Western flower thrips (WFT), Franklinella occidentalis, is a major pest of ornamentals. Mycotized millet grains with entomopathogenic fungi applied to soil of potted marigold plants was tested to target pupating thrips. Two experimental fungal isolates, (Beauveria bassiana [ARS7060] and Metarhizium anisopliae [ERL1171]), were compared with the registered B.bassiana strain GHA and untreated controls in greenhouse caged trials. Mycotized millet grains were mixed into the upper surface of the potting soil in pots of flowering ‘Hero Yellow’ marigolds (4 g/pot). One week after application five mated WFT females were released onto each plant (four plants per cage). At 8 wks post-infestation, the mean total number of thrips per plant was 81 and 90% less in the ERL1171 and ARS 7060 treatments, respectively, than in the controls. The mean numbers of thrips per plant for the control and GHA treatments were not significantly different. Plant damage was 60% less on plants treated with the experimental fungi than the control and GHA treatments. At 10 wks post-application, 75-90% of WFT collected from the treatments were infected with the experimental isolates. These results demonstrate that soil applications of entomopathogenic fungi can reduce WFT populations significantly and prevent damage.

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.

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.

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.

Frankliniella occidentalis Pergande and F. intonsa Trybom (Thysanoptera: Thripidae) are polyphagous insect pests on numerous crops. These two species reduce the crop production in two ways: by sucking sap from the plant parts and by serving as vectors for tospoviruses. In this study, we tried to confirm the previous observation of F. intonsa dominance on certain crops during recent years. Thrips populations were examined on greenhouse strawberry by installing circular yellow sticky cards with black background and on field pepper by destructive sampling of pepper flowers during season of 2012 in Songcheon, Andong. Eighty two to 92% and 3-5% of thrips collected from the both crops were F. intonsa and F. occidentalis respectively. Frankliniella. intonsa was 4-8 times more abundant than F. occidentalis in sticky cards and on pepper flowers. In conclusion, asymmetrical dominance of F. intonsa was found both in strawberry and pepper plant as we found in past on those crops. Underlying reasons such as interspecific competition and climate change were discussed.

In the case of one standard-mum polyvinyl house, the density of F. occidentalis reached its peak in early June and decreased after the chemical control, which was carried out periodically. In the case of another standard-mum polyvinyl house, the density of F. occidentalis increased continuously in spite of the periodical chemical control after planting. In both polyvinyl houses, the density of F. occidentalis began to increase mid-May. The numbers of F. occidentalis collected on a tray with wet paper by heating the flowers of pink, white, and yellow Chrysanthemum standard mums were 18.4, 56.6, and 52.6 after flowering, but in the case of the leaves, the numbers were 7.8, 16.6, and 15.4. Also, the numbers of F. occidentalis collected on a tray with wet paper by heating the buds of pink, white, and yellow Chrysanthemum standard mums were 15.2, 45.8, and 41.6, but in the case of the leaves, the numbers were 2, 8.8 and 3.4. In the Y-tube olfactometer test, the frequency of F. occidentalis’ visits to one side arm of the Y-tube olfactometer was higher in the odor cue of the white flower than of the yellow, red, and violet flowers, but in the other combinations without white flowers, the frequency was higher in the odor cue of the violet and red flowers than of the yellow flowers. In the case of the four-choice olfactometer test, in the same visual cues as the odor cues of the pot mum flowers, the frequency of F. occidentalis was higher in the yellow flower than in the other flowers (white, red, and violet) in all the observation times (10, 15, and 20 minutes). In the case of the visual cues with disturbed odor cues, F. occidentalis preferred the yellow color to the other colors in all the observation times (10, 20, and 40 minutes). F. occidentalis preferred the white color to the other colors when the same odor cues as the flower color were provided, but the odor cue of the yellow flower was provided only without the color cue.

Chrysanthemum flower model trap developed by modifying an artificial yellow chrysanthemum flower was reported to be more attractive to flower thrips than a commercial yellow sticky trap. The installation of the traps (20 traps per 50 m2 plot), especially, reduced the seasonal populations of Frankliniella intonsa Trybom (Thysanoptera: Thripidae) on strawberry flowers in greenhouse by 82% compared to the untreated control. In this study, we tested if the installation of the flower model traps can reduce thrips population on a red pepper field located in Seokdong, Andong. The pepper field was treated two times with pesticides during the period of experiment. The traps were installed in plant canopy at different densities (0, 5, 10, 20 traps) in 20 plots (3×5 m2 each) using a completely randomized design. Population of thrips was examined on the collected pepper flowers from 1 July to 29 July in 2009. Thrips found on the flowers were all F. intonsa. Significance effect of treatment and sampling date was found from repeated-measure analysis of variance. The highest density of traps significantly reduced female and male F. intonsa population by 60% and 46% compared to the control, respectively. However, no difference in immature population was found among the treatments. These results indicate flower model trap can be an additional tool for the management of flower thrips on field red pepper.

Western flower thrips, Frankliniella occidentalis(Perg.), is one of the major pests of lettuce, Lactuca sativa. To develop the economic thresholds for western flower thrips on lettuce, the thrips was inoculated into two types of lettuce, green deeply lobed leaf lettuce which was harvested every week and red frilled & crinkled leaf lettuce which was harvested one time, with a density of 0, 1, 3, 7, 10 thrips per one lettuce after planting 1 week and 3 weeks at the plastic house in 2006, and 0, 1, 3, 5, 7 thrips per one lettuce after planting 1 week in 2007. There was close correlation between the initial thrips density and the marketable quantity of lettuce : y = -155.36x + 3564.7, r2=0.9724('06), y = -167.82x + 3474.5, r2=0.8897('07) in the green deeply lobed leaf lettuce inoculated the thrips after planting 1 week, y = -109.65x + 3549.1, r2=0.9384('06) in the green deeply lobed leaf lettuce inoculated the thrips after planting 3 weeks, y = -197.09x + 3334.9, r2=0.9707('06), y = -244.08x + 3425.9, r2=0.8914('07) in the red frilled & crinkled leaf lettuce inoculated the thrips after planting 1 week, y = -101.07x + 3457.6, r2=0.7334('06) in the red frilled & crinkled leaf lettuce inoculated the thrips after planting 3 weeks. The economic threshold for western flower thrips on lettuce was ranged 0.20～0.30 thrips per one lettuce in the blue type lettuce and 0.14～0.33 thrips per one lettuce in the red type lettuce.

Frankliniella occidentalis Pergande (Thysanoptera: Thripidae) is economically important pest of various crops causing damage through direct feeding and transmitting tospoviruses. In a previous study differential responses of the thrips to various geometrical patterns of yellow sticky card were found. Therefore, in this study, we compared the behavioral responses of the thrips to visual and olfactory cues in cylindrical black box and Y-tube olfactometer, respectively. Multiple or pair wise choice tests were carried out among/between six geometrical patterns of yellow color paper and artificial flowers. The thrips preferred circular shape to other geometrical patterns in multiple choice test. In pair wise choice test between three geometrical patterns, i.e., circular, rectangle, and modified circular, and artificial strawberry flowers, the thrips showed preference to the yellow artificial flower than any other cues. The thrips resided on the yellow artificial flower almost 4 times more than other patterns. In Y-tube olfactometer test, higher number of the thrips chose the arm with p-anisaldehyde and artificial flower compared to the arm with only the artificial flower. Higher number of the thrips also chose the arm containing both visual and real flower odor as compared to arm with the only real flower odor. The potentials and application of these results in the development of attraction traps for the thrips management have been discussed.

Fumigant toxicity of four plant essential oils (muguet flower, patchouli, pennyroyal, spearmint) were tested against the adults of westem flower thrips, Frankliniella occidentalis. Among them, pennyroyal and spearmint oils showed 100% mortality at 1 ㎕/45 ㎖ air dose. Through the constituent analysis using GC and GC-MS, we confirmed that main constituents of pennyroyal oil were pulegone(100.0%), and spearmint oil were β-myrcene(3.5%), limonene(12.1%), carvone(85.4%). Among them, carvone and pulegone showed 100% fumigation at 1 ㎕/45 ㎖ air dose, respectively. It can concluded that two oils aloe potential control agents against F. occidentalis.