• Parasites, Hosts and Diseases
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• v.55 no.2
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• pp.225-228
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• 2017

The ghost ant Tapinoma melanocephalum is a common household pest worldwide. The present study examined the occurrence of the species in urban homes in Korea. During the period of September 2014 to January 2016, T. melanocephalum workers were collected from 58 homes at 29 different localities using bait traps with 10% sugar solution. The species was widely distributed throughout urban homes at 29 different localities, and the indoor occurrence of T. melanocephalum was highest in Seoul (32.7%) and metropolitan areas of Gyeonggi-do (Province) (29.3%). The indoor incidence rate of T. melanocephalum peaked in September (22.8%), remained moderate from October through April, and peaked again in May (15.7%). In contrast, a low incidence was observed from June to August (7.0%). The present study provides evidence that native ants, such as T. melanocephalum, are potential indoor pests of homes in Korea throughout the year.

• International Journal of Industrial Entomology and Biomaterials
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• v.16 no.2
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• pp.93-99
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• 2008

The turnip aphid is a worldwide pest, damaging mainly to crucifers. In order to understand the life parameters of Lipaphis erysimi for the eventual goal of control, the developmental periods, survival rates, lifespan, and fecundity of the species were investigated under five temperature regimes ($15^{\circ}C-35^{\circ}C$). Furthermore, the efficacy of several environment-friendly agricultural materials (EFAMs) that are on the market was subjected to test in order to obtain further accurate information. The developmental period of the turnip aphid nymph was longest at $15^{\circ}C$ as 16.9 days, shortened as temperature goes up to $25^{\circ}C$ (5.4 days), and then somewhat increased at $30^{\circ}C$ (5.9 days), suggesting that the most efficient temperature for nymphal development could be around $25^{\circ}C$. Mortality of the nymphal turnip aphid was obvious at $35^{\circ}C$, whereas it was minimal at other temperature schemes. The longevity of adults shortened as temperature goes up to $30^{\circ}C$. In particular, the maximum lifespan for adults continued for 55 days at $15^{\circ}C$, but shortened to 21 days at $30^{\circ}C$. The total fecundity was 35.7 at $15^{\circ}C$, 81 at $20^{\circ}C$, 64.2 at $25^{\circ}C$, and 6.6 individuals at $30^{\circ}C$, showing the highest fecundity at $20^{\circ}C$. After the turnip aphids were successfully stabilized in indoor environment the insecticidal activity was tested and mortality was determined 12, 24, 36, and 48 hrs after EFAMs are treated. Several on-the-market EFAMs showed more than 90% of insecticidal activity within 24 hrs or 48 hrs, but a few showed less than 90% activity, signifying importance of selection of proper EFAMs.

• International Journal of Industrial Entomology and Biomaterials
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• v.15 no.1
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• pp.87-91
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• 2007

A diverse kind of environment-friendly agricultural materials(EFAM) for the control of insect pests is on the market. These EFAMs are a part of essential sources for the accomplishment of successful, sustainable, and environment-friendly agriculture. Thus, accurate information of these EFAMs is one that required for the success of environment-friendly agriculture, but, in reality, still appropriate information is absolutely in shortage. In this study, we, therefore, tested the efficacy of commercial EFAMs against two lepidopteran insect larvae, the diamondback moth Plutella xylostella(Lepidoptera: plutellidae) and the tobacco cutworm Spodoptera litura(Lepidoptera: Noctuidae). After the two insect pests were successfully stabilized in indoor environment the larvicidal activity was tested at $24{\pm}1^{\circ}C$, relative humidity(RH) of $60{\pm}5%$, and a photoperiod of 16L:8D, and mortality was determined 48 hrs after EFAMs are treated. The EFAMs that showed more than 90% of larvicidal activity were each six among 16 against both P. xylostella and S. litura and only three of them showed consistent larvicidal activity against both species, signifying species specificity of EFAMs and importance of selection of proper EFAMs depending on target insect pest.

• Toxicological Research
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• v.31 no.4
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• pp.331-337
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• 2015

Synthetic pyrethroids (SPs) are the most common pesticides which are recently used for indoor pest control. The widespread use of SPs has resulted in the increased exposure to wild animals and humans. Recently, some SPs are suspected as endocrine disrupting chemicals (EDCs) and have been assessed for their potential estrogenicity by adopting various analyzing assays. In this study, we examined the estrogenic effects of lambda-cyhalothrin (LC) and cypermethrin (CP), the most commonly used pesticides in Korea, using BG-1 ovarian cancer cells expressing estrogen receptors (ERs). To evaluate the estrogenic activities of two SPs, LC and CP, we employed MTT assay and reverse-transcription polymerase chain reaction (RT-PCR) in LC or CP treated BG-1 ovarian cancer cells. In MTT assay, LC ($10^{-6}M$) and CP ($10^{-5}M$) significantly induced the growth of BG-1 cancer cells. LC or CP-induced cell growth was antagonized by addition of ICI 182,720 ($10^{-8}M$), an ER antagonist, suggesting that this effect appears to be mediated by an ER-dependent manner. Moreover, RT-PCR results showed that transcriptional level of cyclin D1, a cell cycle-regulating gene, was significantly up-regulated by LC and CP, while these effects were reversed by co-treatment of ICI 182,780. However, p21, a cyclin D-ckd-4 inhibitor gene, was not altered by LC or CP. Moreover, $ER{\alpha}$ expression was not significantly changed by LC and CP, while down-regulated by E2. Finally, in xenografted mouse model transplanted with human BG-1 ovarian cancer cells, E2 significantly increased the tumor volume compare to a negative control, but LC did not. Taken together, these results suggest that LC and CP may possess estrogenic potentials by stimulating the growth of BG-1 ovarian cancer cells via partially ER signaling pathway associated with cell cycle as did E2, but this estrogenic effect was not found in in vivo mouse model.

• Korean Journal of Agricultural Science
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• v.47 no.1
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• pp.43-58
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• 2020

Mulching plastic is used for the purpose of maintaining soil temperature, moisture, and weed and pest prevention in agriculture. Any remaining plastic after use may contaminate the soil and damage crop growth. To solve this problem, mulching plastic wrappers have been studied and developed, but the actual use rate is quite low due to their poor performance and frequent tearing of the plastic on the field. In this study, we developed a tractor attachable mulching plastic wrapper to minimize the tearing of the mulched plastic. The developed mulching plastic wrapper consists of hydraulic motors and pumps, valves, a microcontroller, and sensors. The collecting speed of the plastic mulch was calculated considering the tractor's travel speed and the radius of the collecting drum. A proportional controller was designed to control the rotating speed of the hydraulic motor as the plastic was wound around the collection drum and the radius increased. The performance of an indoor experiment was quite promising because the difference between the collecting speed predicted by the calculation and the actual collecting speed was 2.71 rpm. Based on a field verification test, the speed difference was max. 14.28 rpm; thus, the, proportional integral derivative (PID) controller needs to be considered to control the drum speed precisely. Another issue was found when the soil covered at the edge of the plastic was hardened or the road surface was uneven, the speed control was unstable, and the plastic was torn. In future research, vibrational plows will be equipped to break-up the harden soil for collecting the plastic smoothly.

• International Journal of Industrial Entomology and Biomaterials
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• v.21 no.1
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• pp.133-137
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• 2010

The perilla leaf pyralid moth, Pyrausta panopealis Walker (Lepidoptera: Pyralidae), is a serious pest damaging to leaf perilla. In order to establish the life parameters of P. panopealis for eventual purpose of control, the developmental span of each stage was investigated under five temperature regimes ($20^{\circ}C{\sim}30^{\circ}C$). The larval period of P. panopealis was longest as 26.8 days at $20^{\circ}C$ and shortened as temperature goes up to $30^{\circ}C$ as 11.3 days. Survivorship of the larval P. panopealis was the highest at $27.5^{\circ}C$ as 82.5%, whereas that of other temperatures ranged from 40% ($20^{\circ}C$) to 60.0% ($30^{\circ}C$), indicating that the P. panopealis appears to favor somewhat higher temperature. In addition to larval period, the duration of egg, prepupal, and pupal period also were shortened sharply as temperature goes up, whereas the duration of adult stage shortened a maximum of only two days as temperature goes up. After the perilla leaf pyralid moths were successfully stabilized in indoor environment the larvicidal efficacy of ten on-the-market environmentfriendly agricultural materials (EFAMs) that were previously selected from the result of other moth species was tested. Seven of the ten tested showed more than 90% of mortality within 12 hrs and reached nearly up to 100% within 24 hrs, but the remaining three showed less than ~70%.

• Korean journal of applied entomology
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• v.60 no.4
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• pp.379-386
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• 2021

Asian gypsy moth, Lymantria dispar asiatica (Lepidoptera: Erebidae), which is an indigenous pest in Korea, a large outbreak has been reported in Gyeonggi-do, Chungcheong-do, and northern Gyeongsangbuk-do from 2019 in forest and nearby downtown areas, causing emotional damage to forests and city dwellers. During the indoor culture of gypsy moth eggs collected in Yecheon, Gyeongbuk in 2021 we found that 79.65% (321/403 of first instar larvae) were died due to Lymantria dispar multiple nucleopolyhedrovirus (LdMNPV) infection. Sequence analyses of 36 gypsy moths collected from 12 regions in Korea using LdMNPV late expression factor-8 (lef-8) and polyhedrin (polh) genes showed a genetic variation of 0.80% and 0.86%, respectively. Comparison to GenBank data showed that the Korean samples were most similar to LdMNPV in Japan, whereas most different to those of Turkey. These results showed a high infection rate of LdMNPV in Korea and LdMNPV is one of the important population regulators of the gypsy moth.

• Korean journal of applied entomology
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• v.62 no.2
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• pp.95-102
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• 2023

The number of households with pets has increased in recent years. Consequently, interest in mites and their odors has increased. In this study, we investigated whether pyrethrum extract and water-soluble phytoncides are effective tick repellents, deodorizing agents, and antibacterial agents. In the tick-climbing test, the pyrethrum extract (23.33 points) and water-soluble phytoncide (22.00 points) showed a high repelling effect. To confirm the tick avoidance effect of the composite extract, a tick climbing test was conducted with a pest control extract, a composite extract (referred to as a sample) containing a water-soluble phytoncide, and a third-party product (control). The sample showed a high avoidance effect (13.00 points and Control 26.67 points. An indoor repellent efficacy test for ticks confirmed that the sample showed an excellent tick-repellent effect (88%) compared to the control (12%). As a result of a deodorization test, ammonia was shown to have a deodorizing effect of 98.3% and trimethylamine of 99.5%, whereas, in the antibacterial test, the E. coli, Staphylococcus aureus, and pneumonia groups showed an antibacterial effect of 99.9%. Combining the results of this study, it is judged that the complex extract including the above material has high utility value as a material that is effective in mite repellents, deodorization, and antibacterial activity.

• Korean journal of applied entomology
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• v.62 no.4
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• pp.355-363
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• 2023

In addition to causing direct feeding damage to a variety of greenhouse crops, Frankliniella occidentalis also inflicts indirect harm by facilitating the transmission of the tomato spotted wilt virus. Historically, the prevention of F. occidentalis infestations has relied heavily on pesticide use. However, this approach has led to significant side effects in agricultural ecosystems, including the development of pest resistance and challenges in effective prevention. In response to these issues, research has been directed towards identifying alternative substances that circumvent the tolerance developed against chemical pesticides. Extracts from sixty-seven medicinal plants were prepared by soaking them in water for 24 hours at room temperature. These extracts were then applied to adult F. occidentalis, with particular attention to moutan extract treatment. This treatment demonstrated a 100% insecticidal effect on the first day. The moutan extract, specifically, was prepared using 50% ethanol, after which the ethanol and water were removed via a rotary evaporator. The resultant product was then lyophilized into a powder and used after being diluted with water. In indoor experiments, a 40% diluted solution was sprayed onto F. occidentalis, exhibiting a 100% insecticidal effect 24 hours post-treatment. Furthermore, a pot test indicated a 78% insecticidal effect on the first day of application. Ongoing research includes the analysis of active substances that demonstrate exceptional insecticidal properties and the conduct of on-site validation tests. The application of the aforementioned extract is anticipated to be effective in the prevention of F. occidentalis infestations.

• Korean journal of applied entomology
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• v.36 no.1
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• pp.77-82
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• 1997

This study was carried out to investigate the developmental characteristics and life cycle of sciarid fly (Lycoriella sp.), an important mushroom pest. The sciarid fly was reared ina growth chamber at 21$\pm$$1^{\circ}C$ and 55$\pm$5% of relative humidity with a 16h high, 8h dark cycle and Flammulina velutipes was used at diet. The egg was oval with 0.17 mm in diameter and 0.27 mm in length. Average egg period was 4 days. Body length of each instar from the 1st to 3rd was 0.7, 1.5, and 4.5, mm. respectively. Average weight of each instar was 1.9, 15.4 and 93.6 $\mu\textrm{g}$, respectively. In the 4th instar larvae, however, developmental characteristics of female and male became different by body length, weight and segment size. Body length and weight of the 4th instar female larvae were 5 mm and 162$\mu\textrm{g}$, and those of the male larvae were 3.5 mm and 90 $\mu\textrm{g}$, respectively. The larval periods of female and male were respectively 13.5 and13 days. Pupal length of female and male was 3.5 and 2.7 mm, and average weight was 136 $\mu\textrm{g}$ and 6.5$\mu\textrm{g}$, respectively. Adults were emerged from female and male pupae on 5.5 and on 5 days after pupation, respectively. Average longevity of male and female were 7 and 5 days, respectively. The weight of female was two-fold heavier than the male. After copulation, female laid approximately 130 to 150 eggs on/in the sporophore of mushroom. In conclusion, total lifespan of male and female were 29 and 28 days, respectively.