• Korean journal of applied entomology
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• v.41 no.3
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• pp.177-181
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• 2002

This study investigated seasonal occurrence of Frankliniella occidentalis and its damage on chrysanthemum from 1999 to 2000. F. occidentalis adults were attracted to yellow sticky traps from early April to harvesting time in the field. The highest densities were observed from late April to mid-June in spring culture and from mid-August (just after transplanting) to early September in autumn culture respectively. Seasonal fluctuation in a PVC green house was similar to that in the field. Number of insects per flower were higher in the green house than that in the field. Leaf damages due to the insects were observed from mid-May and increased as chrysanthemum grows (R$^2$ = 0.9200-0.9887$\^$**/, p> 0.01).

• Korean journal of applied entomology
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• v.39 no.4
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• pp.267-274
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• 2000

As the pest of the citrus in Cheju, 69 insect species and 5 animal species were investigated during 1996 to 1998. Of these, Panonychus citri, Phyllocnistis citrella, Aphis citricola, Aphis gossypii and Frankliniella occidentalis are major pests. Especially, F. occidentalis and Peridroma saucia are very important species because of increasing damage. The number of pests species injuring leaf, branch, fruit and flower of the citrus are 36, 16, 41 and 2 species respectively. The rate of damaged fruits by pests is 20.5% in 1997 and 18.6% in 1998 and the rate of bad quality fruits is 6.4% and 6.7% respectively.

• Korean journal of applied entomology
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• v.53 no.4
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• pp.485-490
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• 2014

This study was conducted to assess the occurrence and damages by thrips on greenhouse-cultivated fig in Hwaseong, Gyeonggi Province, Korea. We identified the collected species as Thrips tabaci Lindeman, Frankliniella occidentalis Pergande, and F. intonsa Trybom. The density of thrips in the greenhouses during the summer months was monitored using yellow sticky traps; T. tabaci showed the highest density, followed by F. occidentalis and F. intonsa. The damages by thrips were characterized by stunted plant growth because of delayed discoloration of the pericarp, and development of rough fruit surface. Stereomicroscopic observation on the fruit flesh revealed the growth of gray mold at the damaged area, as well as the dead bodies and exuviae of thrips. The rates of fig fruit damages per month, were 18.2%, 9.7%, 2.9%, and 1.3% in July, August, September, and October, respectively.

• Korean Journal of Organic Agriculture
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• v.17 no.2
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• pp.227-236
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• 2009

This research was carried out to investigate the seasonal occurrence of major pests and the effects of releases of natural enemies for biological control of the major pests in eggplant greenhouse. A total of 8 pest species in 7 families were identified. Among these pests, Myzus persicae, Aphis gossypii, Frankliniella occidentalis, Tetranychus urticae and Trialeurodes vaporariorum were the dominant species in eggplant greenhouse. Two aphid species occurred mainly from May to June, but their populations decreased rapidly from July. The population density of F. occidentalis was high from June to July and T. urticae and T. vaporariorum were abundant from July to September during the growing season of eggplant. In the trials of biological control of pests, aphids could be suppressed within the range of $87{\sim}97%$ by two times releases of Chrysopa pallens eggs. F. occidentalis and T. urticae could be suppressed within the range of $76{\sim}90\;and\;87{\sim}91%$ by three times releases of Orius sauteri adults, respectively. The releases of C. pallens eggs and O. sauteri adults were as effective as three times applications of insecticides for the control of aphids, F occidentalis and T. urticae from May to September.

• Korean journal of applied entomology
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• v.45 no.1 s.142
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• pp.45-49
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• 2006

Fumigant toxicity of four plant essential oils (muguet flower, patchouli, pennyroyal, spearmint) were tested against the adults of western flower thrips, Frankliniella occidentalis. Among them, pennyroyal and spearmint oils showed 100% mortality at $1{\mu}{\ell}/45m{\ell}$ 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 $\beta-myrcene(3.5%)$, limonene(12.1%), carvone(85.4%). Among them, carvone and pulegone showed 100% fumigation at $1{\mu}{\ell}/45m{\ell}$ air dose, respectively. It can concluded that two oils are potential control agents against F. occidentalis.

• Korean journal of applied entomology
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• v.45 no.1 s.142
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• pp.1-7
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• 2006

Effectiveness of Orius strigicollis (Poppius) and Amblyseius cucumeris (Oudemans) as natural enemies against thrips were evaluated on greenhouse green pepper, sweet pepper and cucumber respectively. Control efficacy was calculated by the formula, $(D_{control}-D_{treatment})/D_{control}{\times}100$, where $D_{control}$ is the average density of thrips on the plots in which any natural enemy was not released and $D_{treatment}$ is the average density of thrips on the plots in which natural enemies were released respectively. As a result, control efficacies of O. strigicollis against Frankliniella occidentalis (Pergande) on green pepper and sweet pepper were $14.3{\sim}99.5%$ and $21.6{\sim}98.3%$, respectively. In addition, control efficacy of it against Thrips palmi Kany on cucumber was 61.2-74.4%. Control efficacies of A. cucumeris against F. occidentalis on green pepper and sweet pepper were $12.9{\sim}38.3%$ and $17.1{\sim}87.0%$, respectively. Control efficacy of it against T. palmi on cucumber was $90.4{\sim}97.4%$. Field evaluation showed that the prompt applications of natural enemies were effective to reduce the density of thrips. In detail, to control F. occidentalis effectively on green pepper and sweet pepper in spring season, five to six individuals of O. strigicollis per crops should be released three to six times continuously. To control T. palmi effectively on cucumber in autumn, more than 100 individuals of A. cucumeris per crop should be released four times repeatedly.

• Korean journal of applied entomology
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• v.42 no.1
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• pp.35-41
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• 2003

Anthocorid bugs (Orius spp.) are known as polyphagous predators preying on thrips, aphids, mites, eggs of small insects and whiteflies. This study was conducted to investigate the nym-phal development, survival rate, longevity of Orius sauteri adult and oviposition, when nymphs of western flower thrips (Frankliniella occidentalis) and cotton aphid (Aphis gossypii), and eggs of two-spotted spider mite (Tetranychus uritcae) were fed as diets. Nymphal development of female/male O. sauferi fed with F. occidentalis, A. gossypii and T urticae took 12.2/12.8, 13.0/l3.2, and 17.9/17.8 days at 27$^{\circ}C$, respectively, Survival rates during nymphal development were 96.4, 78.4, 73.8%, longevity of female/male adults were 55.9/51.0, 30.2/30.8, and 25.8/25.1 days, and daily oviposition were 5.6, 4.1, and 1.9 eggs, respectively. Oviposition of O. sauteri fed with F. occidentalis usually began 3-4 days after emergence at 27$^{\circ}C$, and reached at its peak of 7-8 eggs female day 20-40 days after emergence.

• Korean journal of applied entomology
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• v.60 no.4
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• pp.387-401
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• 2021

Thrips infesting hot peppers were monitored in greenhouses using yellow sticky traps. In addition, the hot peppers infected with tomato spotted wilt virus (TSWV) were observed during the monitoring period. The flower thrips (Frankliniella intonsa) were initially trapped at a low density just after transplanting seedlings of hot peppers at late March. The western flower thrips (Frankliniella occidentalis) were trapped after mid April. These two thrips represented more than 98% of the total thrips attracted to the traps after May, in which F. intonsa showed higher occurrence frequency than F. occidentalis. The total number of thrips had two peaks at mid May with a small and short-term peak and at June-July with a large and long-term peak. The trapped thrips exhibited inconsistent sex ratios, suggesting a seasonal parthenogenesis. Different geographical populations were varied in cytochrome oxidase I sequences, in which local populations in Andong shared a high sequence similarity. TSWV-infected hot peppers, which might be mediated by these two thrips species, were observed and confirmed by an immunoassay kit and a molecular diagnosis using RT-PCR. In addition, the TSWV was detected in F. occidentalis collected from the infected hot peppers. Three open reading frames (NS_S, N, and NS_M) of the isolated TSWV genomes were sequenced and showed multiple point mutations containing missense mutations among geographical variants. When the isolated TSWV was fed to nonvirulent thrips of F. occidentalis, the virus was detected in both larvae and adults. However, the viral replication occurred in larvae, but not in adults.

• Korean journal of applied entomology
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• v.45 no.1 s.142
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• pp.9-13
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• 2006

Seasonal occurrence of thrips and its damage on fruits were studied at in open field red pepper in Jeonbuk Province. The kind of thrips were Franklinella occidentalis and F. intonsa. The ratio of F. occidentalis was about 30% in periods of survey. Density of thrips increased in late May and showed peak occurrence in early to middle July. The peak occurrence of thrips was appeared at 4 pentad June, 2 pentad July, 3 pentad August, and 4 pentad September. The part of fruit damaged by thrips became discolored and roughed. When turned red, the colors of damaged parts changed from dark brown to yellowish brown. As a result, damage fruits by thrips decreased marketability. The percent of damaged fruits was highest in Imsil at 20.8% in early August. Density of thrips on flowers was highest in middle July.

• Korean journal of applied entomology
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• v.63 no.1
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• pp.43-51
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• 2024

Thrips infest hot peppers (Capsicum annuum) cultivating in open fields and give serious economic damages. This study reports their yearly occurrence from transplanting to harvest at three different places in Andong, an intense hot pepper-cultivating area. Two main occurrence peaks were detected in June and September. Two dominant thrips were the flower flowers, Frankliniella occidentalis and F. intonsa, which comprised of over 87% of the total occurring thrips. Other thrips did not follow the occurrence peaks of the two dominant species. Tomato spotted wilt virus (TSWV) was detected from the dominant two species, in which higher viruliferous rate was recorded in F. intonsa. Although the hot peppers were the resistant varieties against TSWV, some of them cultivating in the fields exhibited a characteristic disease symptom infected by the virus over the growing seasons. TSWV was isolated from the viruliferous thrips and assessed in NSs sequences encoded in S RNA segment of the virus. Compared to the known resistance breaking (RB) strains, the TSWV isolated from the viruliferous thrips in Andong did not show any RB mutations.