B. tabaci, only the Q biotype was found in all populations in Korea, whereas the B biotype (14.3%) and Q biotype (85.7%) were found in China. In the haplotype composition of the B. tabaci Q biotype, only the Q1 group[Q1H1(79.8%) and Q1H2(20.2%)] was observed in China, but the Q1 group [Q1H1(1.7%) and Q1H2(97.5%)] and the Q2 group(only one individual) were found in Korea. The Korean populations showed high mortality(more than 80%) from 15 commercial insecticides, but the Chinese populations showed significantly low mortality from eight insecticides. No TYLCV infections were observed in the Korean populations while the average TYLCV viruliferous rate was 21.4% in the Chinese populations. Taken together, the results suggest that the population structures of B. tabaci in the two countries are different and may have different immigration histories.

• Korean journal of applied entomology
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• v.63 no.1
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• pp.75-76
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• 2024

The ovicidal effect of plant extract mixture (5%cinnamon extract + 10% citronella oil + 30% citrus oil + 10% derris extract + 20% neem extract + 25% penetrating surfactant) against several major insect pests was tested using the spraying method. In the case of stink bugs, eggs tended to die during hatching. When treated with a plant extract mixture (500-times solution), mortality for Halyomorpha halys, Riptortus clavatus, Eurydema dominulus, Trialeurodes vaprarorium, Bemisia tabaci, Spodoptera exigua, and Agrotis ipsilon reached as high as 100%. Therefore, it is believed that industrialization will be feasible in the future.