• Journal of Sericultural and Entomological Science
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• v.27 no.1
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• pp.18-23
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• 1985

This study was carried out to investigate the effect of the difference of dietary compositions and environmental conditions on the growth and development of silkworm. The results obtained are as follows: 1. The more amount of soybean meal of diet was added, the more duration of the larval period was shortened. But Fifty percent increase of the amount of protein of diet leongthened the duration of larval period. 2. Fifth percent addition of the soybean meal to the diet does not influence the silkworm mortality, Whereas more than that gives rise to the adverse effect on the silkworm mortality. 3. The cocoon quality was significantly affected by the difference of dietary compesition. 4. In the environmental condition the duration of larval period was shortened in the high temperature and the dark condition. 5. The silkworm mortality was increased in the high temperature and the light condition. 6. The cocoon quality was significantly affected in the high temperature and the dark condition.

• Korean journal of applied entomology
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• v.41 no.2
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• pp.85-89
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• 2002

Development and reproduction of the rice armyworm, Pseudaletia separara, were investigated on different diets (corn leaf, rice leaf, Chinese cabbage leaf, cabbage leaf, sweetpotato leaf, soybean leaf and silkworm artificial diet). Egg and pupal periods were not different among the diets. But larval periods showed significant difference among diets. Developmental period from egg to adult was shortest as 32.5 d on corn leaf and longest as 46.6 d on soybean leaf. At 16 days after hatching, larval weights on rice and silkworm artificial diet were heavier than those on other diets. The larvae reared on cabbage leaf and sweetpotato leaf failed to pupate. Survival rates from larva to adult were highest (70.6%) on com leaf lowest (39.8%) on soybean leaf. The longevity of female adults was not affected by the larval diets. Female adults showed higher fecundity when the larvae were fed with corn leaf, rice leaf and silkworm artificial diet than other diets. Net reproduction rate (R$_{0}$) was highest as 1218.5 on silkworm artificial diet. The intrinsic rate of natural increase (R$_{0}$) ranged from 0.115 to 0.175, and was maximum on com leaf.

• Animal cells and systems
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• v.1 no.1
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• pp.107-113
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• 1997

Antisera against the myotropic neuropeptide leucokinin I, originally isolated from head extracts of the cockroach Leucophaea maderae, have been used to investigate the distribution of the leucokinin I-immunoreactive (LK I-IR) neurons in the brain of the common cutworm, Spodoptera Iitura, during postembryonic development. The LK I-IR neurons are found at the larval stages (excluding first instar larval stage), pupal stages, and adult stage, of which the brains have been examined in this experiment. The number of the LK I-IR neurons in the brain increases from the second instar larva to the fifth instar larva which has about 32, the largest number in all postembryonic stages. Thereafter, the LK I-IR neurons begin to decrease in number. During the pupal stages, smaller number of LK I-IR neurons persist in the brains; 6 or 4. At adult stage the brain contains 8 LK I-IR neurons. The LK I-IR cell bodies are distributed in each dorsal cortex of both cerebral hemispheres in the second instar larva and through all the neuromeres of the brain during later larval stages, despite of being a large number of the LK I-IR cell bodies in dorsolateral neuromeres. At pupal stages, most of the LK I-IR cell bodies are found in the pars intercerebralis. Extremely small number of the LK I-IR cell bodies are localized in the pars lateral is. Adult brain contains the LK I-IR cell bodies in the pars intercerebralis and the middle cortex of the posterior brain. The LK I-IR nerve processes can be easily found in the neuropils of almost all the neuromeres in the brains of third, fourth, fifth and sixth instar larvae. Most of the LK I-IR nerve fibers in those brains are originated from the LK I-IR cell bodies located in the brains. The LK I-IR cell bodies which have very weak reactivities to the antisera do not show projection of the LK I-IR nerve processes in the brains.

• Korean Journal of Ichthyology
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• v.35 no.2
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• pp.91-100
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• 2023

The early life history of Silurus microdorsalis living in Jahocheon Stream was studied by observing egg and morphological development. Live fish were captured in June 2018, then reared in a circulating filtration system under a 14L : 10D photoperiod with a water temperature of 18℃. To artificially induce spawning, females were injected with 0.5 mL of Ovaprim (Syndel, Nanaimo, BC, Canada) per kg of body weight, and males were injected with 10,000 IU/kg body weight of human chorionic gonadotropin. Approximately 15 h later, eggs were artificially inseminated by the dry method. Mature eggs were light pale yellow, which separated them from immature eggs. Fertilized eggs were 2.16±0.06 mm (n=8) in diameter and fully hatched at 181 h after fertilization. The fertilization rate was 63.1±2.2%, and 10.0±3.7% of the embryos were malformed at 18℃. The rates of development were 181 h at 18℃, 109 h at 21℃, and 76 h at 24℃. The larval size immediately after hatching was 4.64±0.22 mm (n=8), and the larvae displayed negative phototaxis at 1 day after hatching. The total larval length on 7 days after hatching was 12.47±0.53 mm, with 25~30 basal anal fin rays and 14~16 basal caudal fin rays observed. The total larval length was 14.13±0.51 mm on 9 days after hatching, and approximately 90% of the black endoplasmic reticulum was deposited on the head and body. The dorsal fin had formed, and a single basal body was observed. On 15 days after hatching, the total larval length was 16.69±0.31 mm; the number of basal caudal fin rays (18 poles) was an integer because 2 dorsal fin basal rays and 60~63 anal fin basal rays were observed. The total larval length was 28.96±1.10 mm on 50 days after hatching; the numbers of caudal fins (n=18), dorsal fins (n=3), pectoral fins (n=11), and anal fin basal rays (n=67~73) were integers.

• International Journal of Industrial Entomology and Biomaterials
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• v.34 no.2
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• pp.17-22
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• 2017

Cooked mature silkworms have received increasing attention as a new source of income for sericultural farms. Quality improvement of these worms as the end-product requires prevention of the following: inclusion of unfertilized silkworm eggs, mixing with impurities, producing undercooked or overcooked mature larvae, and mixing spewed silk substance. Preventing unfertilized eggs and impurities and reducing undercooked or overcooked mature larvae can be achieved by sericultural farms. However, the prevention of spewed silk substance requires the development of new techniques. This study developed new techniques for optimum cold storage temperature, soaking, and hydro-thermal treatment to minimize the spewing of mature larvae prior to steaming: when larvae mature after 7 days on the $5^{th}$ instar, they should be soaked in water at room temperature of $25^{\circ}C$ immediately upon collection and stored at $8^{\circ}C$ for less than 3 days. They should be soaked in boiling water for approximately 10 s immediately before steaming to kill the larvae and cooked with steam. This method allows for the production of high-quality mature larvae without spewed silk substance. These new techniques will considerably improve the production of well-cooked quality mature larvae by minimizing silk substance spewed out from the larvae.

• BMB Reports
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• v.44 no.6
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• pp.387-392
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• 2011

To investigate the molecular scavenging capabilities of the larvae of Hermetia illucens, two serine proteases (SPs) were cloned and characterized. Multiple sequence alignments and phylogenetic tree analysis of the deduced amino acid sequences of Hi-SP1 and Hi-SP2 were suggested that Hi-SP1 may be a chymotrypsin- and Hi-SP2 may be a trypsin-like protease. Hi-SP1 and Hi-SP2 3-D homology models revealed that a catalytic triad, three disulfide bonds, and a substrate-binding pocket were highly conserved, as would be expected of a SP. E. coli expressed Hi-SP1 and Hi-SP2 showed chymotrypsin or trypsin activities, respectively. Hi-SP2 mRNAs were consistently expressed during larval development. In contrast, the expression of Hi-SP1 mRNA fluctuated between feeding and molting stages and disappeared at the pupal stages. These expression pattern differences suggest that Hi-SP1 may be a larval specific chymotrypsin-like protease involved with food digestion, while Hi-SP2 may be a trypsin-like protease with diverse functions at different stages.

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.142.1-142
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• 1998

No Abstract, See Full Text

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.1
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• pp.1-9
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• 2014

One of freshwater rotifer (Brachionus calyciflorus) is very useful as a live food organism for early larval rearing of freshwater aquaculture industry. However, the knowledge about freshwater rotifer culture is scarce. On the other hand, marine rotifer culture as live food organisms is done, almost perfectly. In this study, I show to be benefit experimental results for successful freshwater larval rearing through the observation with microcosm structure in freshwater rotifer culture tanks.

• Animal cells and systems
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• v.10 no.1
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• pp.7-14
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• 2006

Novactaea pulchella was reared in the laboratory, from hatching to the megalopal stage at $25^{\circ}C$. The larval stage of it consists of two zoeal and one megalopal stages. The first zoea of the present study differs from that described by Terada (1990) in the setal presence of the carapace, the maxilla and the maxilliped, and the lateral process on the abdominal somite. It is reported for the first time that brachyuran zoeas belonging to a species share two types of lateral processes on the abdominal somites. They are either on the abdominal somites 2 and 3 or on abdominal somites 2 to 5. A provisional key is provided to aid the identification of the actaeine zoeas in Korea and the adjacent waters.

• Animal cells and systems
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• v.14 no.2
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• pp.129-136
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• 2010

The introduced spider crab Pyromaia tuberculata was collected from Korea in 2005 and it was ovigerous. After hatching, larvae were reared in the laboratory at $20^{\circ}C$. The larval stage of the species consists of two zoeal and one megalopal stages. The larvae of the Korean species differ somewhat from those from New Zealand described by Webber and Wear (1981; N Z J Mar Freshwat Res. 15:331-383) and from Brazil described by Fransozo and Negreiros-Fransozo (1997; Crustaceana. 70:304-323.) in the setal presence of the antennule, the maxillule, the maxilla and the maxillipeds, and the abdomen. It is found that Fransozo and Negreiros-Fransozo have overlooked some setae on the basis of the zoeal maxillipeds and that re-examination of their larvae is needed. Also, it is found that the Inachoididae is heterogeneous based on the zoeal morphology because two distinct groups exist in the family.