• Journal of Sericultural and Entomological Science
• /
• v.33 no.1
• /
• pp.32-36
• /
• 1991

The study has been carried out to acquire some basic informations about Bacillus thuringiensis for developing the microbial pesticide. Three strains of Bacillus thuringiensis var. Kurstaki, dendrolimus and aizawai, were used in the experiments as follows. Growth characteristics of each strain were examined and parasporal protein crystals were isolated from the mixtures of spores and protein crystals by the new method of centrifugation in two-layer cushion of Renograffin using a fixed angle rotor. The results are as follows. 1. No difference was shown in growth characterestics among three strains of B. thuringiensis. In growth curves, all strains reached to exponential phase by 2 hr and stationary phase by 7-8 hr after inoculation. 2. The pH of the culture media during exponential growth stage decreased about 1.4 of a pH unit at the beginning of sporulation, but recovered during the early stage of sporulation and then remained nearly constant during the later stage. 3. As 10$m\ell$ sample was applied to two-layer cushion of Renograffin and then centrifuged for 1hr at 27,000g a fixed angle rotor, the purity and recovery ratio was 99.9% and 5.8%, respectively. It has been shown that the new method for the isolation of parasporal protein crystals was more efficient than any from the estabilished methods.

• Korean journal of applied entomology
• /
• v.50 no.2
• /
• pp.131-139
• /
• 2011

This study investigated the adverse effects of sound treatment on physiological processes of the American leafminer, Liriomyza trifolii, during several developmental stages. Larval feeding activity was analyzed by measuring feeding tunnel length. It was significantly suppressed by sound treatment (5,000 Hz, 95 dB). Sound treatment delayed the pupal period at 315 - 5,000 Hz and prevented adult emergence at 1,000 - 5,000 Hz. Female oviposition was also inhibited by the stress sound treatments. However, phototactic adult movement was not affected by sound treatment. Pupae treated with 5,000 Hz showed marked changes in protein patterns analyzed by two dimensional electrophoresis. MALDI-TOF analysis of specific protein spots indicated that trafficking protein particle complex I, triosephosphate isomerase, hypothetical protein TcasGA2_TC013388, polycystin-2, paraneoplastic neuronal antigen MA1, and tropomyosin I (isoform M) were predicted in the control insects and disappeared in the insects treated with sound. By contrast, DOCK9, cytoskeletal keratin II, and F0F1-ATP synthase beta subunit were predicted only in the sound-treated insects. Furthermore, stress sound significantly increased the susceptibility of L. trifolii to insecticides. These results suggest that physiological processes of L. trifolii are altered by sound stress, which may be exploited to develop a novel physical control tactic against L. trifolii.

• Korean journal of applied entomology
• /
• v.50 no.1
• /
• pp.39-46
• /
• 2011

This study analyzed effects of different sound treatments in frequencies and intensities on digestion and immune physiological processes of the beet armyworm, Spodoptera exigua larvae. Without effect on egg hatch, sound treatments with 100-5,000 Hz at 95 dB suppressed feeding behavior and inhibited a digestive enzyme activity. In addition, two dimensional electrophoresis of midgut luminal proteins indicated a marked difference of the sound-treated larvae. In response to 5,000 Hz at 95 dB, larvae showed a significant decrease in hemocyte nodule formation against fungal challenge along with significant suppression in phospholipase $A_2$ activity in hemocyte and plasma. With increase of sound frequencies, the treated larvae showed an enhanced susceptibility to insecticides. Such sound frequency effect was significantly modulated with different sound intensities. These results suggest that sound treatment may give adverse stress to physiological processes of S. exigua larvae and may be applied to a nonchemical insect pest control.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.19 no.2
• /
• pp.81-85
• /
• 2013

The stored-product insects have been a serious problem during the entire process of distribution on the food industry. Especially, the Indian meal moth (Plodia interpunctella) is one of stored-product insects which causes harm through penetrating into the food packaging. The objective of this study was to develop the anti-insect packaging material with fennel (Foeniculum vulgare) oil (FO). The FO has been selected for insecticidal substance against P. interpunctella, which was tested by fumigant toxicity assay. An anti-insect sachet was prepared by FO and filterpaper placed in a small paper bag. Repellent test was performed to evaluate the repellent activity of anti-insect sachet. In addition, the controlled release of FO from the anti-insect sachet was determined at $28^{\circ}C$ by gas chromatography (GC). It was demonstrated that FO was an effective substance against P. interpunctella. The mortality of FO was 56% at 800 mg/0.5 L in 120 h. In repellent test, the FO sachet showed effective repellency against P. interpunctella. The developed anti-insect sachet could be a promising source for insect repellent materials in food packaging.

• Research in Plant Disease
• /
• v.18 no.3
• /
• pp.245-249
• /
• 2012

The small brown planthopper (Laodelphax striatellus) is one of the most important rice pests in Republic of Korea because it damages rice plants not only by sap-sucking but also by transmitting Rice stripe virus (RSV). Outbreaks of RSV are closely related to outbreaks of the small brown planthopper (SBPH). Therefore, it is very important to control SBPH for the management of RSV. Mass-migrating SBPH collected by aerial net traps in June 2011 at Taeanup, Geunheungmyon and Gonammyon in Taeangun were examined for virus carrier status and effects of the pesticide, 'Myungtaja', on the control of RSV. Among 1,217 SBPH trapped, about 7.7% were detected as RSV positive and 4.4% were positive for Rice black streak dwarf virus (RBSDV) by RT-PCR. After the mass migration, pesticide 'Myungtaja' was sprayed once or twice on rice fields and compared to untreated fields. The incidence of RSV was not affected by the frequency of spraying 'Myungtaja' but was influenced by the time of pesticide treatment. Myungtaja' treatment within 5-7 days after mass migration resulted in the most efficient RSV control, resulting in RSV incidence decreased by 87.6% compared to the control. Therefore, we conclude that pesticide spraying for RSV control was most effective when it was done within 5-7 days after mass migration.

• Journal of Applied Biological Chemistry
• /
• v.60 no.2
• /
• pp.137-140
• /
• 2017

Agricultural pests, diamondback moth (Plutella xylostella), green peach aphid (Myzus persicae) and two-spotted spider mite (Teyranychus urticae), are becoming major pests in human dwellings in a variety of ways across the world. For management of these pests, the essential oils of Coriandrum sativum and Cinnamomum cassia prepared by steam distillation, hexane extraction and supercritical extraction methods were evaluated for the insecticidal effects. Using the contact bioassay, the $LD_{50}$ value of C. sativum oil by steam distillation extraction method was $30.59{\mu}g/cm^2$ against M. persicae adults. The $LD_{50}$ values of C. cassia oils prepared by steam distillation and hexane extraction methods were 5.96 and $4.64{\mu}g/cm^2$, respectively, against T. urticae adults, and $LD_{50}$ value of the essential oil by supercritical extraction method was $6.50{\mu}g/cm^2$ against M. persicae adults. This study showed that C. sativum and C. cassia oils could be an effective natural acaricide and insecticide against agricultural pests.

• The Korean Journal of Pesticide Science
• /
• v.19 no.4
• /
• pp.440-449
• /
• 2015

Pine wood nematode (PWN), Bursaphelenchus xylophilus is one of the most serious pests of pine tree. Trunk injection of some nematicides in tree is well known as an effective control method. However there are some limitating factors which hindering the efficacy of trunk injection in field or potted tree. In this study we suggested easy and useful alternative screening methods of nematicides against PWN. Reproduction of PWN was influenced by tree twig moisture (high reproduction in high moisture trig) and paraffin coating was 78.6% reduced moisture loss in tested twig. There were no reproduction different in up and down site from infection site of twig at 1 month after inoculation of PWN and also distance (5 and 10 cm) from inoculation site of PWN did not influence the reproduction of PWN. Numbers of reproduced PWN were higher with decreasing diameter of twig. Numbers of reproduced PWN were similar to P. thunbergii and P. densiflora. However reproduction was increased depending on high inoculation density and longer propagation period. When inoculation of PWN on cut twig injected with emamectin benzoate 2.15% EC and morantel tartrate 8% SL in trunk of Pinus thunbergii in the field, PWN number were significantly reduced than untreated control. We suggest this screening method for PWN control agents.

• The Korean Journal of Pesticide Science
• /
• v.20 no.1
• /
• pp.56-65
• /
• 2016

Pine wood nematode, Bursaphlenchus xylophilus is a fatal damaging pest, infecting pinewood trees and is one of the serious forest pest in Korea. Trunk injection is one of the most effective method to protect the live pine trees from nematode infection. The aim of this research was to reveal the efficacy of the nematicidal materials from 46 Kyrgyzstan, 88 Vietnam plant materials and 21 active materials (${\alpha}$-terpinene, ${\alpha}$-pinene, ${\beta}$-thujaplicin, cinnamaldehyde, eugenol, emodin, geraniol, limonone, methyl palmitate, matrine, myrcene, methyl gallate, nicotine, quassin, resveratrol, rotenone, thymol, thujaplicin, terthiophene, tuberstemonine, ${\gamma}$-terpinene) isolated from plants for using as trunk injection agents. Eclipta prostrata extract was highly effective against pine wood nematode in plant extracts and terthiophene has the best nematicidal activity from active materials isolated from plants. Foliar spray of terthiophene on Japanese black pine (Pinus thunbergii) tree reduced proliferation of inoculated pine wood nematode at 22 days after treatment, however no efficacy was found over 22 days. Eclipta prostrata extract and terthiophene can be used as nematicide for further nematicidal efficacy test against any other plant parasitic nematodes and trunk injection efficacy against pine wood nematode.

• Korean journal of applied entomology
• /
• v.56 no.3
• /
• pp.261-265
• /
• 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
• /
• v.56 no.3
• /
• pp.267-273
• /
• 2017

To protect plants from damage caused by Panonychus citri (McGregor), practical methods for the use banker plants have been developed to provide a habitat and augment natural enemies of several agricultural pests. The average population density of predatory mites on an Oxalis corniculata (creeping sorrel) sod culture was significantly higher (three times) than that on normal sod culture. Furthemore, the average population density of spider mites on creeping sorrel sod culture was significantly lower (3.7 times) than when weed control was practiced. Average consumption of the eggs and females of Tetranychina harti (Ewing) by Neoseiulus californicus (McGregor) females was approximately 1.96 eggs and 1.93 females per day, respectively. Phytoseiulus persimilis AthiasHenriot females never consumed T. harti. However, total development time of T. harti from egg to adult on O. corniculata was 17.4 days, and hatchability and survival rate were 77.5% and 84.8%, respectively.