경기지역에서 담배가루이의 발생 및 약제반응을 조사하였다. 담배가루이는 13개 시군에서 발생되었으며, 유전자(16S rRNA, MtCOI) 분석결과, 고양시 일부지역은 biotype B와 Q가 혼재되었으나, 그 밖의 지역에서 2005부터 국내 발생이 보고되었던 biotype Q로 나타났다. 채집곤충 및 기주식물의 total DNA에 대해 PCR을 통한 염기서열 분석과 southern hybridization 분석 결과 모든 지역에서 Tomato Yellow Leaf Curl Virus(TYLCV)는 검출되지 않았다. 5개 지역에서 채집한 6 개체군의 담배가루이를 실내사육하면서 유묘검정법으로 성충에 대한 살충제 감수성을 검정한 결과, 지역별로 다소 차이는 있었지만 네오니코티노이드계 약제의 경우 biotype B에게 높은 살충활성을 나타낸 반면 biotype Q에게는 상대적으로 낮은 살충활성을 나타내었다.

 ,  , Aleurolobus marlatti (Quaintance), Massilieurodes formosensis (Takahashi), and Pealius rhododendri Takahashi were found for the first time in Korea. This study provides a brief summary and photographs of the major characters of these species and an updated identification key to the whitefly species known to occur in Korea.

Population dynamics of greenhouse whitefly, Trialeurodes vaporariorum, were modeled and simulated to compare the temperature effects of air and tomato leaf inside greenhouse using DYMEX model simulator. The population phenology model of T. vaporariorum was developed and simulated. Leaf temperature on reversed side of cherry tomato leafs was monitored according to three tomato plant positions (top, >1.6m above the ground level; middle, 0.9 - 1.2m; bottom, 0.3 - 0.5m) using an infrared temperature gun. Air temperature was monitored at same three positions using a temperature logger. The leaf temperatures from three plant positions were described as a function of the air temperatures. The number of T. vaporariorum immatures was counted by visual inspection in three positions to verify the performance of DYMEX simulation. A significant positive correlation between the observed and the predicted numbers of immature and adults was found when the leaf temperatures were incorporated into DYMEX simulation, but no significant correlation was observed with air temperatures. This study demonstrated that the population dynamics of T. vaporariorum was affected greatly by the leaf temperatures, rather than air temperatures in cherry tomato greenhouses. This work was supported by Development of field-oriented model for forecasting outbreak of diseases or insect pests based on GIS and IT Program (R1003852) from Rural Development Administration, Republic of Korea.

Recently, the Q biotype of tobacco whitefly has been recognized as the most hazardous strain of worldwide because of increased resistance to some insecticide groups requiring alternative strategies for its control. We studied the susceptibility of this biotype of B. tabaci to 21 isolates of Beauveria bassiana, 3 isolates of Isaria spp., 1 isolate of P. cateni，3 isolates of Lecanicillium lecanii, 1 isolate of L. attenuatum and 1 isolate of Aschersonia aleyrodes. These isolates were evaluated on pruned egg plant seedlings, at a concentration of 108conidia/ml (deposited at 6000±586 conidia mm-2). The mortality based on mycosis varied from 18 to 97% after 6 days. An Isaria sp. isolate, two B. bassiana isolates and a L. lecanii isolate were found the most effective. Furthermore, five isolates were chosen for concentration-mortality response assays and compared to B. bassiana GHA as a standard. The numbers of nymphs infected by fungi were correlated with the spore concentration. A L. lecanii isolate and Isaria sp. had the short LT50 at 6000±586 conidia mm-2. Mortality reduced and LT50s were longer as the concentration of conidia was reduced. The LD50 values were differed in isolates from 87 to 269 conidia mm-2. These results indicated that the Q biotype of sweetpotato whitefly was susceptible to the five isolates of entomopathogenic fungi and these isolates have potential to be developed as a microbial pesticide for whitefly control.

Effectiveness of Encarsia formosa (Hymenoptera: Aphelinidae) to control Trialeurodes vaporariorum (Hemiptera: Aleyrodidae) was investigated in the commercial tomato greenhouse from January to June, 2010. Densities of T. vaporariorum were monitored using the yellow sticky trap for adult, and a lupe (x10) for 4th instar nymph and pupa at 1 week interval. Tomato seedlings were transplanted in mid-January and the nymph and adult of T. vaporariorum were first discovered in February 4th. E. formosa was applied as a mummy card at a recommended density (3 parasitoids per 1m2) at 2 weeks interval for 8 times. Mummy cards were collected 2 weeks later and the emergence and survival ratio of E. formosa were examined. Density of adult T. vaporariorum was significantly lower in the treatment plot (F=42.48, p=0.0001). The control efficiency ranged from 57.3% to 88.5%. The nymphal density was also significantly lower in the treatment plot (F=8.85, p=0.0053). The control efficiency was 84% on 25th March, 75% on 18th May and 95% on 25th May. Maximum 50% parasitism by E. formosa occurred in the treatment plot. The emergence and survival rates of E. formosa on mummy cardboards that were released in the greenhouse during February to March were only 53% and 41%, respectively. These rates increased to >70% as the temperature rises.

two different sizes of yellow sticky traps (small trap: 9.6×8.0cm; large trap: 9.6×16cm) for sampling greenhouse whitefly (GHWF), Trialeurodes vaporariorum (Westwood), adults in four commercial cherry tomato greenhouses. The patch size of GHWF immatures between plants was also estimated using visual counts. Two variogram models were fitted to the empirical variograms developed from the data collected by each sampling method. All the variograms reached the sill indicating the presence of spatial dependence among the spatial data obtained by the two sampling methods. For GHWF adults on sticky traps the range of variogram (a measure of attractive distance) was not different between the two trap sizes. This result indicated that the attractive distances of the two different yellow sticky traps were very similar. The ranges of the variograms for the visual count of immatures on plants were always less than those for adults, indicating that the attractive distance of the traps for GHWF adults extends beyond the patch size for immatures on cherry tomato plants. These data have implications for developing sampling plans for the management of GHWF in tomato greenhouses.

The green peach aphid(Myzus persicae) and sweet-potato whitefly(Bemisia tabaci) biotype Q are serious pests in hot pepper and cucumber. To optimize the formulation type of Clothianidin 1.8% granule, coated and extruded granule formulation types were tested against green peach aphid in hot pepper and sweetpotato whitefly in cucumber. Clothianidin 1.8% granules were incorporated in soil before transplant of hot pepper and cucumber. At recommend dose(540g ai/ha), the efficacy of Clothianidin 1.8% coated and extruded granules were 83.3% and 94.4% and continued until 50 days and 70 days against green peach aphid, respectively. Against sweet-potato whitefly, the efficacy of Clothianidin 1.8% coated and extruded granules were 65.7% and 96.3% at 32 days in cucumber, respectively. Clothianidin 1.8% extruded granule was safe on crops (hot pepper, cucumber, melon, cabbage etc.) at 540g ai/ha (recommend dose) and 1080g ai/ha. The results suggested that Clothianidin 1.8% extruded granule is promising as a best insecticide against green peach aphid and sweet-potato whitefly, because of the high efficacy and low phytotoxicity.

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 20~25℃ and suppressed above 28℃. 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 10⁵, 10⁶, 10⁷ and 10⁸ cfu/ml, their insecticidal activity were 5.8%, 33.8%, 77.3% and 98.5% respectively, and LT<SUB>50</SUB> 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%).

The oral toxicities of symbiotic bacteria Photorhabdus temperata ssp temperata (Ptt), mutually associated with entomopathogenic nematode Heterorhabditis megidis, and P. luminescens ssp. laumondii (TT01) with H. bacteriophora, were demonstrated to adults of the sweetpotato whitefly Bemisia tabaci. Sucrose solution (25%) containing bacteria-free supernatant of culture media of symbiotic bacteria was ingested into adult whiteflies within the glass tube. Whitefly mortalities were shown similar patterns against two bacterial media. Mortalities were significantly increased to 60-64% at 36 hours and almost 100% at 60 hours after treatments. In addition, We demonstrated the effect of oral ingestion of symbiont culture media on the gene expression of B. tabaci. Several genes fluctuated those expression levels. Our results suggest that oral ingestion of symbiont culture media of entomopathogenic nematodes significantly changed metabolic rates and highly lethal to whiteflies. The use of symbiotic bacteria of entomopathogenic nematodes provides a great potential as an alternative genetic resource of Bacillus thuringiensis, a major resource of microbial insecticide.

Insect pest may move to near area to forage the food by adverse changes of their environments. Understanding these behaviors of searching the host will be helpful for further control. This study was performed to investigate the host preference and distribution of B. tabaci in a host plant when they needs. Once entered an area including hosts, B. tabaci will select a host rather than non-host and stayed for living. Dispersal within a niche (in a whole plant), B. tabaci was observed in lower part in tobacco and middle in tomato when seedlings, but they dispersed throughout the whole fully grown tomato plants with irregular inclined to the under, outer stretched leaves. Bemisia tabaci was also caught massively in yellow sticky traps in height of 30 cm above soil, and 30 cm above a plant. There was no attraction effect by flower model traps and fly catcher. When introduced with different densities (0, 10, 50, 100, 200, and 400) in square cages, the B. tabaci do damaged at the densities of 200 with mild and 400 with severe symptom on plants in two weeks and four weeks after inoculation.

Sweet potato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is a serious pest of many economically important crops. The insect has developed resistance to chemical insecticides. Therefore, the development of microbial agent such as entomopathogenic fungi, Lecanicillium lecanii is necessary. Spores of L. lecanii Btab01 was collected after cultivation on solid PDA and liquid RB (rice bran amended with 2% molasses) media. The bioassay was carried out with B. taabci nymphs for 7 days at 25℃ and 60% relative humidity. Further, mortality was corrected with appropriate controls. The results revealed that spores obtained from RB medium caused high mortality (98.31%) compared to PDA medium (93.94%). Spore concentrations 105, 106, 107, and 108 colony forming units (c. f. u) ml-1 caused 5.81, 33.80, 77.27, and 98.54% mortality, respectively. The mortality (100%) was observed for 4 days when L. lecanii spores was mixed with 0.1 - 0.3% soybean oil. Hence, it is concluded from this study, L. lecanii Btab01 cultivated on RB medium can be recommended to control the nymphs of B. tabaci. Spore suspension can be expected to high efficacy when soybean oil was blended.

Dongbu HiTek had a focal group depth interview with pesticide sales dealers and farmers in 2007. With results, dealers assessed a white fly as a most difficult pest in up-land crop cultivation, and answered the increase and change of pests and pathogen from climate change as a most concerned event. Farmers pointed that important jobs in vegetable cultivation were the control of pest and pathogen (34%) and the prevention of pest and pathogen (24%). And difficult works was the control of pest and pathogen (24%), and the climate change (18%). When choosing the insecticide, the long lasting activity (44%) and the completeness of control (34%) were the important factors. Among customers’ claims related with white fly, claims on insufficient efficacy was dominant and occupied 86% in spite of efforts of producers, and it reflected that commercial agrochemicals did not meet the expectation level of the farmers. Common agrochemicals for the control of white fly are Neo-Nicotinoids in Korea today and CGAR of it is about 13% average increased per year from 2003. As Bio Type Q showed higher resistant level to the Neo Nicotinoids than other Bio type (Nauen et al. 2002), Bio Type Q would spread easily and counter-plan is needed.. Market size of agrochemical for white fly is assumed to be about 9.6 million US dollars. The market size is smaller than that of aphids or lepidopterous pests, but the market would increase because of suffering and failure in control due to resistance and resurgence problems. As the increase of vegetable consuming, host crop for the white fly is also increasing. As green house cultivation area of host vegetable increases, natural enemies to foreign invading pest like sweet potato white fly are limited. Also it is important that that management of pest and pathogen in green house environment. It is essential to build pest management model and to develop and commercialize agrochemicals according to the critical customer (farmer) requirement.

The sweet potato whitefly Bemisia tabasi is one of the most important pests of various horticultural crops. In addition, B. tabaci is a vector of many plant-pathogenic viruses and cause a serious secondary damage to crop plants. Association of plant-pathogenic virus with vector insects is known to be effective on the transmission capacity, fecundity, longevity of vectors including whiteflies. However, the interactive mechanisms between virus and vector insects are still poorly understood. Recently, a serious damage caused by virus disease together with B. tabasi emergence was identified at tomato glasshouse in Tongyoung. We detected the signals of Tomato Yellow Leaf Curl Virus (TYLCV) in tomato leaves and vector whiteflies using PCR amplification and confirmed its presence by those sequence comparison. To determine the effects of TYLCV acquisition on physiological status of vector whiteflies, transcript levels of genes that associated with metamorphosis, metabolism, stress and immune processes were compared between TYLCVinfected whiteflies and non-infected ones. Generally, the transcript levels of virus-infected whiteflies were lower than those of non-infected ones. In addition, the associations of endosymbiont levels within whiteflies were discussed in aspect of the acquisition and transmission of TYLCV.

The whitefly Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) is one of the most important agricultural pests in Japan, that causes retard of plant growth and sooty moulds through excreted honeydew by direct sucking of pholoem sap, and additionally transmits several kinds of plant virus. B. tabaci consists of more than 20 biotypes which possess different ecological or physiological characters but cannot be distinguished from others morphologically. In Japan, exotic B and Q biotypes are the common pests of vegetables, flowers and ornamental plants. B biotype, the silver-leaf whitefly, was first recorded in Aichi Prefecture, Tokai region, in 1989 and expanded its distribution to almost all part of Japan, except for the northern area, within several years. Q biotype was recently found in Hiroshima Prefecture, Chugoku region, in 2004 and is still expanding the distribution in our country. Indigenous B. tabaci biotypes also exist in the southwestern part of Japan: JpL biotype was recorded in Honshu, Shikoku, Kyushu Islands and Nauru biotype was found in Amami and Ryukyu Islands. Although the host plants of these indigenous biotypes include some agricultural crops, these insects are not important as agricultural pests. The most serious problem in vegetable cultivation caused by B. tabaci is an intensive epidemic of the tomato yellow leaf curl disease (TYLCD) which leads to a large yield loss of tomato production in green houses. TYLCD distributes worldwide and it was found in Aich and Sizuoka Prefectures, Tokai region, and Nagasaki Prefecture, Kyushu region, simultaneously in 1996. The distribution of TYLCD expanded mainly in the western part of Japan for several years after its first finding, but recently TYLCD started to occur also in the eastern part of Japan, Kanto and Tohoku regions. Tomato yellow leaf curl virus (TYLCV), a pathogen of TYLCD, is transmitted by B or Q biotype of B. tabaci in a persistent manner. Although an effective control of B. tabaci is essential for decreasing of TYLCD outbreaks in tomato green houses, it is quite difficult to control these whiteflies only by the spraying of chemically synthesized insecticides due to their insecticide resistance. Especially, Q biotype shows a high level of resistance to pyriproxyfen and neonicotinoid insecticides. To avoid the development of insecticide resistance in B. tabaci, we are trying to combine some different control methods, for example, use of a fine mesh screen to prevent the invasion of vector insects, use of the physical-coating or microbial insecticides with the chemically synthesized insecticides to prevent the reproduction of vector insects, closing and steaming of a green house at the end of tomato cultivation to kill vector insects and prevent their escape from there, as an integrated pest management (IPM) system for B. tabaci and TYLCD control. We are also breeding TYLCV resistant varieties of tomato and considering how to use these varieties effectively.

Tobacco whitefly-Bemisia tabaci is considered one of the most important pests in tropical and subtropical agriculture, as well as in production systems in glasshouses in temperate zones. Principle research on the identity of B. tabaci began with the recognition of more than one biotype differing in life history parameters, host plant associations, plant-related damage and insecticide resistance. Our laboratory strains of B. tabaci were identified and classified as biotype B and Q, through mtCOI PCR. Also, they were tested for their host plant preference and reaction to different insecticide. Biotype Q prefers to feed on red pepper and tomato, was less susceptible to tested insecticides, for instance acetamipirid, spinosad and thiamethoxam, than the biotype B (feed on tomato alone). There has been a report on the presence of gut bacteria in B. argentifolii (= B. tabaci biotype B) and its influence on the host insect processes. Hence, as a further pursuit, we examined our laboratory B. tabaci biotypes B and Q for their gut bacteria, whether these two biotypes are differed with each other. Gut bacterial strains isolated by standard surface sterilization method was identified through 16S rRNA gene sequence. Gut bacterial strains of B. tabaci biotypes B and Q and their close relatives retrieved from the public database (NCBI) indicated that the biotype B was less diversified only with four genera viz., Bacillus, Micrococcus, Pseudomonas and Staphylococcus, whereas the biotype Q diversified with six such as Bacillus, Janibacter, Micrococcus, Staphylococcus, Stenotrophomonas, and Streptomyces. Results of the present investigation suggesting that there may be a relationship with gut bacterial strains and susceptibility to insecticides and host plant preference of B. tabaci biotype B and Q.

This study was done to evaluate the susceptibility, systemic effect, residual effect and control effect in each developmental stages of biotype Q of sweetpotato whitefly against insecticides, acetamiprid+spinetoram SC and dinotefuran SG. Two insecticides were showed similar activity against the eggs, and showed higher activity in acetamiprid+spinetoram SC against the nymph and adult. In systemic effect, two insecticides have a similar activity. It was showed higher activity in root zone systemic application than leaf zone systemic application. Residual effect was showed higher in acetamiprid+spinetoram SC (92%) than dinotefuran SG (44 %) at seven days after treatment. Control effect was showed all over 90 % activity at tree- and seven days after treatment. Therefore, these insecticides are expected to control the sweetpotato whitefly effectively.

This study was performed to investigate the feeding behavior of sweetpotato whitefly, Bemisia tabaci using the DC-EPG and the each developmental periods of biotype Q against nine varieties of red pepper. The result was showed that biotype Q did not feed and develop in the Nokkwang variety. In order to analyze the antifeedant, three feeding-preferred varieties (Cheongpungdaegun, Cheonyang, and Sannedeul) and non-preferred variety (Nokkwang) was tested for their sugar compounds using HPLC (ELSD Detector). The detected sugars were erythritol, xylose, xylitol, fructose, glucose, mannitol, and sucrose. In feeding-preferred varieties, the sugar such as erythritol, xylose, and xylitol were present at higher quantity than Nokkwang variety, however, fructose was existed lower quantity than Nokkwang variety. Subsequent bioassay for antifeedant activity, only xylitol showed repelled at lower concentration; however, attracted at higher concentration. Therefore, it is believed that xylitol may play a key role in the variety choice of red pepper by Q biotype of sweetpotato whitefly.

Biotype Q of Sweetpotato whitefly, Bemisia tabaci (Homoptera: Aleyrodidae) was raised in seven tomatoes and eight red pepper varieties; however, biotype B did not grow in red pepper varieties. Rokkusanmaru variety of tomato and Cheongpungdaegun variety of red pepper showed the highest susceptibility to biotype B and Q. HPLC (ELSD Detector) analysis showed that the presence of sugars such as erythritol, xylose, xylitol, fructose, glucose, mannitol, and sucrose in red pepper varieties; erythritol, xylose, fructose, glucose, and mannitol was in tomato varieties. Tomato varieties lacks xylitol and sucrose, which were present in the red pepper varieties. Subsequent bioassay with these two sugars, sucrose did not show significant difference between two biotypes; however, xylitol was showed only repellent effect against B biotype. Therefore, it seems that xylitol may play a key role in the selection of host plant by biotype B of sweetpotato whitefly.

This study was performed to investigate the change of probing and feeding behavior of Q type of B. tabaci according to the decrease of residual effect of two insecticide, emamectin and pyridaben, using EPG technique. Examined the residual activity during 20 days, pyridaben is showed longer than emamectin benzoate. When treated two insecticides onto tomato leaves with the recommended concentration through 20 days, EPG waveforms of Q type of B. tabaci was recorded during three hours compare with the characteristic patterns of feeding behavior between two insecticides such as duration of first probing time, total duration of non-probing phase, total duration of probing phase and total duration of phloem phase. Recorded result from the change in total duration of probing activity to react the two insecticides, pyridaben was showed higher the time of probing activity, however, total duration of phloem phase was appeared low activity. Total duration of phloem phase with passage of days did not show until seven days, however, and gradually increased in emamectin benzoate after 10 days. In conclusion, residual effect between two insecticides was showed more rapidly decreased in emamectin benzoate, however, feeding behavior of Q type of B. tabaci was increased.