• Korean journal of applied entomology
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• v.60 no.2
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• pp.185-191
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• 2021

A Quarantine Pest Research Facility (QPRF) had been build in Animal and Plant Quarantine Agency and designed to ensure alien pests are safety contained inside the laboratory. Functions of QPRF including insect rearing, research, and physical containment facility were verified to check suitability as a research laboratory using the beet armyworm, Spodoptera exigua. As insect rearing and laboratory facility, S. exigua completed its development for 32.2 days at 25℃. Egg hatching, pupation, and adult eclosion showed 80, 86.6, and 90%. Two pesticides, fluxametamide and hydramethylnon showed high susceptibility against S. exigua larvae by spraying and dipping methods. As physical containment facility, male adults, which were artificially released from laboratory, did not capture in delta trap installed sex pheromone lure during winter season. Based on these results, QPRF will be used for study on alien insect species.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.51-62
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• 2022

Numerous insect pests threaten the Korean orchard industry through feeding on various tissues of fruit trees. Generally, the control of economically important orchard pests is based on the use of chemical insecticides. Owing to growing concerns regarding the environmental and human health effects of insecticides, environment-friendly pest control strategies are urgently needed. Pheromones of orchard pests could lead to an environmentally safe control system based on mating disruption or mass trapping. This review summarizes the functions and compounds of known pheromones from 51 orchard pests in Korea. The pheromones identified to date from 14 species in the families Miridae, Aphididae, Diaspididae, Pseudococcidae, Rutelidae, Cecidomyiidae, and Eurytomidae and 26 species in the order Lepidoptera are female-produced sex pheromones that attract only males. In contrast, all known examples for 11 species in the families Alydidae, Pentatomidae, Thripidae and Cerambycidae are male-produced aggregation pheromones that attract both sexes. Research on pheromones in new pests, kairomones in key orchard pests, mating disruption dispensers to generate prolonged release of the pheromones, and trap design and trap location for mass trapping will be required for the expanded use of pheromones and other semiochemicals in orchard pest management in the future.

• Korean journal of applied entomology
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• v.53 no.4
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• pp.355-365
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• 2014

It has been unclear whether the diamondback moth, Plutella xylostella can overwinter in Korean field conditions. This study determined overwintering conditions of P. xylostella by conducting field exposure tests based on its cold tolerance and monitoring overwintering populations by direct examination of overwintering larval habitats and capturing adults with sex pheromone traps. In addition, the overwintering populations were analyzed using polymorphic genetic markers to trace their sources. When all immature stages of P. xylostella were exposed to $-5^{\circ}C$, which was the temperature much above their supercooling points, they significantly suffered with direct cold injuries, where larval stage was most tolerant to the cold injury. However, the exposure to $5^{\circ}C$ for a long period (4 weeks) did not give any significant cold injury to nonfeeding stages, while this treatment gave lethality to larval stage without diet. When all developmental stages of P. xylostella were exposed to open field conditions during winter, they exhibited significant decreases of survival rates. However, some protected and indoor conditions reduced the cold injuries and the diet provision significantly increased larval survival rates. Adult monitoring with sex pheromone during winter period indicated that the first captures were observed at similar periods at different locations (${\approx}260$ Km apart). The overwintering adults were captured until early April. Genetic variation of these overwintering populations was analyzed with polymorphic molecular markers, indicating significant genetic divergences among the overwintering populations. This study indicates that P. xylostella can overwinter in southern Korean fields or some protected greenhouses with host plants.

• Korean journal of applied entomology
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• v.62 no.4
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• pp.227-243
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• 2023

The Asiatic pink stem borer, Sesamia inferens (Walker, 1856) (Lepidoptera: Noctuidae) is a pest that attacks rice stems. In this study, we estimated the annual generation of insect in several regions of the Republic of Korea. Adult trapping using a sex pheromone trap detected the occurrence of S. inferens adults in the three northernmost areas around 38° latitude and showed that the insect inhabits all of Korea. In most areas investigated, the seasons of the adult generations estimated using the single-sine degree-day model did not deviate from the corresponding observed seasons of adult occurrence. We estimated that the overwintering larvae hypothetically-estimated using the model could be originated from the last generation of adults. When larvae collected in paddy fields during the autumn season in a few middle and southern areas were reared at 25℃, ca. 70% of pupae did not show additional larval molting before their pupation. All larvae collected in early March in a southern area (Goseong, Gyeongsangnam-do) pupated without additional larval molting when reared at 25℃. Based on these results, we presumed that S. inferens could overwinter as mainly the last instar larval stage in the area. Taken together, we conclude that S. inferens primarily has two generations per year in areas around 38° latitude, and three generations in the areas between 35.3° and 37.3° latitude. In addition, approximately 35% of insects captured by the sex pheromone trap were species other than S. inferens, as determined by analyzing the nucleotide sequences of the cytochrome c oxidase 1 gene. These species were not morphologically misidentified as S. inferens.

• Korean journal of applied entomology
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• v.57 no.3
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• pp.209-220
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• 2018

Mating disruption (MD) has been widely used to effectively control Grapholita molesta in apple orchards. A simultaneous mating disruption (SMD) techniques have been developed to control both G. molesta and G. dimorpha. This study was performed to determine the practical parameters to apply the SMD technique to field conditions. To determine the application amount of SMD lures, a dispenser containing 10 mg pheromone was placed at different numbers of trees in an orchard. Application at every other tree (= one dispenser per two trees) was relatively safe to expect effective MD efficiency in both wax and polyethylene (PE) formulations. One time application at the end of March was enough to maintain a year round MD efficacy against both species. A fence treatment using food trap was applied to prevent any immigratory mated females from nearby untreated regions. To enhance the food trap by adding host-derived secondary compounds, terpinyl acetate (TA) was screened to be effective to attract females of Grapholita molesta among six compounds contained in apple fruit extracts. Among different TA concentrations, 0.05% TA treatment was the most effective to attract the adults. A mixture of TA and sugar was effective to attract and kill females and called FAKT (female attract-to-kill techniques). FAKT was treated at approximately 6 m interval at the edge of the apple orchards. The females trapped by the FAKT included mated females possessing vitellogenic oocytes. SMD supplemented with FAKT maintained the high MD efficacy and significantly suppressed leaf damage induced by the two insect pests compared to control or single SMD treatment.

• Korean journal of applied entomology
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• v.47 no.4
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• pp.435-445
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• 2008

Due to internal feeding behavior, the oriental tobacco budworm, Helicoverpa assulta ($Guen\acute{e}e$), infesting hot pepper has been regarded to be effectively controlled by targeting egg and neonate larval stages just before entering the fruits. This study aimed to develop an efficient biological control method focusing on these susceptible stages of H. assulta. An egg parasitoid wasp, Trichogramma evanescens Westwood, was confirmed to parasitize the eggs of H. assulta. A mixture of Gram-positive soil bacterium, Bacillus thuringiensis subsp. kurstaki, and Gram-negative entomopathogenic bacterium, Xenorhabdus nematophila ANU101, could effectively kill neonate larvae of H. assulta. A sex pheromone trap monitored the occurrence of field H. assulta adults. The microbial insecticide mixture was proved to give no detrimental effects on immature development and adult survival of the wasp by both feeding and contact toxicity tests. A combined treatment of egg parasitoid and microbial pesticide was applied to hot pepper fields infested by H. assulta. The mixture treatment of both biological control agents significantly decreased the fruit damage, which was comparable to the chemical insecticide treatment, though either single biological control agent did not show any significant control efficacy. This study also provides morphological and genetic characters of T. evanescens.

• Korean journal of applied entomology
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• v.56 no.3
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• pp.261-265
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• 2017

Currently, clearwing moths and peach fruit moths are considered economically important pests of jujube in Boeun, Chungbuk, Korea. However, until now, specific studies on occurrence of the major pests of jujube in Boeun area, which could be useful for pest control, have not been carried out. In this study, seasonal occurrence of three pest moths (Synanthedon bicingulata, S. haitangvora, and Carposina sasakii) in jujube orchards was monitored using sex pheromone traps. Synanthedon bicingulata and S. haitangvora were monitored from 2013 to 2015. Adults of both species were captured from May to October, with two peaks in their occurrence: mid-June and mid-September for S. bicingulata, and mid- to late-June and mid- to late-September for S. haitangvora. However, S. haitangvora occurred in lower numbers than S. bicingulata. Adults of C. sasakii were captured from 2014 to 2016. From May to October, two peaks were observed in their occurrence in mid-June and in late-August to mid-September and the second peak was lower than the first. Thus, the life histories of these pest moths of jujube should be studied in detail for an effective pest control.

• Korean journal of applied entomology
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• v.43 no.3 s.136
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• pp.201-209
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• 2004

Overwintering ecology of the peach pyralid moth, Dichocrosis punctiferalis Guenee (Lepidoptera: Pyralidae) was studied in laboratory and in a chestnut orchard in 2001/2002 winter and 2003 spring. All twenty-four female and fourteen male moths were fruit-feeding type which were emerged from the larvae collected at the same chestnut orchard in 2003 winter. Periodical thermal treatment of overwintering larvae at $25^{\circ}C$ revealed that diapause termination of the larval population started from the end of January and was completed until April 20 in southern region of Korea. Pupation of diapause-terminated larvae started from early May and reached to $100\%$ at June 3 in chestnut orchard. Days to pupation of female larvae after diapause termination were 12.5, 8.9, and 7.5 at $20^{\circ}C,\;25^{\circ}C$, and $30^{\circ}C$, respectively. Those of male larvae were similar to those of females. Pupal periods of female were 14.7, 11.8, and 9.0 days at the three temperatures. Moths of the overwintered generation emerged from May 20 to June 28, and reached to $50\%$ emergence on June 8 to 9 under emergence cage. Attraction of the male moths of overwintered generation to sex pheromone traps showed that the date of $50\%$ catches to the traps were June 17, when data from 3 southern regions of Korea were pooled.

• Korean Journal of Agricultural Science
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• v.43 no.3
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• pp.346-352
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• 2016

This study was conducted to obtain the correlation between the plant surface spray adhesion amount of pesticides and the pest control effect. The linearity of the standard curves of dinotefuran and thiodicarb was $R^2=0.9999$, and recovery was between 70% to 120% which was satisfactory for insecticide residue analyses. The pest control effect was evaluated by assessing the number of apple leafminers (Phyllonorycter ringoniella, Gracillariidae, Lepidoptera) captured by sex pheromone traps from late June to late September in 2015. For the adhesion amount, dinotefuran recovered from trap A and B, respectively were $47{\mu}g/50cm^2$ and $23{\mu}g/50cm^2$, which can be characterized as a very low adhesion amount in comparison to the average adhesion amount of $81{\mu}g/50cm^2$ in the field. In case of thiodicarb, $691{\mu}g/50cm^2$ and $71{\mu}g/50cm^2$ were recovered from trap A and B, respectively, and the average amount in the field is $325{\mu}g/50cm^2$. These results showed close correlation with the insect population captured by trap A and B. The numbers of insects captured by trap A and B between the end of July and late August were similar. After spraying thiodicarb on August 28, the number of apple leafminers captured by trap B is bigger than that of trap A. It appears that pest occurrence tended to be high at low adhesion amounts of the active ingredient. Therefore, in order to obtain an optimal control effect, it is suggested that uniform application of insecticides is critical instead of relying on the amount of insecticide applied in the field.

• Korean journal of applied entomology
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• v.60 no.4
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• pp.431-448
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• 2021

We decided the efficient application timings of organo-synthetic insecticides for controlling the first generation larvae of O. furnacalis through investigations of insect stage-specific densities, damage aspects in maize, and effects of insecticides. A waxy maize cultivar, Ilmichal, was cultivated from April 20 (sowing) to July 26 (harvest, dough stage of maize) in Suwon, 2016. The maximum and 50% cumulative catch dates of the overwintering generation adults in the sex pheromone trapping were May 29 and May 31, respectively. Most of the first generation larvae finished their occurrence till the early reproductive stage of maize. The first generation larvae fed on leaves inside the whorl leaves before tassel and stem development of maize, sequentially moved to tassel and stem, and then moved finally to stem and ear parts. In the results of insecticide applications at different dates, the 9-11 leaf stage (June 10~17) and the 6-7 leaf stage (June 3) of maize were the most efficient application timings for direct spray of Etofenprox EC to maize, and for application of Carbofuran granules onto soil surface, respectively, which resulted in suppression of tunnelling damages. The timings for the two insecticides were 12-19 days and 5 days after the adult maximum catch date, respectively. Those timings after the 50% cumulative adult catch date were advanced 2 days.