Ethyl formate (EF) and phosphine (PH3) is an alternative fumigant to methyl bromide (MB). The egg, nymph, and adult stages of Frankliniella occidentalis in asparagus were examined for the fumigation activity of EF and PH3. The eggs of F. occidentalis were more tolerance than other stages (adults and nymphs) in both EF and PH3. When the EF was treated for 4 hrs at 5℃ and 20℃, the eggs of F. occidentalis were LCT99=98.70 mg/L and LCT99=61.13 mg/L, and adults were LCT99=11.50 mg/L and LCT99=3.18 mg/L, respectively. However, at 5℃ and 20℃, the eggs were LCT99=83.76 mg/L and LCT99=53.6 mg/L, and adults were LCT99=4.58 mg/L and LCT99=3.44 mg/L, respectively for 4 hrs treatment of PH3. The PH3 was not any external phytotoxic damages at the maximum dose (4 mg/L), but the EF caused significant phytotoxicity in asparagus.

Insecticidal susceptibility of Western flower thrips, Frankliniella occidentalis, was investigated under laboratory and greenhouse conditions using commercial insecticides at their recommended concentrations. Neonicotinoid insecticides, especially acetamiprid SP, clothianidin SC, imidacloprid WP and thiacloprid WG were not toxic to F. occidentalis collected from horticultural crops. Excepting the insecticide of spinosin or pyrrole class, there was a little class of insecticides for the effective control of F. occidentalis in horticultural crop areas. Considering all the results in this study, spinosin insecticides including over 4 and 10% of spinetoram and spinosad, and pyrrole insecticide including over 5% of chlorfenapyr should be recommended for the effective control of F. occidentalis

Phosphine(PH3) is very effective fumigant and is widely used to control pests. Oxygen treatment was found to enhance phosphine toxicity and reduce fumigation time. We researched the insecticidal activities and synergistic effects of oxygen with phosphine(PH3) against on adult stage of 6 agricultural pests as Frankliniella occidentalis, F. intonsa, Pseudococcus comstocki, Planococcus citri, Myzus persicae and Tetranychus urticae. Adults F. occidentalis, F. intonsa, P. comstocki and P. citri was highly susceptible to PH3 at 2mg/L for 2h treatment. However, M. persicae and T. urticae were showed very low fumigation effects at 2mg/L for 2h treatment. These 2 pests were treated with PH3 to increase the times (16h and 20h). And we also researched the synergistic effects of PH3 under controlled atmospheres of 50% and 80% oxygen(O2). Increase of the time and atmospheric oxygen showed improving activities of the PH3 in the 2 agricultural pests. Therefore, PH3 is an effective fumigant against F. occidentalis, F. intonsa, P. comstocki and P. citri, and its synergistic effect with oxygen is effective to control M. persicae and T. urticae. PH3 with oxygen could be useful for managing the agricultural and quarantine pests.

최근 지역적으로 나타나고 있는 침입종인 꽃노랑총채벌래[Frakliniella occidentalis (Pergande) (Thysanoptera: Thripidae)]의 밀도 감소 현상이 토착종이면서 동소종(sympatric species)인 대만총채벌레[F. intonsa (Trybom)]에 의한 생물적 저항성과 환경 요인에 의한 비생물적 저항성이 나타난 결과라는 가설을 세우고 이를 검증하였다. 대만총채벌레는 꽃노랑총채벌레에 비해 발육률이 빠르며 성충 수명, 생식률(R0), 내적 자연 증가율(rm) 모두 높았다. 또한 경쟁 상태에서도 대만총채벌레는 꽃노랑총채벌레에 비해 수명과 생식에서 영향을 상대적으로 덜 받았으며, 특히 두 종간의 행동 관찰 실험에서는 대만총채벌레 의 섭식시간뿐만 아니라 먹이자원을 경계하는 시간이 각각 1.3과 42.8배 더 길어 두 종간 간섭경쟁이 있었다. 온도와 습도를 달리한 환경 조합에서 대만총채벌레가 꽃노랑총채벌레에 비해 고습 조건에서 생존율이 더 높았다. 다만, 대만총채벌레 는 꽃노랑총채벌레에 비해 살충제에 대한 감수성이 높았다. 이상의 결과로 최근 꽃노랑총채벌레의 지역적 밀도 감소 효과는 경쟁종인 대만총채벌레에 비해 낮은 내적 자연 증가율과 간섭경쟁에 의해 나타난 현상으로 판단된다. 다만, 더 넓은 지역에 대한 조사와 먹이 식물과 천적에 의한 영향 등에 대한 추가 연구가 필요하다.

The toxicity of cypress (Cupressus sempervirens) and howood (Cinnamomum camphora) essential oils, and its constituents to adult western flower thrips, Frankliniella occidentalis using leaf-dipping bioassay and vapour-phase toxicity bioassays. Both cypress and howood essential oils were toxic to western flower thrips. The most active principles were determined to be linalool, linalool oxide, cis-linalool oxide, trans-linalool oxide, camphor, and 1,8-cineole from cypress and howood essential oils. Linalool (24h LC50, 0.030 µg/cm2), linalool oxide (24h LC50, 0.036 µg/cm2), cis-linalool oxide (24h LC50, 0.043 µg/cm2), trans-linalool oxide (24h LC50, 0.045 µg/cm2), and camphor (24h LC50, 0.10 µg/cm2) were the most toxic. Potent toxicity was also observed with 1,8-cineole, a-pinene, d-limonene, a-terpinene, cinnamaldehyde, b-pinene, 3-carene a-terpineol, camphene, and terpineol (24h LC50, 0.33–0.65 µg/cm2). The spray bioassy of cypress and howood oil formulation (500 ppm) resulted in > 80% mortality toward western flower thrips population. Global efforts to reduce the level of toxic synthetic insecticides in the agricultural environment justify further studies on cypress and howood essential oil-derived materials as potential contact-action fumigants for the control of western flower thrips populations.

The western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), has been considered as a major thrips species after its invasion in 1993 in Korea although recently F. intonsa (Trybom) was found as a dominant species locally. To explain their asymmetrical abundance in the field, we hypothesized differential insecticide susceptibility of both thrips species as an underlying mechanism. Laboratory assays were conducted to know their susceptibility to different pesticides including chlorfenapyr, chlorpyrifos, thiamethoxam, spinosad, s-metolachlor, and metalaxyl by direct spray, residue, and oral ingestion. Results showed that both thrips species were highly susceptible to chlorfenapyr and mortality reached 100% within 12 hours in F. occidentalis in all the assays while 9 hours in F. intonsa in direct spray and residual assays. The LT50[h] values of tested insecticides were significantly lower than that of herbicide or fungicide regardless of exposure methods except metalaxyl from direct spray. The insecticides tested here differed considerably in species specific toxicity, and F. intonsa is generally more susceptible to the insecticides irrespective of exposure methods.

Frankliniella occidentalis (Pergande) is an anthophilus pest of many greenhouse and field crops worldwide. We compared the influence of constant (27.3ºC) and fluctuating temperatures (23.8 to 31.5ºC, with an average of 27.3ºC) on the life table characteristics of F. occidentalis held at a 16:8 h L:D photoperiod and 45 ± 5% RH. The development times from egg to adult of F. occidentalis were significantly affected by temperature fluctuation and sex. Survival of immature life stages was higher under fluctuating than constant temperature. Total first instar larvae/female was not significantly different (58.7 at constant and 60.5 at fluctuating temperatures) but daily production of first instars was higher in constant temperature than fluctuating temperatures (3.3 at constant temperature and 3.1 at fluctuating temperatures). The off-spring sex ratio was not significantly different between constant and fluctuating temperatures. The intrinsic rate of natural increase (rm), net reproductive rate (R0), finite rate of increase (λ), mean generation time (tG), and doubling time (tD) were affected significantly by fluctuation of temperature. The intrinsic rate of natural increase of F. occidentalis was higher in constant temperature (0.1808) than did in fluctuation of temperatures (0.1733). Thus, this study show that variable temperatures influence population growth rates of F. occidentalis.

Transcriptome analysis was conducted for the identification of genes associated with insecticide resistance in Frankliniella occidentalis. Resistant strain (FO_RDAHC) exhibited 39.2- ~ 533-fold resistance to acrinathrin, spinosad, emmamectin benzoate and thiamethoxam compared with a susceptible FO_RDA strain. Average 7.6 million reads (± 5,068,895 reads) were obtained from the pyrosequencing and were assembled into the draft CDS database. Gene annotation was conducted by BLAST (UniProt), Pfam, FUNCAT and COG analysis. In the deferentially expressed gene (DEG) analysis, 838 genes were up-regulated and 815 genes were down-regulated over 2-fold ratio in FO_RDAHC strain. Highly up-regulated genes included genes encoding several cuticle-related proteins, cytochrome P450s, esterases and transporter genes. An autotransporter protein gene exhibited the highest up-regulation (596 fold) whereas a GMC oxido-reductase revealed the highest down-regulation (12 fold). Further study would be necessary to validate the actual transcript levels of DEGs and to investigate their functional roles in insecticide resistance.

Chemical control is the indispensable part of insect pest management. However, due to overuse of pesticides, the emergence of resistance to pests and environmental pollution problems are appeared. In order to solve these problems, the need of integrated pest management (IPM) has emerged. The IPM means that the pest density should be controlled and maintained to avoid any economic loss, also to minimize any side effects to the human beings and environment using appropriate control methods. In order to do successful IPM, sampling plan should be prepared. Sampling plan consists of monitoring, density estimation and decision making of target insect pests in certain crop field including the knowledge of spatial distribution. Tabaco whitefly, Bemisia tabaci, and Western flower thrips, Frankliniella occidentalis, are serious insect pests in paprika greenhouses. We selected two paprika greenhouses with different sizes (12,000 m2 and 4,000 m2). Insect pests monitoring was evaluated from January 24, 2014 to June 27, 2014. Two monitoring methods are used to develop sampling plans, one is visual survey for B. tabaci population, and the other is using sticky trap for F. occidentalis population, respectively. We calculated spatial distribution using Taylor’s Power Law (TPL). In visual survey results, TPL showed that adults and pupae of B. tabaci were aggregated in paprika greenhouses. And in trap survey results, F. occidentalis was also aggregated with different scale of the slope of TPL equation. In density estimation, the more density of insect pests, the less samples were required. Moreover, the more accuracy, the more samples were required for stop sampling in greenhouses. We selected hypothetic action threshold of 0.3 and 5 for decision making. As a result, if the action threshold is increased, the maximum sample number is decreased

An easy and rapid resistance detection protocol for the Western flower thrips Frankliniella occidentalis was established based on the residual contact vial bioassay (RCV), in which insecticide resistance levels can be estimated at 8 h-post treatment of diagnostic doses. The RDA strain was used as a reference susceptible strain, which has been reared under laboratory conditions over 10 years without exposure to any insecticides. Seven insecticides were tested for the determination of diagnostic dose. Among them, five insecticides (chlorfenapyr, acrinathrin, spinosad, emmamectin benzoate and thiamethoxam, ranged as 0.03 ~ 0.42 μg-1cm2) were applicable to the RCV. However, two insecticides (omethoate and imidacloprid) were not able to be used for the RCV because the treated inner surface of glass vials by these insecticides were too viscous, causing non-specific mortality. The RCV detection kit was employed for the estimation of resistance levels for the five insecticides in five local populations. Almost field-collected populations revealed high levels of resistance to the four insecticides (acrinathrin, spinosad, emmamectin benzoate and thiamethoxam) by showing less than 50% mortality. The baseline resistance detection by RCV method will facilitate the selection of proper insecticides for farmers to manage insecticide resistant-populations of F. occidentalis.

최근 국내 포도원에서 과실 표면에 구름모양의 흰색 얼룩이 자주 발견되고 있으나, 그 원인에 대해 명확히 알려진 바가 없어 방제대책을 세우지 못하고 있는 실정이다. 흰색의 달무리 반점은 포도 과실 표면에 부정형으로 퍼져 있으며, 그 중앙에는 총채벌레가 산란할 때 만들어진 작은 구멍의 상처가 남아 있다. 이 상처부위는 시간이 지나면서 코르크화되고 표피세포와 분리되어 딱지로 남거나 떨어져 나가게 된다. 이러한 증상은 총채벌레의 섭식이나 노린재의 흡즙에 의한 상처와는 구별된다. 산란구멍에서 발견한 총채벌레 알껍질에서 DNA를 추출하여 ITS2 부위의 염기 서열을 PCR-RFLP 방법으로 분자동정을 실시한 결과 꽃노랑총채벌레의 것으로 확인되었다. 미토콘드리아 COI 염기서열은 이러한 분자 동정 결과를 재확인하여 주었다. 본 연구결과는 포도 과피에 꽃노랑총채벌레 산란에 의해 유발되는 독특한 피해 증상에 대한 정확한 정보를 제공하며 포도원에서 이 해충에 대한 방제전략 수립에 도움이 될 것으로 여겨진다.

This paper studies on the effects of new biological control system, particularly on banker plants of Orius laevigatus to control Frankliniella occidentalis on rose. Orius banker plants for Frankliniella occidentalis were investigated under the conditions of photoperiod 16L:8D, 70 ± 5% RH and 22 ± 2oC. Three types of plants(Sedum sarmentosum, ortulaca grandiflora, Mentha rotundifolia) were used to effectiveness verification of egg taking. And P. grandiflora has been selected as the banker plants for O. laevigatus. Result from this banker plants clearly demonstrated that the population of F. occidentalis was kept under the economic threshold level (1.9 per flower).

Frankliniella occidentalis (Pergande) and F. intonsa (Trybom) have been shown asymmetrical occurrence pattern in pepper and strawberry fields. To explain this phenomenon, interactive influence of temperatures (20, 25, and 30ºC) and relative humidities [Low (50-55%), Medium (70-75%), and High (90-95%)] were assessed on pupal and adult stage of the two thrips species. In pupal stage, mortality of both species decreased as the humidity increased without significant difference between the species. Also, pupal duration of the two thrips decreased as RH increased from low to high in all the temperatures tested, but significantly shorter duration was found in F. intonsa. In adult stage, F. intonsa survived better than F. occidentalis only in high humidity at both 20 and 25ºC. Frankliniella intonsa survived 2.5 and 2.4 times longer as RH increased from low to high at 20 and 25ºC, respectively, whereas F. occidentalis survived 1.8 and 1.6 times longer, respectively. In conclusion, both pupae and adults of F. intonsa performed better at higher RH condition compared to F. occidentalis. Thus, difference in relative susceptibility to changing environmental condition can be one of the underlying mechanisms for the differential occurrence pattern in the fields.

Temperature is known to play a crucial role in the population dynamics of insects. Insects have evolved different mechanisms to resist unfavorable temperatures. In recent years, western flower thrips (WFTs), Frankliniella occidentalis (Pergande) have caused serious damage to vegetable crops, so that, a study about the effects of heat stress on the thrips species is warranted. We exposed various developmental stages of WFTs to 41°C, 43°C, or 45°C for 2 h to determine the effects of heat stress on survival rates, the parental reproduction, and its offspring, the activity of acetylcholinesterase and the trehalose level. Prepupae and pupae have the highest level against heat resistance than larvae and adults with higher survival rates after exposure at 41 or 43°C for 2h, but that of adults was higher at 45°C. The survival rates of larvae were lowest. Longevity of female adults and the quantity of larvae and adults in the first generation decreased significantly after exposure to high temperature. Activities of acetylcholinesterase were significant higher after heat stress treated, but the activity of acetylcholinesterase of pupa was significant lower after been exposed to 45°C for 2h. The trehalose levels in different developmental stages were significant lower after heat stress treatment. The activity of acetylcholinesterase and the trehalose level in the first progeny generation changed obviously after exposure the parental individual. These results support the hypothesis that heat stress may be used to control WFTs.

Studies have reported differential attractiveness of yellow, white or blue sticky cards to greenhouse pests, especially to Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) and Trialeurodes vaporariorum Westwood (Homoptera: Alyerodidae). The main aim of this study was to determine whether yellow or blue sticky card offers a better option in monitoring or mass trapping these sympatric greenhouse pests. Laboratory study that included a multiple choice and no-choice tests to observe the attractiveness of blue, yellow, white or green sticky card to F. occidentalis and T. vaporariorum was conducted. Also, a glasshouse study was conducted to determine better composite attractiveness of yellow or blue sticky card. F. occidentalis showed higher preference to blue and yellow sticky cards in laboratory study and blue captured the highest number of F. occidentalis in glasshouse followed by the yellow. However, while the blue sticky card captured few T. vaporariorum, the yellow sticky card captured the highest number of T. vaporariorum in both laboratory and glasshouse tests. Since yellow sticky card received composite affinity of both F. occidentalis and T. vaporariorum, placement of yellow sticky card for the greenhouse pests, rather than blue or yellow targeted to individual species, is recommended for economical and optimal monitoring and/or mass trapping success of the tested greenhouse pests.

꽃노랑총채벌레는 꽃을 선호하며 국화의 주요해충이다. olfactometer를 이용하여 국화가 꽃노랑총채벌레를 유인하는 트랩식물로서 효용가치가 있는지를 조사하였다. 유리온실에 심겨져 있던 스텐다드국화의 화색별 꽃노랑총채벌레의 밀도를 타락법을 이용하여 조사한 결과, 개화시기의 경우에는 핑크색, 흰색, 노랑색의 꽃에서 각각 18.4, 56.6, 52.6 마리였고, 잎에서는 7.8, 16.6, 15.4 마리가 채집되었다. 꽃봉오리 형성시기의 경우에는 꽃봉오리에서 15.2, 45.8, 41.6 마리, 잎에서는2, 8.8, 3.4 마리였다. Y-tube olfactometer 시험에서 선호하는 쪽으로 향하는 꽃노랑 총채벌레의 수는 노랑색에 대하여 빨강색, 보라색, 흰색 꽃의 후각반응을 조사한 결과, 분명한 차이가 없었다. 4-way olfactometer 시험의 경우, 냄새와 동일한 시각자극이 주어졌을 때 꽃노랑총채벌레의 빈도수는 빨강색(1.3), 보라색(3.7)흰색(2.0) 보다 노랑색(10.7)을 선호하였고, 후각적 자극이 교란된 시각적 반응에서도 빨강색 (3.3), 보라색 (1.3), 흰색 (3.0) 보다 노랑색 (10.0)을 선호하였다. 노랑색의 시각적 자극만 제외하고 다른 꽃의 시각적인 자극과 동일한 후각적 자극을 주었을 경우에는 빨강색 (4.7), 보라색 (4.7), 노랑색 (2.0) 보다 흰색(8.3)을 선호하였다. 꽃노랑총 채벌레는 꽃이 개화하기 전에는 꽃의 후각적인 자극에 먼저 반응하여 꽃봉우리로 이동하고 개화되었을 때에는 꽃의 색깔에 더 잘 반응하여 노랑색꽃을 선호하는 것으로 보아 후각적인 자극보다는 시각적인 자극에 더 잘 반응하였다.

오이에서 가장 피해가 심한 해충인 목화진딧물과 꽃노랑총채벌레에 방제를 위하여 사용하고 있는 천적인 콜레마니진디벌과 미끌애꽃노린재에 대하여 노균병과 흰가루병 약제의 저독성을 평가하여 살균제와 동시에 활용한 목화진딧물과 꽃노랑총채벌레에 대한 천적의 방제효과를 조사하였다. 47종 살균제 중 DBEDC, hexaconazole, pyraclostrobin, tribasic copper sulfate, triflumizole, chlorothalonil, flusilazole, folpet, carbendazim+diethofencarb, cymoxanil+fenamidone, trifloxystrobin은 콜레마니진디벌 머미에 50% 이상의 독성을 보였고 저독성 살균제 중 azoxystrobin이 노균병과 흰가루병을 동시에 방제할 수 있어 천적과의 동시활용 약제로 선발하였다. 꽃노랑총채벌레와 목화진딧물은 천안과 공주에서 4월 상순 동시에 급격히 밀도가 증가하였고, azoxystrobin 50% 액상수화제를 10일간격으로 계속 방제 하면서 콜레마니진디벌을 진딧물 발생초기 1주간격 3회, 미끌애꽃노린재를 발생초기 1주간격 3회 방사 후 천적 밀도를 조사한 결과 목화진딧물과 꽃노랑총채벌레의 밀도를 억제하면서 콜레마니진디벌 머미는 하엽당 최대 18마리, 미끌애꽃노린재는 꽃당 0.5마리를 나타내어 azoxystrobin이 콜레마니진디벌과 미끌애꽃노린재의 밀도형성에 악영향을 주지 않았다. 시설오이에서 콜레마니진디벌과 미끌애꽃노린재에 안전한 선택약제와 천적을 동시 이용할 경우 효과적인 진딧물과 총채벌레 방제가 가능할 것이다.

F. occidentalis causes to decrease the yield of chrysanthemum flower economically because it is the major crop pest injuring the flower directly at flowering period in chrysanthemum artificial houses. The control of it with chemicals is very difficult because the resistance of it to chemicals is so high. F. occidentalis began to occur at early-May and increased rapidly mid-May after in standard chrysanthemum artificial houses, Yesan, Chungcheongnam-do. In case of a farm, the density of it increased continuously in spite of chemical control . The times of chemical control to depress the density of it was 6 or 7th for cultivation period of chrysanthemum. We put the flowering yellow pot-mum already (trap plant attracting F. occidentalis) in standard chrysanthemum PVC-houses and set the yellow sticky cards up at an interval of 5m from trap plant(TP). The more yellow sticky trap near to trap plant, the more F. occidentalis was attracted to yellow sticky trap. TP was more attractive to adult F. occidentalis up to distances of 10m. The numbers of it attracted to yellow sticky traps at different distance from TP was not different significantly when standard chrysanthemum bloomed. We put the TP in standard chrysanthumum PVC-house at an distance of 20m and released the natural enemies (Orius laevigatus) on TP at 3 times, an interval of 7 days. And then we set yellow sticky traps up at an distance of 5m from TP and compared the plot with TP+natural enemy(NE) to the plot without them. The density of F. occidentalis was rather lower at TP+NE plot than the plot without at the formative period of flower bud of standard chrysanthemum. Therefore, The yellow flowering chrysanthemum possesses great value of TP attracting F. occidentalis in chrysanthumum PVC-house up to flowering period of cultivating chrysanthemum, and if it is used with natural enemy and chemicals simultaneously, farmers can minimize the quantity of chemicals used.

Frankliniella occidentalis (Pergande) and Frankliniella intonsa (Trybom) (Thysanoptera: Thripidae) are sympatric thrips species infesting crops including strawberry and pepper. Recently, F. intonsa was found as a dominant species locally even though F. occidentalis has been considered as a major species in Korea. We suggested interspecific competition as a underlying mechanism for the asymmetrical abundance. Effect of the competition on adult reproduction and longevity of the two thrips species was assessed in leaf cage and microtube arena, respectively. The number of reproduced progeny was reduced by 79% for F. occidentalis and only 43% for F. intonsa in competition condition. The mean longevity was also reduced greater in F. occidentalis (by 41%) than in F. intonsa (23%). Based on these results, it is probable that interference competition exists between the two species, and F. intonsa is better competitor than F. occidentalis. Therefore, interspecific competition might affect field occurrence pattern of the two thrips species.