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.

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.

Reported herein is the use of mycotized millet grains with entomopathogenic fungi applied to soil to control western flower thrips (WFT), Franklinella occidentalis. The majority of mature larvae move from plants to soil for pupation. Mycotized millet grains with Beauveria bassiana ERL1170 and Metarhizium anisopliae ERL1171 were mixed in the upper layer of potting soil containing a blossomed marigold as a banker plant. B. bassiana GHA, a commercial isolate, served as a control. One week post applicaion 3 mated WFT females were added per plant. At 8 wks post infestation WFT mortality in pots with ERL1170 and ERL1171 treatments was 90% and 81% respectively compared to GHA with 15% mortality. Plants in the two ERL treatments had lower levels of damage. The insecticidal activities were positively associated with the fungal soil colonization. No significant release of fungal innoculum from the potting medium was observed. These results suggest that soil applications of entomopathogenic fungi can reduce WFT populations to significantly low levels by targeting pupae. Application timing and the life cycle of WFT are important considerations.

Daily predation of femlae/male O. sauteri during nymphal development were 4.2/3.9, 11.4/9.5, 14.3/10.8, and 14.7/12.5 at 17, 22, 27, and 32℃, respectively, and consumed 14.3/10.8 thrips, 7.5/7.2 aphids, 45.9/38.8 mites at 27℃, respectively. Adult females ate 42.8 thrips daily during preoviposition period and 63.2 thrips during oviposition period at 27℃. Predation by O. sauteri on F. occidentalis increased as the density of F. occidentalis increased. However, the rate of increase gradually lessened, resembling a Holling’s type II functional response. The attack rate of adult female is higher than that of the 5th nymph. Adult female and 5th nymph of O. sauteri appeared to prefer 2nd larva of F. occidentalis.

Myzus persicae, Heliothis assulta and Frankliniella occidentalis are the most severe pests of pepper in Korea. IPCC (Intergovernmental Panel on Climate Change) reported that the temperature would increase 7℃ at the end of this century. According to the elevated temperature, the pest population will be grow dramatically. We need to predict the pest-population size to maintain good crop productivity. DYMEX and CLIMEX are commercial software developed by CSIRO in Australia, to build and simulate population dynamics models. Using this software, we predicted population dynamics of M. persicae, H. assulta and F. occidentalis applying past climate data (1970) and future climate data (2070) which were generated by National Institute of Meteorological Research (NIMR). The population growth rates of M. persicae, H. assulta and F. occidentalis were 6300, 16 and 950 times, respectively, with 5 degree elevation. Therefore pest management should be conducted intensively in the future.

Myzus persicae, Heliothis assulta and Frankliniella occidentalis are major pepper pests in Korea. The objective of this study was to assess the pepper-yield decrease caused by population change of M. persicae, H. assulta and F. occidentalis. with temperature elevation. It is easy to expect that climate change will increase crop damage caused by pests. Therefore we should predict pest-population dynamics exactly and find the best available strategy for the pest management. Based on the many reported results of temperature development of the three kinds of pest, we simulated the future population dynamics using the computer softwater, DYMEX, developed by CSIRO. The results were that the population sizes and outbreak frequency of 3 kinds pest would increase with global warming. This work may be helpful to establish an effective pest management.

By releasing predatory mite, Amblyseius swirskii Athias-Henriot, with 25 individuals per cucumber plant in a commercial greenhouse (1,600 ㎡), the population of western flower thrips, Frankliniella occidentalis (Pergande), was kept under the economic threshold level. The initial thrips population of 18.3 individuals per leaf decreased to 2.1 individuals per leaf after four weeks, while the number of A. swirskii reached to 16.6 individuals per leaf. It was also observed that at a point where the thrips occurred in high density of about 34.3 individuals per leaf, A. swirskii population built up on the lower part of cucumber plant first, but as time passed the predatory mites moved upward to the top of the plant and aggregated.

Cage experiments by artificial infestations with different initial densities of Frankliniella occidentalis were conducted to analyze damages and develop control thresholds of F. occidentalis on greenhouse eggplant in 2005 and on greenhouse sweet pepper in 2007. In the eggplant experiment, the infestations of F. occidentalis resulted in direct damage on fruit surface and non-marketable fruits which had several thin or thick lines or bleaching patches on the surface. F. occidentalis adults were frequently found on the flowers of eggplants, while nymphs were mainly observed on leaves. The fruit yield of eggplants was not significantly different among experimental plots with different initial density of F. occidentalis. Relationship between % non-marketable fruits among harvested fruits of eggplant and sticky trap catches of F. occidentalis (no. thrips/trap/week) at two weeks before the harvest showed a positive correlation. Using the estimated relationship, the control threshold of F. occidentalis on greenhouse eggplant was estimated at 10 adults per week at two weeks before the harvest when 5% of non-marketable fruit was applied for the gain threshold. In the experiment of sweet pepper, the direct damage by F. occidentalis was observed on the fruit surface and calyx, and the marketable grade of the damaged fruits decreased. The significant yield loss of marketable fruits was found in plots with high initial introduced-densities. There was a high relationship between thrips density and percentage of damaged fruits. Assuming 5% yield loss (non-marketable fruit) for the gain threshold, the control threshold of F. occidentalis on greenhouse sweet pepper was 4.8 adults per trap and 0.9 individuals per flower at two weeks before harvest.

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.

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.

기주식물에 따른 꽃노랑총채벌레의 생태적 특성을 조사한 결과, 가지, 오이, 고추, 토마토의 잎과 꽃잎에서 꽃노랑총채벌레의 발육기간은 고추 잎에서 6.4일로 가장 길었고, 생존율도 고추 잎에서 67%로 가장 낮았다. 오이의 잎에서 암컷의 수명이 16일로 가장 길었고, 꽃잎에서는 8.1일로 가장 짧았다. 꽃노랑총채벌레 암컷 성충은 가지, 오이, 고추, 토마토 중 토마토 꽃잎을 가장 선호하는 것으로 나타났고, 가지 성묘의 잎 위치별 부화 유충수는 중위 잎에 가장 많았다. 가지의 잎과 꽃잎에 대한 꽃노랑총채벌레 암컷 성충의 서식 선호성은 꽃잎을 더 선호하였고, 4개 작물(가지, 오이, 고추, 토마토)중 꽃잎에 대한 서식 선호성은 고추에서 가장 높았다.

국화에서 꽃노랑총채벌레는 4월 상순부터 수확기까지 계속하여 황색끈끈이트랩에 유인되었고, 봄재배에서 4월 하순부터 6월 중순, 가을재배에서는 정식 직후인 8월 중순부터 9월 상순까지 밀도가 높았으며, 봄재배의 피해엽율이 45%수준 가을재배는 35%수준이었다. 이러한 경향은 PVC하우스와 노지 모두 비슷하였으나 꽃당 충수는 노지보다 PVC하우스에서 약간 많았고, 무방제의 경우는 관행방제에 비하여 3배 이상 충의 밀도가 높았다. 꽃노랑총채벌레에 의한 피해엽은 5월 중순부터 관찰되기 시작하여 국화가 생육함에 따라 함께 증가하는 경향으로, 품종에 따라 약간 차이가 있었으나 모두 정의 상관 관계( = 0.9200-0.9887 , p>0.01)가 있었다.