• Korean journal of applied entomology
• /
• v.49 no.3
• /
• pp.199-204
• /
• 2010

The seasonal fluctuation of the large 28-spotted lady beetle, Henosepilachna vigintioctomaculata (Motschulsky), was observed in potato fields of Gangneung region, Gangwondo Province. The effects of their leaf consumption over a 24 hour period and developmental periods by different temperatures were investigated, and then the developmental threshold (DT) and effective cumulative temperature (ET) of each stage were calculated. Various developmental stages of H. vigintioctomaculata were captured in the fields from May to September, with three peaks in late May, late June, and late August. Leaf consumption by larval stages increased with the development of instar. The 4th instar larvae consumed potato leaves much more than other stages. Egg hatchability and emergence rate of H. vigintioctomaculata were lower at $10^{\circ}C$ and $30^{\circ}C$, but higher at around $20{\sim}23^{\circ}C$. The developmental periods of each stage became shorter as temperature increased; 90 days at $10^{\circ}C$, 40 days at $20^{\circ}C$ and 25 days at $25^{\circ}C$. Base on developmental velocity to temperature, calculated DT and ET were $7.3^{\circ}C$ and 83.

• Korean journal of applied entomology
• /
• v.29 no.4
• /
• pp.238-243
• /
• 1990

These studies were conduced to investigate the effects of temperatures on development of each stage and distribution within tree and overwintering of mulberry scale, Pseudaulacaspis pentagona Tar. & Tozz. Growth ratio of each stage with different temperatures was not significant within range of optimum temperatures of growth. Developmental threshold and effective temperatures of each stage were $12.3^{\circ}C$ and 46.9 degree day in eggs, $10.8^{\circ}C$, and 183.8 degree day in first nymph, $9.8^{\circ}C$ and 188.2 degree day in second nymph, $10.3^{\circ}C$ and 383.0 degree day in gross nymphal stage, respectively. Longevity of female adults were 39.6 days in $18^{\circ}C$, 28.4 days in $22^{\circ}C$, 18.1 days in$26^{\circ}C$, and 15.7 days in$30^{\circ}C$. Average number of eggs in ovary and laid by individual female were 83.3 and 75.7, respectively. Optimum temperatures of growth were $22^{\circ}C$-$26^{\circ}C$ but all the eggs were not hatched at $35^{\circ}C$. Distribution of each stage within tree in summer was great at lower part of branch and overwintering adults was dominantly located in NE-SE followed by SE-SW, SW-NW and NW-NE. Percent mortality due to cold weather was 36.2.

• Korean journal of applied entomology
• /
• v.42 no.1
• /
• pp.53-56
• /
• 2003

Development and reproduction of the rice armyworm, Pseudaletia separata Walker, were investigated under different temperatures (13, 15, 18, 20, 25, 30, and 33$^{\circ}C$ ). It took 80.6 days to grow from egg to pre-adult at 15$^{\circ}C$, and 27.3 days at 30$^{\circ}C$ (3.0 times shorter growth period compared with that at 30$^{\circ}C$ ). The range of developmental temperature of rice armywom was 15-30$^{\circ}C$. Survival rate from hatched larva to pre-adult was the highest as 70.6% at 25$^{\circ}C$. Pre-oviposition period and the adult longevity were 4.2 and 12.3 days at 15$^{\circ}C$, and 2.9 and 8.0 days at 30$^{\circ}C$, respectively. The highest average fecundity per female was 816.6 at 25$^{\circ}C$. The net reproductive rate (R$\_$o/) and intrinsic rate of natural increase (r$\_$m/) were the highest at 25$^{\circ}C$ as 913.0 and 0.175, respectively. As a result, it was considered that optimum of temperature for P. separata growth was = 25.0$^{\circ}C$.

• Korean journal of applied entomology
• /
• v.39 no.4
• /
• pp.245-250
• /
• 2000

These studies were conducted to investigate the effect of temperature on the development and seasonal occurrence of Chrysopa pallens Ramber, a predator of aphids. Mean developmental periods of C. pallens from egg to adult emergence at four different temperatures of 17, 22, 27, and $30^{\circ}C$ were 39.5, 32.0,25.0, and 19.8 days, respectively. The longevities of adult females of C. pallens at the four temperatures were 84.7, 79.6, 77.7, and 69.8 days, respectively, whereas the total numbers of eggs laid by a female were 973, 1085, 1637, and 1735, respectively. Egg hatchability, rate of adult emergence, and sex ratio of C. pallets were slighty higher with increased temperature with 84.1~95.9%, 67.6~86.3%, and 1:1. Under three humidity conditions of 35, 55 and 75% RH, the mean developmental periods of C. pallets from egg to adult emergence at the $27^{\circ}C$ were 26, 24, and 22.9 days, respectively, while the number of eggs laid by a female were 1042.8, 1526.5, and 1640.0, respectively. Oviposition of C. pallets usually began 5~6 days after the emergence at $27^{\circ}C$. Then females laid ca. 30~40 eggs a day, reaching a peak of 80~90 eggs a day about 22~28 days after the emergence. Population fluctuation of M. persicae and A. gossypii showed the highest peak in late May through the mid-June, and the second peak appeared in early~mid-September. The adult occurrence of C. pallens by the light trap record started from mid-May, and show two peaks, in mid-late July and mid-late September in Chonbuk area.

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

• Economic and Environmental Geology
• /
• v.47 no.4
• /
• pp.335-349
• /
• 2014

The Pocheon skarn deposit, located at the northwestern part of the Precambrian Gyeonggi massif in South Korea, occurs at the contact between the Cretaceous Myeongseongsan granite and the Precambrian carbonate rocks, and is also controlled by N-S-trending shear zone. The skarn distribution and mineralogy reflects both structural and lithological controls. Three types of skarn formations based on mineral assemblages in the Pocheon skarn exist; a sodiccalcic skarn and a magnesian skarn mainly developed in the dolostone, and a calcic skarn developed in the limestone. Iron mineralization occurs in the sodic-calcic and magnesian skarn zone, locally superimposed by copper mineralization during retrograde skarn stage. The sodic-calcic skarn is composed of acmite, diopside, albite, garnet, magnetite, maghemite, anhydrite, apatite, and sphene. Retrograde alteration consists of tremolite, phlogopite, epidote, sericite, gypum, chlorite, quartz, calcite, and sulfides. Magnesian skarn mainly consists of diopside and forsterite. Pyroxene and olivine are mainly altered to tremolite, with minor phlogopite, talc, and serpentine. The calcic skarn during prograde stage mainly consists of garnet, pyroxene and wollastonite. Retrograde alteration consists of epidote, vesuvianite, amphibole, biotite, magnetite, chlorite, quartz, calcite, and sulfides. Microprobe analyses indicate that the majority of the Pocheon skarn minerals are enriched by Na-Mg composition and have high $Fe^{3+}/Fe^{2+}$, $Mg^{2+}/Fe^{2+}$, and $Al^{3+}/Fe^{2+}$ ratios. Clinopyroxene is acmitic and diopsidic composition, whereas garnet is relatively grossular-rich. Amphiboles are largely of tremolite, pargasite, and magnesian hastingsite composition. The prograde anhydrous skarn assemblages formed at about $400^{\circ}{\sim}500^{\circ}C$ in a highly oxidized environment ($fO_2=10^{-23}{\sim}10^{-26}$) under a condition of about 0.5 kbar pressure and $X(CO_2)=0.10$. With increasing fluid/rock interaction during retrograde skarn, epidote, amphibole, sulfides and calcite formed as temperature decreased to approximately $250^{\circ}{\sim}400^{\circ}C$ at $X(CO_2)=0.10$.

• Korean journal of applied entomology
• /
• v.60 no.4
• /
• pp.403-415
• /
• 2021

Seasonal development of Parthenolecanium corni was observed from 4 Jun. 2019 (nymph) - 25 Jun. 2020 (1^st Gen. nymph) in blueberry shrub in Sacheon city, Gyeongsangnam-do. To investigate their development, more than 5 twigs sprouted in 2018 were taken from the farm nearly weekly basis. The development of each scale were examined under the stereomicroscope and chemical control was conducted in the blueberry shrub with available three insecticides. The results on the development period and Centigrade Degree-Days accumulation (DDC) obtained are as follows: egg-laying period (peak): 12 -26 May 2020 (24 May)(DDC, 110.0-188.5 (173.6)); egg-hatching period (peak): 9 - 23 June 2020 (19 June)(DDC, 325.2-480.8(435.6); egg period: 26 days; nymph movement from overwintered adult to new leaves 16-25 June 2020 (DDC, 410,5-500.4); nymph movement from leaf to twig (peak) to become adult: 4-18 Feb. 2020 (8 Feb.). Eggs no. /adult (range): 956.8 ± 73.4 (13 - 3497). Size (mm) of egg, 0.29 ± 0.020(L), 0.15 ± 0.013(W); of egg-hatched nymph, 0.35 ± 0.018(L), 0.18 ± 0.007(W), 0.09 ± 0.007(eye distance); and of adult, 4.30 ± 0.893(L), 2.64 ± 0.520(W). The egg-hatched nymphs from the overwintered adult moved to the backside leaf of new shoot in which they found about 95% until leaf is falling by early February in next year. They overwintered as 2^nd instar and occurred univoltine. For the control of the 1^st instar crawler, three insecticides treated on 16 and 30 July at the registered dose for Ceroplastes japonicus. Acetamiprid 8WP showed 96.9% mortality at 21 days after 1^st treatment.

• Economic and Environmental Geology
• /
• v.17 no.4
• /
• pp.259-272
• /
• 1984

Fluid inclusion and stable isotope studies on the Sangdong tungsten skarn have led to a conclusion that the mineralizing fluids might be derived from a magma, which was inferred within 1km below the present Sangdong ore deposit. Mineral assemblages of the skarns appear to have formed under the equilibrium conditions as the fluids flow outward from a central fluid column, in which the quatz-mica occurs dominantly. A characteristic skarn showing mineralogical zonation by repeated over-prints. The quartz-mica zone at the central part of the Sangdong skarns shows the final stage of protracted fluid evolution. Thermodynamic conclusion based on simplified chemical compositions of major components may express quantitatively the conditions of the skarn formation by using diagrams.

• Korean Journal of Veterinary Research
• /
• v.37 no.1
• /
• pp.185-188
• /
• 1997

전남대학교 수의과대학에서는 조류 blue-green algae를 먹이로 하여 간질의 중간숙주인 애기물달팽이를 실험실에서 유지시켜 왔으나 조류의 배양에 어려움이 많아서 보다 간편하면서 달팽이의 번식에도 좋은 방법을 고안하고자 노력하였다. $28.5{\times}17{\times}18cm$ 크기의 유리수조에 모래를 1.5cm 높이로 깔고 10개의 꼬막껍질을 그 위에 올려놓은 다음 4리터의 증류수를 부어넣었다. 야외에서 채집한 달팽이의 난괴를 부화시켜 얻은 0.63cm 크기의 어린 달팽이 45마리를 세 그룹으로 나누어 세 개의 수조에서 $20^{\circ}C$의 온도를 유지하면서 사육하였고 먹이로 상추잎을 넣어주었다. 매주 수조바닥의 물 $2{\ell}$를 흡인하여 갈아주면서 상추잎을 바꿔넣었고, 계속해서 공기를 통과시켜 산소를 공급하였다. 이와 동일한 방법으로 실험실에서 조류로 사육하던 17대의 달팽이를 사육하여 그 성적을 비교하였던 바 야외에서 채집한 달팽이의 성장률이 실험실에 적응된 것들에 비하여 약간 떨어졌으나 생존율이나 산란율에서는 큰 차이가 인정되지 않았다. 그래서 1년이 넘도록 이 방법으로 달팽이를 사육하면서 간질의 피낭유충을 생산하고 있다. 꼬막껍질은 서서히 분해하면서 달팽이의 각을 형성하는 물질을 제공하여 생존율을 높게 한 것으로 생각된다. 그리고 수조를 햇볕이 드는 창문 가까이에 놓아두었기 때문에 조류가 자생하여 적은 양이나마 달팽이의 먹이가 되었을 것으로 보인다.

• Journal of Sericultural and Entomological Science
• /
• v.46 no.2
• /
• pp.65-71
• /
• 2004

Long term preservation experiment through refrigeration was conducted for 2 year on 300 lines of silkworm races preserved, as one method for the development of long term safe preservation technique. Experiment with 6 treatments was conducted for 680 days from July 1 st 2000 to May 1st 2002. Embryonic development was conducted to each treatment. There are no differences among treatments and races in 400 days preservation, the stage of whole embryonic development was Eul B and condition of eggs was good. In 650 days preservation experiment, differences were reveled among races and treatment, the level of whole embryonic development was Byeong A and condition of eggs was good. The order of embryonic development is European races >Tropical, Korean races >Japanese, Chinese races, thus European races showed fast embryonic development. Control(treatment A) and treatment C showed faster development than other treatments. And treatment D and F showed stable individual stage among all treatments. The test of shape characteristics and embryo which were conducted in hatching period showed 61% of high line succession possibility in average of 6 treatments. But treatment A and B showed no hatching, 3 lines of treatment C, 48 lines of treatment D, 1 line of treatment E, and 29 lines of treatment F showed slow development. And treatments D and F which showed stable embryo condition had highest possibility. The two treatments D and F showed good result among six treatments, and the preservation period of treatment D and F are 235 days and 310 days, and exposure period in $-2.5^{\circ}C$...was longer than other treatments. Numbers of hatched lines of treatment D and F are 48 and 29, and occupied 15.6% and 9.4% of all tested lines, respectively. Average hatching ratio of treatment D and F were 54.% and 71.6%, and average dead egg ratio were 12.6% and 2.4%, respectively. These results show that average ratio of hatching dead eggs in treatment D and F are higher than general line. Thus reconsideration of hatching condition on treatment D and F is needed.