Bemisia tabaci is a species complex consisting of at least 40 species which are morphologically indistinguishable. Althoughgenetic diversity of B. tabaci have been studied in many countries, its information is lack in Bangladesh. The COI sequencewas determined from 91 samples collected in Bangladesh and the phylogenetic relationship was constructed. Four crypticspecies (Asia I, Asia II-1, Asia II-5 and Asia II-10) were present in different regions. While both Asia I and Asia II-1was widely distributed in all around the country, Asia II-5 was central and southern regions, and Asia II-10 was onlyin the central region. Otherwise, our results showed that Asia II-5 had the highest haplotype and nucleotide diversity.Genetic groups of B. tabaci in Bangladesh were most similar with those of Thailand, Vietnam, Pakistan, China, and Indiabut did not show any aggressive cryptic species such as MED and MEAM-1.

The sweetpotato whitefly Bemisia tabaci is one of the most serious pests in the greenhouse. They can infest variouscrop plants even in high warm greenhouse condition in summer. To understand the effect of heat acclimation ability ofB. tabaci, mortality was determined at various temperature conditions of the greenhouse. Adult whiteflies survived evenin 63°C in tomato greenhouse. The median lethal temperature (LT50) of the greenhouse colony was 59.9°C however LT50of the lab colony was 47.6°C. The relative expression level of heat shock proteins (hsp23, hsp70 and hsp90) were significantlylower in the greenhouse colony compare to the lab colony. This result suggests B. tabaci has very high thermal adaptability(acclimation) and its mechanism is associated with heat shock protein system.

담배가루이는 경제적으로 매우 중요한 농업 해충들 중의 하나이며, 전세계적으로 40개 이상의 종들로 구성된 종복합군(species complex) 으로 알려져 있다. 본 연구에서는 담배가루이 종복합군의 유전적 변이와 구성하는 종들의 수를 550개의 COI 염기서열들을 바탕으로 재평가하였 다. 담배가루이의 유전적 변이는 0% - 27.8%이며(평균 11.1%), 이는 담배가루이 종복합군이 서로 다른 속들 혹은 아과들에 속하는 다양한 종들 로 구성되어 있음을 나타낸다. 217개 COI 염기서열들을 바탕으로 분석된 계통수는 담배가루이 종복합군이 잠재적인 신종(Java)을 포함한 43개 종들로 구성되어 있고, 이 가운데 9종(Australia, Asia II 1, Asia II 6, Asia II 7, Asia II 10, Mediterranean, New world, New world 2, Sub Saharan Africa 1)의 종내 유전적 변이는 기존의 종구분 한계인 4.0%가 담배가루이 종복합군의 종들을 구분하는데 적합하며, 높은 종내 유전변이를 보이 는 종들은 은밀종과 관련이 있을 것으로 판단된다.

The sweetpotato whitefly Bemisia tabaci is a serious pest and virus vector of many crops. To understand thermal tolerance of B. tabaci at molecular level, effects of rapid and acclimated thermal stress were analyzed by measuring mRNA levels of two heat shock proteins (hsp), hsp23 and hsp90, of B. tabaci using quantitative real-time RT-PCR. Mortality of adult whiteflies were 65.5% by 45°C for 1 h but 100% by 50°C for 1 h. However, mortality by subsequent exposures to 35°C for 1 h then 45°C for 1 h was 43.3%. Comparison between rapid and acclimated heat shock treatments showed that different patterns between hsp23 and hsp90 levels. At acclimated condition, hsp90 was higher but hsp23 was lower than rapid heat shock. The results suggest that the heat acclimation response is possibly advantageous to whiteflies that are often exposed to drastic temperature fluctuations.

담배가루이(Bemisia tabaci)는 600여 종 이상의 넓은 기주 범위를 가지며, 특히 토마토에는 토마토황화잎말림바이러 스(TYLCV: Tomato yellow leaf curl virus)를 매개하여 심각한 피해를 입히는 흡즙성 해충이다. 본 연구에서는 지역에 따른 담배가루이의 유전적 유연관계를 확인하기 위해 기 개발된 8개의 microsatellite marker(Dalmon et al., 2008)를 사용하여 국내 17개 지역 및 인도네시아 2개 지역의 토마토에서 채집한 담배가루이 암컷 성충의 단편분석을 통해 지역 간의 유전적 다양성을 비교하였다. 그 결과 19개 지역에서 평균 allele는 1.875~9.000, 평균 Observed heterozygosity(HO)는 0.134~0.734, 평균 Expected heterozygosity(HE)는 0.184~0.751, 평균 Inbreeding coefficient(FIS)는 0.023~0.880의 범위로 나타났으며, 이러한 유전자형 데이터를 이용하여 유전적 클러스터를 분석한 결과 총 2개의 클러스터로 나눌 수 있었다. 본 연구를 통해 지역 별 다양한 환경 조건에 따라 유전적 구조의 차이가 다르게 나타나는 것을 확인하였으며, 유전적 유연관계 분석을 통해 국·내외 담배가루이 개체군의 유전적 특성을 밝힐 수 있을 것으로 생각된다.

The sweetpotato whitefly Bemisia tabaci (Gennadius) is a serious pest and vector of various virus causing economic losses in a variety of vegetables in Bangladesh as well as worldwide. In the present study, the mtCOI sequence of B. tabaci was analysed using 70 samples collected from different host plants at 12 districts of Bangladesh. Phylogenetic analysis was shown genetic divergence of our samples was 0.12 – 13.97%. There was three independent clusters such as Asia I, Asia II-1 and Asia II-5 genetic groups. Sequence diversity among three groups was 13.97%, 15.07% and 9.67%. Geographic diversity, for example, Asia I distributed in Central and Northern parts, Asia II-5 Central and Southern parts but Asia II-1 were present everywhere in Bangladesh. There was no B and Q aggressive biotypes in Bangladesh. Most Asia I and II was distributed in southeastern countries including Thailand, Vietnam, Pakistan, China and India. Our results provide understanding of genetic diversity of B. tabaci in southeast area.

Loop-mediated isothermal amplification (LAMP) is a rapid, specific, cost-effective detection method by amplifying nucleic acid under isothermal conditions. In this study, we used LAMP for detection of Hamiltonella defensa that lives as a facultive endosymbiont of whitefly ‘Bemisia tabaci’. We designed the Hamiltonella-specific primers by targeting 16S ribosomal RNA gene and validated the specificity of one primer set. To find the optimum temperature for our primer set, the LAMP reaction was held at the temperature, 60℃, 62℃ and 65℃. As a result, 62℃ was the optimum reation temperature for LAMP reaction. Specificity of primer set was tested by the reaction to both Trialeurodes vaporariorum and B. tabaci. After the whole procedure, the amplicons by LAMP were visualized by adding SYBR Green to the reaction tube.

담배가루이(Bemisia tabaci)는 전 세계적으로 600여 종 이상의 기주에 피해를 주며 특히 토마토에 토마토황화잎말림 바이러스(TYLCV: Tomato yellow leaf curl virus)를 매개하여 농가에 심각한 피해를 입히는 주요 해충이다. 국내에는 CO1 marker를 이용한 3개의 putative species가 보고되어 있으나 microsatellite marker를 이용한 이들의 분석은 수행된 바 없다. 본 연구에 사용된 담배가루이 성충은 시설토마토 주산지인 강원(춘천시), 충남(부여군), 경북(안동시), 경남(밀양시), 전북(정읍시), 전남(보성군), 제주(제주시)와 경기 고양시 시설하우스 꽃기린(Euphorbia milii var. splendens)에서 채집하였으며 현미경 하에 암컷 성충만을 분류하여 분석에 사용하였다. 암컷 성충의 gDNA 추출은 Qiagen Gentra Puregen Tissue Kit (Qiagen, USA)를 활용하였으며, 10개의 microsatellite marker를 2개의 multiplex group으로 나누어 PCR분석을 실시하였다. 유전자형 확인을 위한 단편분석을 통해 전국 시설토마토 주산지에서 채집된 담배가루 이의 지역 간 유전적 다양성을 확인하였다.

The sweetpotato whitefly Bemisia tabaci (Gennadius) is one of the most important sap sucking pests causing economic losses in a variety of vegetables in Bangladesh and as well as around the world. In the present study, the mtCOI sequence of B. tabaci was analysed using samples collected from different host plants (Potato, Brinjal, Tomato, Sweet potato, Bean) from district Gazipur, Patuakhali, Rajshahi and Nilphamari of Bangladesh. Phylogenetic analysis of our samples and relative sequences of B. tabaci in NCBI database was shown three independent clusters. Samples in Bangladesh were most similar with those of Thailand, Vietnam, Pakistan, China and India but did not show any B and Q aggressive biotypes.

The sweet potato whitefly, Bemisia tabaci (Gennadius) and the western flower thrips, Frankliniella occidentalis (Pergande) are major insect pests that causes crop damage worldwide by piercing leaves, sucking sap and transmitting numerous plant viruses. A new strategy for IPM, the push–pull method uses a combination of repellent intercrops (push) and alluring trap plants (pull) to manipulate the distribution of insect pests and control their populations. So, we surveyed the responses of these pests of tomato to several plants in green house. Lavandula angustifolia, Petunia hybrid, Ocimum basilicum and Rosmarinus officinalis showed about forty-percent push response to F. occidentalis in tomato. However, Gypsophila paniculata attracted the F. occidentalis in tomato on the contrary. Pelargonium tomentosum showed about fifty-percent push response to B. tabaci in tomato. However, Mentha spicata and Gypsophila paniculata attracted the B. tabaci in tomato. The utilization technique of these plants should be more inspected in further study.

우리는 시설토마토에서 4가지 침투이행성약제가 사용된 가지를 트랩식물로 활용하여 담배가루이 성충의 방제효과를 조사하였다. 침투이 행성약제가 추천된 농도로 사용되었을 때, 담배가루이 성충에 대한 dinotefuran SG 50% 방제효과는 80%로 방제효과가 각각 51.0%, 12.4%, 11.0%인 cyantraniliprole, pyridaben, clothianidin 보다 높았다. 살충효과가 뛰어난 dinotefuran을 농도별로 처리하였을 때, 200 ppm에서 살충률이 88.4%로 가장 효과적이었다. Dinotefuran의 방제효과는 가지에 적용된 약 9일까지 지속되었고 그 이후 담배가루이 밀도는 증가하였 다. 포장실험에서 가지 트랩식물로부터 0, 15, 20 m 떨어진 토마토 신초에서의 담배가루이 밀도가 가장 높았고 5 m와 10 m에서 가장 낮았다. 담배가루이의 밀도가 낮고 dinotefuran SG 50%가 처리된 가지를 10 m 간격으로 투입했을 때, 담배가루이 성충의 밀도가 전체적으로 낮았으며, 또한 담배가루이의 밀도는 하우스 내부보다는 측면에서 밀도가 더 높았고 가지로부터 멀리 떨어진 곳에서 밀도가 높았다. 담배가루이 밀도가 높 고 dinotefuran SG 50%가 처리된 가지를 5 m간격으로 투입했을 때, 담배가루이 밀도가 낮아졌다. 이러한 결과로 볼 때 가지는 시설토마토 재배 시 담배가루이 성충을 유인하는데 효과적인 트랩식물이며 dinotefuran SG 50% 과 함께 사용한다면 담배가루이 밀도를 효과적으로 감소시킬 수 있을 것이다.

본 연구는 토마토에 대하여 가지가 트랩식물로써 담배가루이를 효과적으로 유인할 수 있을지에 대한 잠재성을 평가하였다. 큰망초, 가지, 오이, 토마토에 대한 담배가루이의 선호성을 비교하기 위하여 선택성 조사가 수행되었다. 담배가루이 성충은 후각적인 자극보다는 시각적인 자 극에 더 민감함을 보여주었고 큰망초보다는 오이와 가지를 더 선호하였다. 가지와 오이의 담배가루이 유인률은 각각 82.3%와 82.5% 였다. 가지 는 오이보다 관리측면에서 더 쉽기 때문에 우리는 본 실험에서 오이를 제외하였다. 담배가루이 성충에 대한 가지의 유인률은 토마토의 초장과 같 거나 더 클 때 90% 이상 이었다.

The density of sweetpotato whitefly, Bemisia tabaci, on greenhouse paprika (Capsicum annuum var. angulosum) were determined by counts of the number of B. tabaci per leaflet in Jinju, Gyeungsangnamdo during 2014. Binomial sampling plans were developed based on the relationship between the mean density per leaf (m) and the proportion of leaf infested with less than T B. tabaci per leaf (PT), according to empirical model (ln(m) = α + β(ln(-ln(1-PT))). T was defined as tally threshold, and set to 1, 2, 3, 4, 5 (adults) and 1, 3, 5, 7 (pupae) per leaf in this study. Increasing sample size, regardless of tally threshold, had little effects on the precision of the binomial sampling plan. Increasing sample size had little effect on the precision of the estimated mean regardless of tally thresholds. T=1 was chosen as the best tally threshold for estimating densities of B. tabaci adults based on the precision on the model and T=3 was best tally thresholds in B. tabaci pupae. Using the results obtained in the greenhouse, simulated validation of the developed sampling plan by RVSP (Resampling Validation for Sampling Plan) indicated the suitable results.

The sweetpotato whitelfy Bemisia tabaci distribute worldwide and infests more than 500 species of plants. To determine nutritional stress of whiteflies at molecular level, we identified a full cDNA of glucose regulated protein 78 (grp78) which is known to be respond to nutritional restriction in vertebrate species. GRP78 of B. tabaci was highly conserved motifs of the HSP70 family and the C-terminal motif of KDEL characteristic of endoplasmic reticulum-specific HSPs. Real-time RT-PCR analysis showed that the grp78 level was not changed by thermal stress treatment from 4°C to 40°C for 1 h. However, the grp78 level was proportionally increased to the ingestion of a sucrose solution ranging in concentrations from 0% to 30% in a Parafilm feeding chamber. In addition, the grp78 levels were various by the ingestion of leaves of 10 different plants for 24 h; its level was higher with eggplant and pepper but lower with rice and apple. Our study suggests that the grp78 may have a role for cellular chaperones in relation to nutritional uptake of B. tabaci.

The JpL species is one of the 31 species belonging to the Bemisia tabaci complex and is distributed in two countries, Korea and Japan. To clarify genetic relationships among different populations of the JpL species in Korea, 83 cytochrome oxidase subunit I (COI) sequences generated from 83 individuals collected from eight Korean provinces were analyzed together with published 16 Korean COI sequences. A total of eight haplotypes were detected from the 99 COI sequences, and 82 COI sequences shared one haplotype, hap-2. The remaining 17 COI sequences were assigned to seven haplotypes, hap-1, 3, 4, 5, 6, 7, and 8. The median-joining networks of the eight haplotypes revealed that the Korean JpL species has undergone genetic variations separately according to two groups, Korean Peninsula and Jeju Island. In addition, the phylogenetic trees constructed based on the 99 COI sequences and published seven Japanese COI sequences were divided into two clades: clade(A) consisted of 97 COI sequences from the Korean Peninsula group, and clade(B) consisted of 19 COI sequences from the Jeju Island and Japan groups. Our study suggests that the Korean populations of the JpL species might have spread and be undergoing genetic variations separately according to the two groups, Korean Peninsula and Jeju Island.

Sweet pepper (Capsicum annuum L.) is one of the leading export greenhouse crops in South Korea. Sweetpotato whitefly, Bemisia tabaci Gennadius is one of the major pests on greenhouse pepper. This pest is conventionally managed by synthetic insecticide application, however this management tactic causes the overuse of toxic compounds and the resistance of whiteflies to insecticides. Therefore, the development of environment-friendly natural insecticides is vitally important. In this study, we evaluated the efficacy of three newly-screened insecticidal compounds for B. tabaci (Biotype Q) in laboratory. The insecticidal effects of the compounds were assessed with adult B. tabaci using leaf disc arena established in petri dish. Among the three compounds tested, JS408, a plant extract from Perilla sp., showed significant insecticidal effects on B. tabaci in one hour causing 90% mortality. However, JA408 caused phytotoxicity on sweet pepper leaf resulting in browning dead spots. The new plant-extract JA408 has promising potential as natural insecticidal compound for B. tabaci, but further study must resolve the phytotoxicity issue. Moreover, insecticidal effect should be evaluated under field conditions.

파프리카(Capsicum annuum var. angulosum)의 주요해충인 담배가루이(Bemisia tabaci)의 고정 정확도 수준에서 표본조사법(Fixedprecision sampling plan)을 개발하였다. 개발된 표본 조사법은 파프리카 온실의 담배가루이 방제체계 확립을 위해 공간분포분석, 표본추출 정시선 그리고 의사결정법으로 이루어 졌다. 자료 수집은 식물체를 상단(지상으로부터 180-220 cm), 중단(지상으로부터 80-120 cm), 하단(지상으로부터 30-70 cm)로 나누어 각 위치별 3개의 파프리카 잎에서 담배가루이 성충, 번데기를 관찰하고 그 총 수를 기록하였다. 담배가루이 성충은 식물체의 상부에서 움직이고 신초에 주로 산란하며 일정부분이 하단으로 내려오기 때문에 상단과 하단에 많이 분포하였으며, 번데기의 경우 상부에 알을 낳았지만 식물체가 크면서 알을 낳은 잎이 아랫부분이 되고 부화한 유충은 잎 뒤에 고착 상태로 우화까지 움직임이 거의 없기 때문에 중단과 하단에서 많이 분포하였다. 공간분포분석은 Taylor’s power law (TPL)를 이용하였으며, TPL계수의 차이를 공분산분석(ANCOVA)하여 차이가 없는 경우 자료를 통합하여 계산된 새 TPL 상수값을 이용하여 표본추출 정시선을 구하였다. 그리고 담배가루이 성충과 번데기의 방제밀도수준을 2.0마리와 10.0마리로 설정하여 방제의사를 결정하였다. 마지막으로 분석에 사용하지 않은 독립된 자료를 이용하여 개발된 표본추출법의 유효성을 Resampling Validation for Sampling Plan (RVSP) 프로그램으로 평가한 결과 적합한 정확도를 보였다.

담배가루이(Bemisia tabaci)는 외래해충으로 바이러스벡터로 작용하여, 토마토의 토마토황하잎말림병바이러스(TYLCV)를 비롯한 약 100여종의 바이러스를 매개하는 중요한 해충이다. 본 연구에서는 VIGS vector를 이용하여 담배가루이 방제를 위한 target 유전자들을 선발하기 위 해 gateway system을 이용한 담배가루이 cDNA library 제작을 시도하였다. 첫 번째 방법으로 oligo d(T) primer를 사용하였을 때, 평균 약 1 kb의 insert와 1.4×10 4 cfu의 titer를 확인하였다. 그러나 insert size가 너무 커서 적절하지 않았다. 두 번째 방법으로 attB-N25 random primer를 이 용하고, sonication을 6초 실시하여 다시 진행하였다. 그러나 확인되는 insert size는 다소 컸고, 몇몇은 insert가 너무 작아서 밴드가 확인 되지 않았으며, 1.04×10 5 cfu의 titer를 확인할 수 있었다. 세 번째 방법으로는 oligo d(T) primer를 이용하였고, sonication을 2초 실시하였다. 그 결 과 300 bp~600 bp size의 insert가 확인되었으나, electro transformation을 사용한 첫번째, 두번째 방법에 비해 heat shock transformation을 사용하여 titer가 5.2×10 2 cfu로 매우 낮은 것을 확인 할 수 있었다. 결과적으로 cDNA library를 만들 때 먼저 random primer를 사용하여 First strand를 합성하여 poly A를 제거하고, 다음으로 sonication을 1초 실시하여 300~700 bp정도의 적절한 size의 insert를 생성하고, 마지막으로 electro-transformation을 실시하여 transformation 효율을 높인다면 VIGS vector에 적합한 cDNA library를 만들 수 있을 것으로 사료된다.

A fixed-precision level sampling plan was developed for Bemisia tabaci in paprika greenhouses. A sampling plan consisted spatial distribution analysis, sampling stop line and decision making in order to establish B. tabaci control in paprika greenhouses. Sampling was conducted in two independent greenhouses at same time (GH 1, GH 2). The GH 1 and 2 were surveyed every week for 22 consecutive weeks, sampling locations of each greenhouse were 19 for GH 1, 9 for GH 2, respectively. The plants in the both greenhouse were divided top (200cm from the ground), middle (100cm from the ground), bottom (50cm from the ground) and observed B.tabaci’s adults and B.tabaci’s pupae in three paprika leaves at each position and recorded separately. GH 2 data was used to validate of fixed-precision sampling plan which developed by GH 1 data. In this study, spatial distribution analysis was evaluated using Taylor’s power law with the pooled data of the top and bottom (B.tabaci’s adults), the middle and bottom (B.tabaci’s pupae) in a 1-leaf sampling unit. Decision making is evaluated by maximum & minimum of action threshold according to the condition from several reference, and the value decided by the price of the plants. Using the results obtained in greenhouse, result simulated validation of developed sampling plan by RVSP(Resampling Validation for Sampling Plan) was showed reasonable precision level.

An assessment was made of the fumigant toxicity of 20 constituents from catnip oil and another additional five previously identified compounds of the oils and control efficacy of three experimental spray formulations containing catnip oil (1, 0.5 and 0.1% sprays) to females from B- and neonicotinoid-resistant Q-biotypes of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae). Spathulenol (LC50, 0.39 μg/cm3) and thymol (0.45 μg/cm3) were the most toxic compounds, followed by carvacrol, α-terpineol, nerol, linalool, menthol and eugenol toward Q-biotype females (0.85–1.24 μg/cm3). The toxicity of these compounds was virtually identical toward both biotype females, indicating that the terpenoids and the insecticides (neonicotinoids and dichlorvos) do not share a common mode of action or elicit cross-resistance. The 0.5% spray of oil formulation resulted in > 80% mortality toward both biotype females. Global efforts to reduce the level of toxic synthetic insecticides in the agricultural environment justify further studies on catnip oil-derived materials as potential contact-action fumigants for the control of B. tabaci populations.