• Korean Journal of Agricultural Science
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• v.42 no.1
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• pp.7-13
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• 2015

Ninety genes randomly selected from tobacco whitefly (Bemisia tabaci) cDNA library was studied for selecting target gene in order to control of tobacco whitefly using TRV-VIGS vector (tobacco rattle virus-virus induced gene silencing vector) with RNAi. First of all, the occurrence of B. tabaci adult according to agro-infiltration of TRV was no significant difference. And that of TRV inserted tobacco whitefly cDNA showed a significant difference in each sample. P CV and N CV sample were more than 80% could be confirmed in 5 samples, for example, wh11, wh36, wh46, wh50 and wh71. Lastly, the occurrence of nymph and egg also showed a significant difference in each sample. That could be confirmed in 11 samples, for example, wh01, wh09, wh10, wh15, wh16, wh23, wh24, wh48, wh64 and wh66. In case of wh46, wh50 and wh71 sample could be confirmed that occurrence of B. tabaci adult was many, but occurrence of B. tabaci nymph and egg was a little. So sample showed a physioecological good effect to control of whitefly need to be investigated variation of gene expression in whitefly body using qRT-PCR through individual test.

• Korean journal of applied entomology
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• v.55 no.2
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• pp.109-117
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• 2016

We investigated the control of Bemisia tabaci adults in tomato greenhouses using the eggplant as a trap plant with 4 systemic chemicals. The control effect of dinotefuran SG 50% on tobacco whitefly adults was 80% mortality, the highest than that cyantraniliprole, pyridaben and clothianidin, 51.0%, 12.4% and 11.0% respectively when all chemicals with recommended doses were used. Dinotefuran was applied at various doses and was observed to be most effective above 200ppm (88.4%)t. The control effect of dinotefuran lasted for appromimately nine 9 days and the density of tobacco whitefly adults increased there after. In field tests, the densities of tobacco whitefly adults on tomato shoots were highest at points 0, 15 and 20 m from the eggplant traps and lowest at 5 and 10 m. When the density of tobacco whitefly was low and the eggplants with dinotefuran SG 50% were placed in the tomato greenhouse at 10 m intervals, the overall density of tobacco whitefly adults was lower. In addition, densities were higher at the side of the greenhouse than in the interior and further away from the eggplant. When the density of tobacco whitefly was high and the eggplants with dinotefuran were placed at 5 m intervals, the density of tobacco whitefly at each 5 m point decreased. Theses results confirm that the eggplant is an effective trap plant for attracting tobacco whitefly audlts and combined with dinotefuran SG 50% decreases the density of tobacco whitefly in tomato greenhouses.

• Korean Journal of Agricultural Science
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• v.42 no.2
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• pp.81-86
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• 2015

Three genes selected from cDNA library of tobacco whitefly, Bemisia tabaci, were checked whether these genes expressed in plant or not, and confirmed the change of gene expression using qRT-PCR in the tobacco whitefly. First of all, three genes were inserted in Tobacco rattle virus (TRV) RNA2 vector using Sac I and Xho I restriction enzymes, and conducted agro-infiltration in tobacco plants (Nicotiana benthamianana). And then, it was confirmed that TRV RNA2 vector and genes inserted in TRV RNA2 vector were expressed in plant. So, after feeding the tobacco whitefly the plants inoculated the genes and induced RNAi of the genes, we plan to confirm the RNAi in the whitefly and investigate the changes of gene expression through the qRT-PCR.

• Korean journal of applied entomology
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• v.53 no.4
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• pp.465-472
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• 2014

The tobacco whitefly, Bemisia tabaci, infest the Oriental melon and give significant economic damage along with its virus-vectoring activity. Various biotypes of B. tabaci have been well known and are classified depending on the severity of crop damage and insecticide susceptibility. In this study, B. tabaci adults were collected in the melon fields located in Poongchun-myeon, Andong, Korea and diagnosed on their biotypes using PCR molecular markers. From the all the 11 greenhouses, B. tabaci biotype Q was identified. In addition, biotype B adults were also found from the 4 greenhouses. These results report the first occurrence of B. tabaci at the Oriental melon farms in Gyeongbuk province with mixed infection by the two biotypes in the area.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.432-437
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• 2017

Yellow sticky traps have been commonly used for monitoring tobacco whitefly populations in open-fields, as well as in greenhouses. However, the attractiveness depends on various factors such as the reflected intensity (brightness) and hues of yellow color (wavelength) of the trap surface, which is often influenced by environmental conditions and may sometimes affect tobacco whitefly capture. Therefore, the use of light-emitting traps can be a significant complementary tool to strengthen the attractiveness and selectivity of these traps. This research was carried out in tomato greenhouses to evaluate the light-emitting trap as potential attractants for Bemisia tabaci adults. The results showed that B. tabaci adults on average preferred (p>0.05) traps in yellow lights (590 nm) ($168{\pm}7.6adults/trap$) compared to traps in white lights ($106{\pm}4.6adults/trap$) and traps without lights ($60{\pm}4.8adults/trap$). The yellow light trap(590 nm) showed the most attractive to B. tabaci adults, followed by a little lower attraction to the white light trap(450-625 nm), whereas the control (no light trap) was little attractive to B. tabaci adults. These results suggested that yellow and white light traps could have a promising use in greenhouses for the identification, monitoring, and pest control tools of tobacco whiteflies.

• Mycobiology
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• v.42 no.4
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• pp.346-352
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• 2014

Recently, the Q biotype of tobacco whitefly has been recognized as the most hazardous strain of Bemisia tabaci worldwide, because of its increased resistance to some insecticide groups. As an alternative control agent, we selected an Isaria javanica isolate as a candidate for the development of a mycopesticide against the Q biotype of sweet potato whitefly. To select optimal mass production media for solid-state fermentation, we compared the production yield and virulence of conidia between 2 substrates (barley and brown rice), and we also compared the effects of various additives on conidia production and virulence. Barley was a better substrate for conidia production, producing $3.43{\times}10^{10}$ conidia/g, compared with $3.05{\times}10^{10}$ conidia/g for brown rice. The addition of 2% $CaCO_3+2%$ $CaSO_4$ to barley significantly increased conidia production. Addition of yeast extract, casein, or gluten also improved conidia production on barley. Gluten addition (3% and 1.32%) to brown rice improved conidia production by 14 and 6 times, respectively, relative to brown rice without additives. Conidia cultivated on barley produced a mortality rate of 62% in the sweet potato whitefly after 4-day treatment, compared with 53% for conidia cultivated on brown rice. The amendment of solid substrate cultivation with additives changed the virulence of the conidia produced; the median lethal time ($LT_{50}$) was shorter for conidia produced on barley and brown rice with added yeast extract (1.32% and 3%, respectively), $KNO_3$ (0.6% and 1%), or gluten (1.32% and 3%) compared with conidia produced on substrates without additives.

• Korean journal of applied entomology
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• v.49 no.4
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• pp.417-422
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• 2010

Cultural characteristics Lecanicillium lecani Btab01 and its insecticidal activity against tobacco whitefly (Bemisia tabaci) were investigated. On potato dextrose agar, tryptic soy agar and SDA+Y media, mycelial growth of L. lecani Btab01 was best at $20{\sim}25^{\circ}C$ and suppressed above $28^{\circ}C$. Both solid culture and liquid culture of L. lecani Btab01 showed high insecticidal activity, 93.9 and 98.3% respectively, against nymph of tobacco whitefly, but there is no significant difference. When culture of L. lecani Btab01 was treated at the concentration of $10^5$, $10^6$, $10^7$ and $10^8$ cfu/ml, their insecticidal activity were 5.8%, 33.8%, 77.3% and 98.5% respectively, and $LT_{50}$ values were 16.1 days, 7.3 days, 5.1 days and 3.5 days respectively. When nymphs were treated by the cultures of L. lecani Btab01 and maintained under saturated condition for zero hour, 24 hours and 168 hours, their control activities were 0%, 20.3% and 100% respectively. Spore germination of L. lecani Btab01 was increased about two times by adding edible oil. When L. lecani Btab01 was treated to control nymph with 0.1% edible oil, it showed high control activity(98.6%) compared to single treatment of L. lecani Btab01 (79.9%).

• International Journal of Industrial Entomology and Biomaterials
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• v.18 no.2
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• pp.105-112
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• 2009

The greenhouse whitefly, Trialeurodes vaporariorum (Westwood) and the sweet potato whitefly, Bemisia tabaci (Gennadius) are serious insect pests that have a wide host range including cucumber, tomato, and pepper. In this study, we tested larvicidal efficacy of several on-the-market environment-friendly agricultural materials (EFAM) to select the effective products after the target pests were stabilized in indoor rearing condition. The developmental periods of two whiteflies are as follows: in the case of T. vaporariorum, egg duration is 9.6 days and nymph is 18.9 days, and in the case of B. tabaci, egg duration is 7.4 days and nymph is 15.2 days under $25^{\circ}C$ with relative humidity (RH) of $60{\pm}5%$ and a photoperiod of 16 L:8D. The total period of T. vaporariorum was 5 days longer than B. tabaci. Among 22 EFAMs six products showed more than 60% of insecticide efficacy against T. vaporariorum BTV B, BTV D, BTV G, BTV L, BTV M, and BTV S. On the other hand, seven EFAM products showed over 60% of insecticide efficacy against B. tabaci BTV D, BTV G, BTV K, BTV L, BTV M, BTV N, and BTV U. In the case of Spodptera litura previously, 16 EFAMs were tested against $2^{nd}$ instar S. litura, and six EFAMs were found to have more than 90% efficacy. Test of these six EFAMs against entire larval stages were performed in this study. Although some of these products showed still more than 90% of insecticidal efficacy against up to $3^{rd}$ instar larvae, the efficacy of these EFAMs sharply decreased as ages increase, resulting in less than 60% of efficacy of the products at most. This result indicates the difficulty to control S. litura with the on-the-market EFAMs alone under economic injury level. Collectively, it is required to find more EFAMs, and find alternative method, and combined way of controlling to control those insect pests tested in this study.

• Korean Journal of Agricultural Science
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• v.26 no.2
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• pp.13-18
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• 1999

External morphology characteristics of the greenhouse whitefly, Trialeurodes vaporarium were investigated by scanning electron microscopy. The antennae of the greenhouse whitefly was 6 segments. rod-shape, and 0.3mm length. On the 6th segment, there were many sensilla for searching host-plant as olfactory receptor. The mouthpart of the greenhouse whitefly was a piercing-sucing type, then its stylet was well developed for piercing plant leaf tissue. Claw of the foreleg was a 3-way hook shape including paranychium for attaching plant surface to pierce and lay egg.

• The Plant Pathology Journal
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• v.18 no.5
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• pp.231-236
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• 2002

Bemisia tabaci Genn. is an important pest worldwide because of its ability to cause damage by direct feeding and its role as a vector of some viruses including geminiviruses. The first report of Tobacco leaf curl virus (TLCV), a Geminiviruses, in Indonesia was in 1932 when the virus was found infecting tobacco plants in Central Java. The characteristic symptoms of TLCV included upward curling of the leaf edge, vein thickening, and sometimes the occurrence of enation on the underside of the leaves. Basic studies were carried out to elucidate the characteristics of TLCV transmission by its vector, B. tabaci. A single whitefly was able to transmit the virus and the efficiency of transmission was increased when the number of adult whiteflies was increased up to 20 per plant. Inoculation access period of 1 h could cause transmission up to 20% and the optimum inoculation access period was 12 h. Acquisition access period of 30 minutes resulted in 70% transmission while 1(10% transmission occurred with a 24-h acqui-sition access period. The virus was proven to be persistently but not transovarially transmitted. Discrete fragments of 1.6 kb were observed when polymerase chain reaction method was applied to detect the virus in viruliferous nymphs and individual adults of B. tabaci, while no bands were obtained from non-viruliferous nymphs and adults.