• Korean journal of applied entomology
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• v.55 no.4
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• pp.421-429
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• 2016

Tenebrio molitor larvae contain large amounts of proteins, lipids and other functional materials, enabling this insect to be used as an edible food source in animal feeds and for industrialization. Although many efforts have been made to set up mass rearing systems, few studies have been conducted to establish optimal rearing conditions for the production of high quality T. molitor larvae. Herein we investigated 1) the effects of additional diets on the survival and fecundity of the insect, 2) the relationship between oviposition period and the uniformity of larval size, 3) the effects of rearing density and temperature on insect development, and 4) the storage stability of eggs and pupae at low temperatures given possible temporary production discontinuation. The addition of carrot and zucchini to the traditional wheat bran diet significantly increased the survival and fecundity rate of adult T. molitor. Of the three different oviposition sampling periods (3, 7, and 14 days) used to investigate the uniformity of the hatched larvae in each treatment, the period of 3 and 7 days provided higher uniformity than the 14 days oviposition period. Larval development was faster at $30^{\circ}C$ than at 20, 25, and $35^{\circ}C$. Interestingly, oviposition rates were highest at $20^{\circ}C$ but showed much slower larval development and lower uniformity at $30^{\circ}C$. Regarding the effect of larval rearing densities (1, 10, 20, 30, 40, and 50 larvae per 90 mm diam. dish), larval weight was significantly reduced at higher rearing densities, but larval longevity and length were not influenced by rearing density. The 30 larvae/dish is suggested to be a reasonable density to be applied to mass production systems. When kept at $4^{\circ}C$, T. molitor eggs showed a significant reduction in hatching rate; however, when stored under the same conditions, pupae emergence rates remained high until 10 weeks, suggesting that storage at low temperatures is more suitable for the pupal stage than the egg stage. Our findings suggest that an increase in T. molitor adult survival and fecundity rates and a uniformity of hatched larval development can be achieved with the following recommendations: a combination diet (including wheat bran), a 7-day oviposition period; a larvae-rearing temperature of $30^{\circ}C$, a rearing density of 30 larvae/dish, and the storage of pupal stages at low temperatures in the case of rearing discontinuation. This study serves as a strong foundation for the successful mass production of high quality T. molitor larvae.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.694-700
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• 2018

To investigate the effect of heavy metals (Cu, Cd, Hg, Pb, Zn) on mosquito Culex pipiens, 50% lethal concentration ($LC_{50}$) concentration, total lipid content, lipid content composition, and total protein content were measured. The results showed that the Hg $LC_{50}$ was $0.45mg\;kg^{-1}$ and the Hg toxicity was higher than the other metals. The results also showed that cadmium (Cd) significantly retarded the growth of mosquito larvae among the tested heavy metals. Six types of lipid bands were isolated from mosquito samples exposed to heavy metals, and five of them were identified (phospholipid, cholesterol, fatty acid, triglyceride, and cholesterol ester). The total lipid content of all treatments decreased compared to the control. In addition, the protein content of the control group ($0.51mg\;ind.^{-1}$) was higher than that of the treated group, and the protein content of the larvae treated with Hg and Cd was very low. In conclusion, heavy metals not only lower the survival rate of mosquitoes, but also affect the protein content and lipids in the mosquito's body, thereby causing growth inhibition. These results indicate that heavy metal contamination will affect the size of mosquito population by inhibiting the survival and growth of mosquitoes, and it is expected that it can be used to measure the degree of contamination using mosquito through subsequent studies.

• Korean journal of applied entomology
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• v.63 no.1
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• pp.13-23
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• 2024

Vespa velutina nigrithorax du Buysson, 1905 is the invaded species in Korea since 2003. Since its importance as the honey bee pest, beekeepers use insecticides to kill the adult and immature hornets. However, its legality and effectiveness has not been confirmed. This study investigated the susceptibility of insecticides commonly used to control hornets by beekeepers in Korea. Eight insecticides were tested on adult worker and larvae by topical or oral treatment. Adults showed more than 70% mortalities from Clothianidin, Dinotefuran, and Carbosulfan treatment within 30 minutes. Bifenthrin and Cartap hydrochloride showed relatively low toxicity. The median lethal dose (LD₅₀) for Clothianidin, Dinotefuran, and Carbosulfan was 0.29, 0.65, and 2.21 ㎍/bee, respectively. In larval feeding test where 5^th instar larvae were fed 3 times every 24 hours, the mortality began after second treatments. After 3rd treatments (72 h), all insecticides showed mortality more than 70%. The LD₅₀ values of Clothianidin, Dinotefuran, and Carbosulfan to V. velutina were approximately 10 to 100 times higher than those to honey bee, Apis mellifera. This study provides the basic information of those chemical toxicities to Vespa hornet and honey bees.

• Korean journal of applied entomology
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• v.19 no.1 s.42
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• pp.57-65
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• 1980

The oriental tobacco budmoth, Heliothis assulta Guenee were reared under various temperatures; $20^{\circ}C,\;25^{\circ}C,\;30^{\circ}C$ and the control effects of Thuricide $HP^{(R)}$ were examined. The results obtained were as fellows: 1. The adult longevity of oriental tobacco budmoth was 11.35 days, and 3.00 days for preovipositional period, 4.75 days for ovipositional Period, and 3.50 days for postovipositional period. 2. The total number of eggs laid by a female were 307 at $20^{\circ}C$, 413 at $25^{\circ}C$ and 189 at $30^{\circ}C$. The number of eggs per female per day were 64.05 in average. 3. The average egg Periods were 7.71 days at $20^{\circ}C$, 4.12 days at $25^{\circ}C$ and 3.58 days at $30^{\circ}C$ and the hatchiabilities were $71.25\%,\;78.49\%\;and\;81.05\%$ at the respective incubation temperatures. 4. The larval developmental periods were 43.51 days at $20^{\circ}C$, 21.79 days at $25^{\circ}C$ and 18.05 days at $25^{\circ}C$ and the mortalities were $80.70\%,\;95.93\%$ and $87.01\%$ at the respective temperatures. 5. The pupal developmental periods were 24.22 days at $20^{\circ}C$, 12.36 days at $25^{\circ}C$ and 11.50 days at $30^{\circ}C$ and the mortalities at the respective temperatures were $18.18\%,\;42.11\%\;and\;40.00\%$. 6. The calculated threshold temperatures for the development were $11.61^{\circ}C$ for the eggs, $11.96^{\circ}C$ for the larvae, and $10.06^{\circ}C$ for the pupae. The estimated total effective temperatures were 60.41 day degrees for e eggs, 319.35 day degrees for the larvae, 222.66 day degrees for the pupae, and overall total effective temperatures, however, would be ranged 640-660 day degrees if the reproductive period of the adult was considered. 7. The relationship between the overall developmental periods and the rearing temperature could be Y=-4.272X+155.39 (r=0.9105), where Y; number of days required to complete the life cycle, X; treated temperatures. 8. The control effects of Thuricide $HP^{(R)}$ were $73.43\%$ for spray and $58.22\%$ for bait applications.

• The Korean Journal of Pesticide Science
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• v.14 no.1
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• pp.54-64
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• 2010

Effects of thirteen essential oils (anise oil, clove oil, marigold, mustard oil, neem oil, quassia, quilaja, rosemary oil, rotenone, tea tree extract, thyme oil, wintergreen oil, and yucca) and caffeine on typical industrial insect, silkworm (Bombyx mori) and two entomopathogenic nematodes, Steinernema carpocapsae GSN-1 strain (Sc) and Heterorhabditis sp. Gyeongsan strain (Hg) were investigated in the laboratory. When 1,000 ppm of each essential oils was treated, neem oil showed the highest insecticidal activity against silkworm. Mortality of silkworm fed on neem oil treated mulberry leaf was 55.3 and 100% 5 and 10 days after treatment, respectively. The silkworm fed on neem oil treated mulberry leaf did not make cocoon and pupa. Weight of cocoon and pupa was low in rotenone treatment showing 0.27 g and 1.01 g, respectively. Mustard oil had the highest nematicidal activity against entomopathogenic nematodes. 20 ppm of mustard oil resulted in 69.0% and 100% mortality of Sc and Hg 3 days after treatment, but 4% and 36% at 5 ppm in X-plate, respectively. Mortality of baited Galleria mellonella larva by Sc was not different from control at the concentration of 100 ppm of mustard oil while 30% lower in Hg in sand barrier. Mean numbers of established infective juveniles of Hg in Galleria larva were lower than Sc in sand barrier. Survival rate of Sc was similar to control at the concentration of <200 ppm of mustard oil in sand barrier.

• Applied Biological Chemistry
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• v.38 no.5
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• pp.435-439
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• 1995

Some characteristics and pathogenicity of Hyphantria cunea nuclear polyhedrosis virus (HcNPV), a potential microbial pesticide was studied. H. cunea NPV replicated in the nucleus of S. frugiperda cells cultured in the TNMFH medium. In case of virus infected cell, prepolyhedra formation was observed at 24hrs post-infection. At 48 hrs post-infection, Most of the infected cell contained many mature polyhedra which were released into culture media 72 hrs post-infection, with the cells grown in suspension culture, pH of the culture medium increased during the virus replication: the pH of fresh medium was 6.35 and rose to 6.77 within 120 hrs. Polyhedra formed a band in linear density gradient of sucrose by centrifugation, which co-sedimented with $50{\sim}55%$ sucrose. The shape of the purified polyhedra was mostly tetragonal hexahedron and its size was about $2.5{\mu}m$. Electron microscopy and phase contrast microscopy showed that many bundled nucleocapsids were occluded in mature polyhedra at 48 hrs post infection. H. cunea larvae infected with NPV showed a higher motality in the second and third instar than in the fourth instar. Death rate of H. cunea larvae in the second and third instar fed with leaves coated with $1.5{\times}10^{9}{\sim}l.5{\times}10^{7}PIBs/ml$ reached more than 90%.

• Korean journal of applied entomology
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• v.30 no.2
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• pp.130-130
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• 1991

현미를 사료로하여 네가지 정온도조정에서(25, 28, 34, 36$^{circ}C$ $pm$0.5$^{\circ}C$, RH 70%)에서 거짓쌀도둑(Tribilium castaneum Herbst)의 각 충태별 평균발육기간($\pm$SE)을 산출하였으며, 이를 기초로하여 발육임계온도를 추정하였다. 난의 평균발육기간은 각 온도에서 7.6$\pm$0.25, 4.8$\pm$0.10, 3.0$\pm$0.03, 2.5$\pm$0.09일, 유충에서 각각 53.3$\pm$1.49, 33.4$\pm$0.57, 30.6$\pm$0.70, 31.0$\pm$1.18일, 용에서 각각 12.1$\pm$0.17, 7.8$\pm$0.09, 5.0$\pm$0.07일로 산출되었으며, 난에서 성충우화시기까지의 전발육기간은 각각72.3$\pm$1.67, 46.0$\pm$0.05, 39.4$\pm$0.64, 38.7$\pm$1.15일로 산출되었다. 난과 용의 발육기간은 밀과 옥수수같은 다른 식이조건에서와 유사하였으나, 섭식을 하는 유충기의 발육은 밀보다 현미에서 상대적으로 지체되는 현상을 보였다. 한편 현미를 섭취했을 경우, 밀을 섭취했을 때 보다 발육중 치사율이 높아 밀에 비해 현미가 저급의 식물임을 보여주었다. 거짓쌀도둑 난, 유충 용 및 전발육기간의 저온발육임게온도는 각 충태 공히 20.0$^{\circ}C$로 산출되었으며, 유충과 전발육기간의 고온발육임계온도는 각각 40.2$^{\circ}C$와 41.9$^{\circ}C$로 추정되었다. 영기수는 온도에 상관없이 최빈치 7회를 나타냈지만, 온도의 상승에 따라 7회 이상 탈피하는 비율이 높아지는 경향을 보였다. 성비는 온도와 무관한 것으로 나타났다.

• The Korean Journal of Pesticide Science
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• v.10 no.2
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• pp.107-116
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• 2006

Korean entomopathogenic nematode strain were evaluated against white grubs, Popillia quadriguttata, Ectinohoplia rufipes and Phyllopertha diversa in laboratory. In addition we examined the efficacy of entomopatogenic nematode, Heterorhabditis sp. KCTC 0991BP strain against white grubs in Seaside Golf Club in Gimpo, Gyeonggii and persistence of entomopatogenic nematode in fairway of Anyang Benest Golf Club in Gunpo, Gyeonggii. In laboratory Heterorhabditis bacteriophora Hamyang strain showed 95% mortality against Popillia quadriguttata. H. bacteriophora Hamyang strain and Heterorhabditis sp. KCTC 0991BP induced 80% mortality against 3rd instar of Ectinohoplia rufipes. However, the letter showed only 60% mortality against Phyllopertha diversa. White grub density was reduced to 39% by the application of Heterorhabditis sp. KCTC 0991BP at the rate of $2.24{\times}10^9$ infective juveniles $ha^{-1}$ compared with control in Seaside Golf Club. Heterorhabditis sp. KCTC 0991BP persisted for two months at $5{\sim}10$ cm soil depth but not persisted at $0{\sim}5$ cm soil depth for the same periods when applied at the rate of $2.47{\times}10^9$ infective juveniles $ha^{-1}$.

• The Korean Journal of Pesticide Science
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• v.20 no.1
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• pp.47-55
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• 2016

The purpose of this study was to control root-knot nematode, Meloidogyne incognita on pumpkin seedling with 10%, 20% coffee ground compost and 1% plant velvet bean powder (plain skin bean, leopard skin bean, hole plant, bean pod). Among the root-knot nematode insecticide treatments, the velvet bean plant powder was the highest mortality rate with 83.2% in greenhouse condition. In addition, the root-knot nematode second juvenile mortality significantly increased with the lapse of processing time for each concentration of leopard skin velvet bean extract in vivo. After 24 hours, the mortality rate of root-knot nematode showed the highest at 1.2% and 2.4% of leopard skin velvet bean extract. The growth promoting effect of seedlings pumpkin, 20% of coffee ground compost treatments inhibited the growth of pumpkin seedlings and 1% the tiger pattern velvet beans powder was the most to promote the growth of pumpkin seedlings. However, the results indicated that the organic materials of velvet beans and coffee ground compost are expected to be able to effectively control the root-knot nematode and further studies will be needed for the concentration and application methods.

• Asian Journal of Turfgrass Science
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• v.19 no.1
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• pp.39-46
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• 2005

The 21 strains of Korean entomopathogenic nematodes, {Heterorhabditis bacteriophora Hamyang strain(HbH), Heterorhabditis sp. 202, 205, 217, Heterorhabdiris sp. KCTC 0991BP strain, Steinernema carpocapsae Pocheon(ScP), S. longicaudum Gonaju, S. longicaudum Nonsan, Steinernema sp. 7,24, 52, 55, 60, 64, 206, 207, 209, 210, 219, and 227 strain} were evaluated for the control of a turfgrass insect pest, Exomala orientalis. Heterorhabditis spp. showed higher pathogenicity than Steinernema spp. against 3rd instar larvae of E. orientalis with $55\%$ mortality by Heterorhabditis sp. 202 strain and $50\%$ by HbH and Heterorhabditis sp.205 strain at the rate of 200 infective juveniles per larva 14 days later after treatment. The number of infective juveniles of Korean entomopathogenic nematodes in 3rd instar larvae of E. orientalis was higher in Heterorhabditis spp. than in Steinernema spp.. In general, numbers of produced infective juveniles of three species were much higher, i.e., Heterorhabditis sp.202 strain produced 273,064 infective juveniles, S. carpocapsae Pocheon strain 273,043, and Heterorhabditis sp. 217 strain 248,887, respectively.