• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.29 no.1
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• pp.28-41
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• 2024

The carbon balance serves as a valuable indicator of a plant's physiological status under diverse environmental conditions. We investigated the photosynthetic and respiratory responses of the Asian surfgrass Phyllospadix iwatensis along the northeast coast of the Korean peninsula in response to changing water temperature (ranging from 5℃ to 30℃) to estimate the seasonal whole-plant carbon balance through a series of incubation experiments. The maximum gross photosynthetic rate (P_max) showed a significant difference among the temperature treatments, while there was no significant difference in photosynthetic efficiency (α). The maximum gross photosynthetic rate of P. iwatensis reached its peaks at 20℃ treatment (101.65 μmol O₂ g^-1 DW h^-1) but decreased rapidly at 30℃. The saturation irradiance (I_k), compensation irradiance (I_c), and respiration rate (R) of P. iwatensis exhibited significant differences among the temperature treatments. The saturation irradiance increased up to 20-25℃ (121.59-124.50 μmol photons m^-2 s^-1) and sharply decreased at 30℃. The compensation irradiance and respiration rate increased steadily with rising water temperature. The ratio of P_max to R (P_max:R ratio) was the highest at 5℃ but dramatically decreased at 30℃. The whole-plant carbon balance, calculated based on photosynthetic parameters, respiration rates, and biomass, exhibited distinct seasonal variation, increasing during winter and spring and decreasing during summer and fall, which is consistent with the highest in situ growth in spring and severely limited growth at the highest water temperature conditions. Phyllospadix iwatensis displayed a negative carbon balance during late summer, fall, and winter, but demonstrated a positive carbon balance during spring and early summer. Our findings suggest that the rising seawater temperatures associated with climate change may lead to significant alterations in the seagrass ecosystem functioning along the rocky shores of the Korean east coast.

• Korean journal of applied entomology
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• v.42 no.1
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• pp.53-56
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• 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
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• v.37 no.2
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• pp.193-198
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• 1998

Experiments were conducted to investigate the population fluctuation, developmental periods, fecundity, hatching rate and demage of Citrus red mite (Panonychus citri M.) on Yuzu trees (citrus junos T.) from 1996 to 1997. Citrus red mite occurred from May to November and made two peaks. The first peak was in July to August and the secondary peak was in October. Density of the second peak was higher (9.5 miteslleaf) than that of the first peak. In the constitution rate of each developmental stage of citrus red mite on Yuzu leaves, egg stage occupied 85%. At the four constant temperature (15, 20, 25, 30 + 1$^{\circ}$C, RH 60 + lo%, 14L- IOD) conditions, the developmental period from egg to adult was 41 .l, 15.5, 11.0 and 9.4 days ; Mean longevity of adult was 23.3, 8.3, 6.3, and 6.1 days; Mean number of egg laid per female per day was 1.6, 3.2, 4.5, 4.0 eggs; Mean hatching rate was 66.6, 85.7, 90.7 and 94.7% at above temperature, respectively. When sprayed acaricide at different density of Citrus red mite, the growth of young Yuzu tree were better at low density. Defoliation rate during winter was 13.5, 20.6, 53.1, 72.6% at 4 control density 1 , 3, 6 mites per leaf and uncontrolled (10 ( ). When every time spray acaricide under 3 mites per leaf, defoliation rate during winter suppressed above 50% compare to uncontrol 72.6%.

• Korean journal of applied entomology
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• v.53 no.4
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• pp.449-456
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• 2014

Life table analysis and temperature-dependent development experiments were conducted to understand the biological characteristics of the cabbage aphid, Brevicoryne brassicae (Linnaeus) on detached Tah Tsai Chinese cabbage (Brassica campestris var. narinosa) leaves at seven constant temperatures (15, 18, 21, 24, 27, 30 and $33{\pm}1^{\circ}C$; $65{\pm}5%$ RH; 16L:8D). Mortality was lowest at $24^{\circ}C$ with 18% and 0% at $1^{st}{\sim}2^{nd}$ and $3^{rd}{\sim}4^{th}$ nymphal stages, respectively. The developmental period of $1^{st}{\sim}2^{nd}$ nymphal stage was 8.4 days at $18^{\circ}C$, and it decreased with increasing temperature. The developmental period of the $3^{rd}{\sim}4^{th}$ nymphal stage was 6.7 days at $18^{\circ}C$. The lower threshold temperature calculated using a linear model was $7.8^{\circ}C$, and the effective accumulative temperature was 120.1DD. Adult longevity was 14.9 days at $21^{\circ}C$, and total fecundity was observed 58.5 at $24^{\circ}C$. According to the life table, the net reproduction rate was 47.5 at $24^{\circ}C$, and the intrinsic rate of increase and the finite rate of increase were 0.36 and 1.43, respectively, at $27^{\circ}C$. The doubling time was 1.95d at $27^{\circ}C$, and mean generation time was 7.43d at $30^{\circ}C$.

• Korean journal of applied entomology
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• v.44 no.4 s.141
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• pp.293-298
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• 2005

The embryonic and postembryonic developments of Pierodorus hybneri Linnaeus were observed in 5 different rearing cages such as A (Cylindrical, 10 cm in diameter, height of 4 cm), B (Cylindrical, 14.5 cm in diameter, height of 2.8 cm), C (Rectangle, 6.5 by 6.5 cm in $length{\times}breadth$, height of 10 cm), D (Cylindrical, 9 cm in bottom diameter, 11.5 cm in upper diameter, height of 10.8 cm) and E (Cylindrical, 15 cm in diameter, height of 7.5 cm) containing soybean and peanut seeds as feeding food, and sponge-water container under laboratory condition of $24^{\circ}C$ and 16L:8D. Egg duration was 6 days regardless of rearing cages. Hatchability ranged from 63 to 80% with the highest in B (14.5 cm in diameter, 2.8 cm in height) rearing cage. Instar duration was longer from 5 days in 1st instar to about 11 days in 5th instar. Nymphal duration showed 35 to 36 days with'3ut significant difference in rearing cages. Percent emergence was in range from 65 to 82% with the highest in B rearing cage. Adult longevity was 35 to 83 days for male, and 32 to 79 days for female, and was the longest in B rearing cage. Total number of eggs laid by female adult was in range from 38 to 86 with significant difference in rearing cages, and was the most in B rearing cage. Accordingly, the reproductive rate of P. hybneri for 1 generation was within 17 to 56 times, and was the highest in B rearing cage. Therefore, it could be concluded that B cage is most suitable for stable rearing of P. hybneri under laboratory condition.

• Korean journal of applied entomology
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• v.22 no.4 s.57
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• pp.237-243
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• 1983

A biological study was done on primary parasites and hyperparasites of cow-pea aphid, Aphis craccivora Koch, collected from Mt. Gyeryong and Daejeon area during the period from April to September 1983 was. The results of mummification of primary parasites, host selectivity between primary parasites and hyperparasites and ratio of mummification, no. of ar chegonia and longevity of important species were obtained as follows; Eight species of Aphidiidae were identified and listed and four of them, Binodoxys nearactaphidis Mackauer, Lipolexis scutellaris Mackauer, Lysiphlebus salicaphis(Fitch)and Trioxys hokkaidensis Takada found for the first time in Korea. Among the 509 mummies collected in the field, adult Aphidiid and adult hyperparasites were $44.8\%,\;and\;43.8\%$, respectively. Lysiphlebus ambiguus, Lysiphlebus salicaphis, Lysiphlebia japonica and Lipolexis scutellaris were a few of important species attacking cow-pea aphid and the rate of their occurrences were $31.6\%,\;18.8\%,\;16.7\%\;and\;11.4\%$, respectively. All the hyperparasites collected from cow-pea aphid were recorded for the first time in Korea; those were Lygocerus testaceimonus Kieffer, Protaphelinus nikolskajae (Jasnosh), Eucoila sp., Gastranscistrus sp., Ardilea convexa(Walker), Asaphes vulgaris Walker. Among the collected hyperparasites, Eucoila sp., A. vulgaris and A. Convexa were dominant species and their occurence rate was $39.9\%,\;34.1\%\;and\;19.7\%$, respectively. As a results of analysis on parasite-hyperparasite interrelationship in cow-pea aphid, Lipolexis scutellaris was attacked from 3 out of 6 hyperparasites and the others was attacked from almost all the hyperparasites. Lysiphlebus ambiguus was higher than Lysiphlebia japonica in the ability of parasitism. There was no difference between Lysiphlebus ambiguus(272) and Lysiphlebia japonica(279) in number of archegonia, but L. ambiguus$(66.9\%)$ was higher than L. japonica$(43.0\%)$ in the rate of mummification to archegonia. The longevity of Aphidiidae and hyperparasites was investigated by feeding honey. The results showed that hyperparasites had lived 15.8 to 21. 5 days, while Aphiidiidae lived only 2 to 3 days.

• Korean journal of applied entomology
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• v.57 no.4
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• pp.261-269
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• 2018

The cowpea aphid Aphis craccivora Koch (Hemiptera: Aphididae) is a polyphagous species with a worldwide distribution. We investigated the temperature effects on development periods of nymphs, and the longevity and fecundity of apterous female of A. craccivora. The study was conducted at six constant temperatures of 10.0, 15.0, 20.0, 25, 30.0, and $32.5^{\circ}C$. A. craccivora developed successfully from nymph to adult stage at all temperatures subjected. The developmental rate of A. craccivora increased as temperature increased. The lower developmental threshold (LT) and thermal constant (K) of A. craccivora nymph stage were estimated by linear regression as $5.3^{\circ}C$ and 128.4 degree-days (DD), respectively. Lower and higher threshold temperatures (TL, TH and TH-TL, respectively) were calculated by the Sharpe_Schoolfield_Ikemoto (SSI) model as $17.0^{\circ}C$, $34.6^{\circ}C$ and $17.5^{\circ}C$. Developmental completion of nymph stages was described using a three-parameter Weibull function. Life table parameters were estimated. The intrinsic rate of increase was highest at $25^{\circ}C$, while the net reproductive rate was highest at $20^{\circ}C$. Biological characteristics of A. craccivora populations from different geographic areas were discussed.

• Korean journal of applied entomology
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• v.27 no.2
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• pp.103-110
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• 1988

The behavior and circadian rhythm of emergence, copulation and oviposition in the Oriental tobacco budworm (Heliothis assulta Guenee) were studied to obtain the following results. More than three quarters of adults emerged within 3 hours after the light-off. It took about 33 min for an adult to expand and tan its wings after emergence. Adult male showed a sequential pattern of mating behavior, such as antennal movement, wing elevation and vibration, exten¬sion of hairpencils, and tapping of female ovipositor leading to a copulation. However, adult female revealed a rather simple behavior, such as protraction and retraction of her terminal abdomen and vibration of wings. All of the mating took place during the early part of the scotophase, with the peak from 1 hr to 2 hrs after the light-off. But the mating peak in virgin females tended to advance with age. Adult females showed the highest rate of mating among 24 hr-olds and the rate declined with age. The rate of first matings in males gave a very similar pattern to that of females. The duration of copulation was $77\pm$14min. Oviposition occurred throughout the entire scotophase, with the peak during the first 2 hrs. The most nu¬mber of eggs deposited daily was seen on the 3rd day after the mating. Mating rate, number of eggs laid and longevity we~e compared under different sex ratio. Unmated adults lived longer than mated adults.

• Korean journal of applied entomology
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• v.42 no.3
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• pp.211-216
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• 2003

Development and reproduction of Dichromothrips smithi were investigated under different temperatures, Durations of the development from egg to pre-adult of D. smithi were measured under 11 temperature ranges and it was 44.0 days at 13$^{\circ}C$ and 8.7 days at 32$^{\circ}C$. Developmental zero point and total effective temperature for the development of egg and larva, prepupa, pupa and for the complete development (egg to emergence) were 9.4, 8.9, 10.5, 10.8 and 9.5$^{\circ}C$, and 46.1, 90.1, 23.9, 41.2 and 204.4 degree days, respectively. The adult longevity was 28.3 days at 15 C and 14.3 days at 30$^{\circ}C$. The highest average fecundity per female was 69.3 at 25 C. The highest intrinsic rate of natural increase (r$\_$m/) and the highest net reproduction rate (R$\_$o/) were 0.241 at 30$^{\circ}C$ and 56.56 at 25$^{\circ}C$. The optimum temperature range for the growth of D. smithi was between 25$^{\circ}C$ and 30$^{\circ}C$.

• Korean journal of applied entomology
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• v.41 no.3
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• pp.205-209
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• 2002

Effects of temperature on the development and reproduction of the Udea ferrugalis Hubner were investigated at various temperatures (10, 15, 18, 20, 23, 25, 27, 30$\^{C}$). The development times of eggs, larvae, prepupae and pupae were shorter in higher temperatures than in lower ones. Egg and pupa did not develop at 10$\^{C}$. The lower developmental threshold temperatures for eggs, larvae, pupae were 9.5, 9.6 and 11.9$\^{C}$, respectively, and their thermal requirements for development completion were 87.9, 200.9 and 119.7 degree-days at the same temperature, respectively. Adult longevity was 25.2 days at 15$\^{C}$, 7.3 at 23$\^{C}$ and 5.3 at 30$\^{C}$. Mean fecundity per female was higher at 20-23$\^{C}$ compared to other temperatures. Mean generation time in days (T) was shorter in higher temperature region. Net reproductive rate per generation (Ro) was lowest at 15$\^{C}$ (138.2) and it was highest at 20$\^{C}$ (265.4). The intrinsic rate of natural increase (r$\_$m/) was highest at 25$\^{C}$ as 0.247. As a result, it was considered that optimum range of temperature for U. ferrugalis growth was 20.0 to 23$\^{C}$.