• Korean journal of applied entomology
• /
• v.61 no.1
• /
• pp.165-172
• /
• 2022

Insects have evolved successfully by adapting to their environments through development and reproduction. Temperature-dependent models have been used to calculate the intrinsic optimal, optimal development, and optimal fecundity temperatures of insects and mites; for this study, we reviewed 112 works that focused on these parameters. The insects and mites investigated in this study include 14 Acari, 8 Coleoptera, 5 Diptera, 31 Hemiptera, 7 Hymenoptera, 18 Lepidoptera, 1 Orthoptera, 5 Psocoptera, and 5 Thysanoptera species. The results of this study showed that the interval distance between the intrinsic optimal and optimal fecundity temperatures was smaller than that between the intrinsic optimal and optimal development temperatures of the all insects and mites investigated except for those in the order Thysanoptera. We found that there is a close relationship between the intrinsic optimal and optimal fecundity temperatures.

• Korean journal of applied entomology
• /
• v.35 no.1
• /
• pp.52-57
• /
• 1996

This experiment was carried out to evaluate the effect of sublethal doses of BPMC, etofenprox,and buprofezin on N. lugens. and its predator C. lividipennis. Buprofezin was found to be the most toxic to N. lugens and the most safe to C. lividipennis among the three insecticides, based on LD50 values. Selective toxicity index calculated by dividing LDSo value of C. lividipennis by that of N. lugens indicated that buprofezin was very safe to C. lividipennis, showing selective toxicity of 2703.3. Longevity and fecundity of N. lugens treated with LDIU and LDm of buprofezin and BPMC were not significantly different with those of untreated brown planthoppers. However, egg hatchability' of N. lugens was greatly reduced when treated with LDm of buprofezin, having the highest inhibition rate of 17.7%. Hatchability of eggs from insects treated with BPMC was similar to that of control. The oviposited peak of treated hoppers appeared late as compared to the untreated which showed the peak at early part of the ovipositional period. The longevity and fecundity of C. lividipennis treated with BPMC were significantly reduced as compared with the untreated. Etofenprox also induced fecundity reduction when treated with LDlo, and LDm. However, C. lividipennis treated with sublethal doses of buprofezin showed no redution in logevity and fecundity. From these results, it may be said that buprofezin can be used to control brown planthopper without disrupting of C. lividipennis population in the rice field.

• Korean Journal of Poultry Science
• /
• v.17 no.4
• /
• pp.255-268
• /
• 1990

This study was carried out to investigate the time-trends of genetic parameters of the dosed flock population which selected for improving egg production. Data for two layer pure lines, Line-W (Single Comb White Leghorn) and Line-B (brown layer) which have been maintained at the Mani Breeding Farm were collected from 1980 to 1985 during 5 generations. The effective number of parents per generation ranged from 148 to 366 in Line-W and 85 to 355 in Line-B, and the cumulative expected inbreeding coefficients during 5 generations of selection were 15％ and 1.6％. So inbreeding could not be considered a critical factor on estimating the genetic parameters, heritabilities and genetic correlations Heritabilities of EN 300 and EN 400, primary two selected traits were significantly decreased during 5 generations but the estimates of the other 03its not showed the consistent decreasing pattern significantly. No time trends of probable consequence were evident in the genetic correlation coefficients of the traits studied. The reason for that situation was attributed to the fact that selection was conducted for multiple objectives and the relative importance of selection for the studied traits were not consistent by generations.

• Korean journal of applied entomology
• /
• v.53 no.4
• /
• pp.381-389
• /
• 2014

We investigated the host fruit, seasonal occurrence, and oviposition habits of the eurytomid wasp, Eurytoma maslovskii that cause Japanese apricot fruit drops. This eurytomid wasp was found to occur in Gyeonggi-do, Chungcheongbuk-do, Chungcheongnam-do, Jeollanam-do, and Jeollabuk-do in Korea, and it attacked seeds of Japanese apricot, apricot, and peach. Overwintered larvae were observed until mid April, inside the stone of Japanese apricots. Pupation took place between late March and late April. More than 90% of the adult wasps emerged between late April and early May. The female wasps laid eggs just under the seed coat before endocarp hardening. The length of the wasp ovipositor was at least 5 mm, and hence, the diameters of fruits for oviposition would not exceed 2 cm. We observed up to five eggs per fruit, and the egg stage did not last for more than two days. Newly hatched larvae moved to the embryo, which is the first part that forms in a seed, and feeds on this. Larval competition occurs during this time; in this study, only one larva survived and matured. Thus, from the larva cycle of the wasp, most of the damaged fruits would have fallen by early June, before the harvest period.

• Korean Journal of Ichthyology
• /
• v.26 no.2
• /
• pp.83-88
• /
• 2014

An endemic Korean bitterling, Acheilognathus signifer, known as using freshwater mussels for its spawning activity, much prefers Lamprotula leai in Dalcheon stream (Goesan population) and Unio douglasiae sinuolatus in Gadaecheon (Danyang population) stream, Korea. The spawning pattern between two mussels and one bitterling was carried out in two populations from April to June, 2011 and 2013. L. leai in the Goesan population was bigger shell length and have more eggs, larvae or both with A. signifer than those of U. d. sinuolatus in the Danyang population. Also, A. signifer in the Goesan population appeared to have a longer ovipositor and lay ripen eggs more than those of A. signifer in the Danyang population. Glochidium, a larval stage, of some L. leai in the Goesan population was incubated in all the demibranch, whereas for all of U. d. sinuolatus in the Danyang population was found in the outer demibranch only. For L. leai in the Goesan population, the eggs, larvae or both of A. signifer were much more in the non-breeding mussels (giving no glochidium) than the breeding mussels having the glochidium. For U. d. sinuolatus in the Danyang population, in contrast, the non-breeding mussels have fewer eggs, larvae or both less than the breeding one.

• Korean Journal of Ichthyology
• /
• v.7 no.2
• /
• pp.195-202
• /
• 1995

The seasonal changes in the muscle components of hibernant fish, amphibious mudskipper (Boleopthalmus pectinirostris), caught during the period between June 1993 and April 1994 were studied. The distributional changes of its major components in each muscle tissues was also observed before and after spawning and hibernation. Moisture content was the lowest after spawnig season and the highest just after hibernation, but crude protein was the highest after spawning sea-son. Crude lipid in female was the highest before spawning season, while in male it was the highest after spawning season, but both of female and male the lowest just after hibernation. Carbohydrate content in female and male showed the highest value just before hibernation and tended to decrease thereafter. In case of mudskipper, dyeing distribution was more or less spread in almost all of the tissues after spawning season but showed nearly no difference just after hibernation with the exception of small increase in dyeing degree of muco layer and epidermis layer. Investigation of mudskipper muscle tissue through the method of sudan black B dyeing yielded the results as follows ; lipid component in mudskipper in seasons before and after spawning season was percieved as mainly distributed in muco layer, epidermis and hypodermis layer respectively and also percieved a little between hypodermis subscutoneus cells. In season just before hibernation, it prevailed in almost all of the tissues, contrary to the weakness in its distribution degree just after hibernation.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.3 no.1
• /
• pp.67-74
• /
• 1999

In this study, coda Q has been determined by the single scattering model in the Kyeongsang Basin region using the decay of the amplitudes of coda waves on bandpass-filtered seismograms of local microearthquakes in the frequency range 1.5~18 Hz. Reported frequency dependence of Q is of the form $Q_C=Q_O^n$$(83.9{ll}Q_0{ll}155.9,;0.76{ll}n{ll}1.05$. Considering a model incorporating both scattering and intrinsic attenuation, and assuming that the attenuation is entirely due to the scattering loss, the minimum mean free paths are about 51~56 km and the coefficients of inelastic attenuation(${\gamma}$) are between 0.0093 and 0.0098 were found. Earthquake-station paths pass through the fault zone show high attenuation and strong frequency dependency compared to other ones.

• Journal of Aquaculture
• /
• v.17 no.1
• /
• pp.81-88
• /
• 2004

Annual gametogenic cycle of Manila clam Ruditapes philippinarum collected from Shi-Heung-Ri beach in Jeju was investigated for the 12 month period from May 2001 to April 2002. Water temperature varied from 10 to 27$^{\circ}C$ and salinity from 27 to 35 psu during the course of study. Most of the clams collected in March were in indifferent or in early developing indicating that clams initiated gametogenesis when water temperature becomes 14 to 15$^{\circ}C$. In early June, most of the clams were in developing, expanding follicles and exhibiting growing oocytes. Fully ripe gonads were observed in clams collected during late June to early August. Spawning clams were observed as early as in early June although the spawning activity reached its maximum in early August. Condition index (CI) was rapidly increased from July to early August and then dropped in late August, indicating that most of clams in Shi-Heung-Ri beach spawn in late summer when water temperature was within a range of 25 to 27$^{\circ}C$.

• Proceedings of the Korea Society of Poultry Science Conference
• /
• 2003.11a
• /
• pp.103-104
• /
• 2003

This experiment was conducted to investigate the effect of enhancement of protein, limit amino acid, Ca and P on egg Production and egg qualify in laying hens. 720 twenty five week of age (WOA) brown laying hen divided to two diet to seventy WOA. Conventional diet(control) formulated by NRC recommendation, 2,900 ME kcal/kg, 16.0 ％ crude protein, 0.768 ％ lysine, 0.332 ％ methionine, 3.5 ％ Ca and 0.275 available P. Enhanced diet(ED) formulated by increasing about ten percentage except ME and available P : 2,900 ME kcal/kg, 17.7 ％ crude protein, 0.845 ％ lysine, 0.368 ％ methionine, 3.99 ％ Ca and 0.275 available P. Overall egg Production were not difference by diets though the hens fed control diet tended to higher egg Production to sixty WOA. Average egg weight was heavier in the ED than control in all period(P＜0.05). Daily egg mass increased slightly in the ED, but there were not significantly difference. Average feed intake increased about 3g in the control compared to the ED. Feed conversion ratio significantly improved in the ED(P＜0.05). Egg shell breaking strength was stronger in ED by around sixty WOA and showed similar tendency after that. Egg shell thickness was certainly improved in ED. Haugh unit. egg shell color and egg yolk color were not difference by diets.

• 한국해양학회지
• /
• v.24 no.4
• /
• pp.172-183
• /
• 1989

Acoustical estimation of vertical distributions of zooplankton was carried out by using the backscattered signals of ADCP which was deployed in the Korea Strait in September, 1978. the backscattered signals of ADCP represents the total backward sound intensity caused by the scatters existing within the insonified water column of 8m deep. Based on these backscattered intensities, the estimated number of individual zooplankton (namely, Copepods) varies with depth such that in the surface layer above the thermocline, the numbers are exceedingly larger than the lower layer. It is also shown that a relatively larger number of individuals exists in the bottom cold water layer in the centeral part of the Strait. The horizontal distribution of the zooplankton in the surface layer across the west channel of the Strait shows that the number is higher in the coastal zone of the Korea and it decreases toward the central and then remains constant up to the vicinity of the Tsushima Island where it increases again. This type of distributions is well fitted to the one obtained at several stations by the conventional method at least in qualitative way. Therefore, it is quite plausible to use the ADCP data for monitoring the spatial and temporal distributions of zooplankton.