Overwintering of Thrips palmi Karny (Thysanoptera: Thripidae) on Jeju Island, Korea

Lee, Gwan-Seok,Lee, Joon-Ho,Song, Jeong-Heub Korean Society of Applied Entomology 2001 Journal of Asia-Pacific Entomology Vol.4 No.1

Field surveys of Thrips palmi Karny on plants during winter seasons from 1995 to 1996 indicated that the thrips could overwinter as an adult stage on Jeju island, the southernmost island of Korea. In both years, overwintering T. palmi adults were collected after the coldest month (Jauary and Fevruary in 1995 and 1996, respectively), especially in the southerm part of the island. The thrips population was very high in december 1996(92.7% of total adults collected), then rapidly decreased from January through April, and slightly increased from May. T. palmi adults were collected from thirty wild plant species in fifteen families and from twelve winter crops in six families. On Stellaria media Vill and Artemisia princeps Pampan., T. palmi were continuously found during the whole winter season. They appeared to be important as overwintering hosts for T. palmi. Sex ratio of the thrips was extremely female bised(98.8%).

Cold hardiness of the palm thrips, Thrips palmi

Youngjin Park,Kwangho Kim,Yonggyun Kim 한국응용곤충학회 2013 한국응용곤충학회 학술대회논문집 Vol.2013 No.10

Cold tolerance of the palm thrips, Thrips palmi Karny, was investigated to predict its survival in field during winter. Supercooling temperatures of T. palmi ranged from -26.4 to -18.4°C. However, exposure to subzero temperatures (from -5°C to -15°C) gave significant mortality to all developmental stages of T. palmi. Thus, T. palmi was determined to be a freeze-susceptible and suffered with cold injury. A brief pre-exposure to a low temperature (4°C) for 7 h significantly increase the cold tolerance of all stages of T. palmi with respect to survival at -10°C and supercooling capacity. A pre-exposure of T. palmi at 4°C significantly increased the survival rate on all developmental stages at -10°C. The rapid cold hardiness (RCH) was dependent on the duration of the pre-exposure period at 4°C in adult stage. Cryoprotectant analysis using an HPLC showed that the pre-exposure treatment increased the adult to synthesize glycerol, trehalose, mannitol, and mannose, at which trehalose represented the highest content. This study suggests that all stages of T. palmi are able to become cold-hardy by RCH, in which several polyols may play crucial roles as cryoprotectant.

Characterization of insecticidal compound from Streptomyces gramineus against Thrips palmi

Sang Hee Kim,Park Dong Hwan,Choi Jae Young,WANG MINGHUI,Liu Siyi,제연호 한국응용곤충학회 2023 Journal of Asia-Pacific Entomology Vol.26 No.4

Thrips palmi, also known as melon thrips, is one of the serious phytophagous sap-sucking insects that not only damages a wide range of crops but also serve as a vector for plant viruses. Actinomycetes have been reported to produce various insecticidal compounds such as spinosad and avermectin, suggesting that secondary metabolites from actinomycetes could be useful biological insecticides. In this study, culture filtrates of 174 actinomycetes isolates were screened for their insecticidal activity against T. palmi. Among them, Streptomyces IMBL-2090 showed superior insecticidal activity with 100% mortality and no acute fish toxicity. Through bioassay-guided fractionation using culture filtrate of IMBL-2090, phenylacetic acid was identified as the major insecticidal substance. These results suggested that Streptomyces IMBL-2090 could be exploited as an effective biological insecticide for control of T. palmi.

Building of entomopathogenic fungal library to manage melon thrips, Thrips palmi Karny

Dongwei Li,Sihyeon Kim,Se Jin Lee,Mi Rong Lee,Jong Cheol Kim,So Eun Park,Tae Young Shin,Jae Su Kim 한국응용곤충학회 2019 한국응용곤충학회 학술대회논문집 Vol.2019 No.04

Melon thrips, Thrips palmi Karny (Thysanoptera: Thripidae) is a worldwide polyphagous pest. The management of this pest have mainly relied on chemical agents. However, the overuse is harmful to the environment and results in insects resistance. Therefore, alternative eco-friendly control methods that have different mode of action, such as biological control, are necessary to overcome the current issue. In this study, we isolated entomopathogenic fungi from Korean soil, and characterized them via morphological and molecular techniques and pathogenicity assay against Tenebrio molitor larvae. The isolated fungi were screened for virulence against T. palmi under laboratory conditions and the results were used to establish a thrips-pathogenic fungal library. The highly virulent isolates were selected and further characterized for optimum culture conditions and application as biopesticide in the field.

Residual contact vial method for the rapid on-site detection of insecticide resistance in Thrips palmi

김민주,김경문,Tian-Bo Ding,김주현,정인홍,권덕호,이시혁 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.2

A residual contact vial plus water (RCVpW) bioassay method, in which water was supplemented to minimize control mortality, was established to monitor insecticide resistance in field populations of the melon thrips, Thrips palmi. In the RCVpW, median lethal doses (LD 50 ) of six insecticides commonly used in T. palmi control, were determined at 8 h post-treatment, using a susceptible RDA strain according to the RCVpW protocol. Diagnostic doses for on-site resistance monitoring of the six insecticides, which were determined as doses twofold higher than required to achieve LD 90 in the RDA strain, were in the range of 0.299 to 164.3 μg −1 cm 2 . Insecticide resistance levels in five field populations of T. palmi were evaluated to test the applicability of RCVpW in monitoring the pest. Although the RDA strain exhibited 100% mortality to diagnostic doses, field populations showed a reduced mortality in response to all test insecticides, indicating different degrees of resistance. In particular, all test field populations exhibited a significantly low mortality in response to spinosad, suggesting a wide distribution of spinosad resistance. Synergistic bioassay revealed that cytochrome P450-mediated metabolic factor is involved in spinosad resistance in the Korean population. Interestingly, an apparently reduced mortality to emamectin benzoate and chlofenapyr was observed in some field populations, perhaps suggesting uneven distribution of resistance to these insecticides in field populations. Our study showed that the RCVpW protocol can be employed both as an on-site resistance monitoring method for major thrip species, and in the selection of appropriate insecticides for their control.

Detection and mechanisms of insecticide resistance in melon thrips (Thrips palmi)

Min Ju Kim,Kyungmun Kim,Tian-Bo Ding,Ju Hyeon Kim,In Hong Jeong,Deok Ho Kwon,Si Hyeock Lee 한국응용곤충학회 2019 한국응용곤충학회 학술대회논문집 Vol.2019 No.04

A residual contact vial plus water (RCVpW) bioassay method was established to monitor insectiside resistance in field populations of the melon thrips, Thrips palmi. Resistance level against six major insecticides were evalutated in five regions to test applicability of RCVpW as an on-site resistance monitoring tool. Reduced mortality in response to six test insecticides were exhibited compared to the RDA susceptable strain showing 100 % mortality, indicating different degree of resistance. An apparently reduced mortality to emamectin benzoate and chlofenapyr was observed in some field populations, suggesting uneven distribution of resistance to these insecticides in field populations. In addition, spinosad resistance was high and widely distributed in the test regions. Synergistic bioassay revealed that cytochrome P450-mediated metabolic factor is involved in spinosad resistance in the Korean population.

Solid cultures of thrips-pathogenic fungi Isaria javanica strains for enhanced conidial productivity and thermotolerance

박소은,김종철,이세진,이미롱,김시현,Dongwei Li,백세현,한지희,김정준,구경봉,신태영,김재수 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.4

Entomopathogenic fungi have great potential to control agricultural and horticultural insect pests, however optimizing conidial production systems to demonstrate high productivity and stability still needs additional efforts for successful field application and industrialization. Although many virulent entomopathogenic fungal isolates have been viewed as potential candidates in a laboratory environment, very few of the isolates are being used in practice for application in agricultural fields as commercial products. I. javanicus is an entomopathogenic fungus that is parasitic to various diverse coleopteran and lepidopteran insects and thought good candidate as biopesticdes. In this work, the basic characteristics of two entomopathogenic fungi, I. javanica FG340 and Pf04, were investigated in morphological examinations, genetic identification, and virulence against Thrips palmi, and then the feasibility of various grains substrates for conidial production was assessed, particularly focusing on conidial productivity and thermotolerance. Isaria javanica FG340 and Pf04 conidia were solid-cultured on 12 grains for 14 days in a Petri dish. Of the tested Italian millet, perilla seed, millet and barley-based cultures showed high conidial production. The four-grain media yielded > 1 × 10 9 conidia/g of I. javanica FG340 and Pf04. Pf04 strain had enhanced thermotolerance up to 45 °C when cultured on Italian millet. In application, it was easy to make a conidial suspension using the cultured grains, and several surfactants were tested to release the conidia. This work suggests several possible inexpensive grain substrates by which to promote conidial production combined with enhanced stability against exposure to high temperature.

Potential risk mapping for range expansion of insect pests with climate change and socio-economic scenario: A case Study of Melon Thrips.

Jinsol Hong,Gwan-Seok Lee,Jung-Joon Park,Kijong Cho 한국응용곤충학회 2017 한국응용곤충학회 학술대회논문집 Vol.2017 No.10

From simple niche models to machine learning methods, there have been intensive efforts to understand the potentialdistribution of species in last two decades. Especially in the agricultural sector, recent SDM, Species Distribution Models,studies highly enthused to predict the potential distribution of invasive species under Climate Change. Beyond the distribution,efforts are needed to assess potential risk caused by the target pest. The Shared Socio-Economic Pathways (SSPs) are scenariosfor climate change impacts and adaptation measures. We used MaxEnt model to predict potential distribution of melonthrips with two RCPs (4.5, 8.5) and three SSPs (SSP1, SSP2, SSP3) scenarios. In agricultural land, the potential distributionof melon thrips increases under climate change, but the impact is reduced with the development-oriented scenario, SSP3.

Biological Control of Thrips palmi (Thysanoptera: Thripidae) with Orius strigicollis (Hemiptera: Anthocoridae) on Cucumber in Plastic Houses in the Southern Region of Korea

Kim, Do-Ik,Park, Jong-Dae,Kim, Seon-Gon,Kim, Sang-Soo,Paik, Chae-Hoon Korean Society of Applied Entomology 2004 Journal of Asia-Pacific Entomology Vol.7 No.3

Field evaluations were conducted to determine the efficacy of Orius strigicollis for biological control of Thrips palmi with different initial density in plastic houses. O. strigicollis released three times after 0, 5, 30, 100 thrips were inoculated per 30 cucumber plants. Three hundred and sixty predators were released in each plot. After inoculation of 5 T. palmi per 30 plants in each plot in plastic houses, T. palmi population increased rapidly with 16.3 individuals per plant in the fourth week, and O. strigicollis could not suppress T. palmi population because O. strigicollis population did not build up quickly. In the plot of 30 thrips inoculation, the density of O. strigicollis increased to 2.1 individuals per plant in the third week and 9.8 individuals per plant in the sixth week. The density of T. palmi increased to 33.8 individuals per plant in the sixth week. In the 100 thrips inoculation plot, the density of O. strigicollis increased to 9 individuals per plant in sixth week, which was similar to that in the 30 thrips inoculation plot. But the density of T. palmi increased rapidly from 2.9 to 384.7 individuals per plant in the sixth week. So, control of T. palmi by O. strigicollis did not appear. In autumn culture, in the 5 thrips inoculation plot, the density of O. strigicollis was so low that it could not suppress thrips density. In the 100 thrips inoculation plot, the density of T. palmi was so high that O. strigicollis could not suppress T. palmi density. In the 30 thrips inoculation plot, the density of O. strigicollis was 4.8 individuals per plant in the sixth week and the thrips population was suppressed. But O. strigicollis could not suppress the thrips population after sixth week because of low temperature and short photoperiod. These results indicate that control of T. palmi using O. strigicollis may be possible on cucumber in the spring culture.

Thrips Species (Thysanoptera: Thripidae) in Winter Season and Their Vernal Activities on Jeju Island, Korea

Lee, Gwan-Seok,Lee, Joon-Ho,Kang, Sang-Hun,Woo, Kun-Suk Korean Society of Applied Entomology 2001 Journal of Asia-Pacific Entomology Vol.4 No.2

Vegetation sampling and sticky trapping were conducted to investigate overwintering thrips species and their vernal activities, respectively, in winter-spring seasons on Jeju island, Korea, from 1994 to 1996. In addition to Thrips palmi Karny, which was reported overwintering on Jeju island by Lee et al. (2001), twelve thrips species belonging to the family Thripidae were found on vegetation during the winter season. Among them, eight species including economically important thrips, Frankliniella intonsa(Trybom), F. occidentalis (Pergande), and T. tabaci Lindeman were found to overwinter on vegetation in the island. Scitothrips dorsalis Hood, however, is uncertatin whether or not it can overwinter on vegetation. Vernal activities of thrips observed by sticky trapping were different among species. All thrips, except for T. palmi, were caught after mid April, and F. intonsa and S. dorsalis were earlier than F. occidentalis and T. tabaci.