• Korean Journal of Fisheries and Aquatic Sciences
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• v.2 no.1
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• pp.1-15
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• 1969

A study on the complete zoeal development and the glaucothoe of Pegurus lenuginosus de Haan wvas conducted in the laboratoy. 1) P. lanuginosus had four zoeal stages and a single glaucothoe stage. 2) At mean temporature $13.6^{\circ}C$ and mean salinity $33.67\%_{\circ}$, total duration of the zoeal stages was approximately 31-32 days. 3) The zoeal larvae of P. lanuginosus can be easily distinguished from those of other Pagurus species in having 7+7 telson processes of which number as well as shape is consistent throughout all the zoeal stages. 4) The antennal exopodite bears five pulmose setae, and the endopodite is naked throughout the zoeal stages. 5) The 6th abdominal segment has no mid_dorsal spine on its posterior margin during the 3rd and 4th stages. 6) The basipodites of uropod are naked on the distal margin. 7) Mandibular palp is absent in the 4th stage. 8) Antenna of glaucothoe is long extending far beyond the chelipeds. 9) Ocular scale is absent in the glaucothoe. 10) Glaucothoe has 3+3 telson processes on the distal margin of the telson.

• The Korean Journal of Malacology
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• v.31 no.3
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• pp.179-186
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• 2015

The Pacific oyster Crassostrea gigas oocytes were exposed to 4 cryoprotectants, dimethyl sulfoxide (DMSO), ethylene glycol (EG), methanol, or polyethylene glycol (PEG), each with 4 four concentrations (5, 10, 15, and 20%) and for 10, 20, 30 or 40 minutes for permeation. The oocytes were then fertilized, using normal sperm of the species. Fertilization and hatching rates were clearly influenced by cryoprotectant species and their concentration and permeation time. Overall, they decreased as concentrations and permeation time of cryoprotectants increased with optimum results at concentrations of 5-10% and a permeation time of 10 minutes. Larval abnormalities, a sign of the chemical damage, were a representative phenotype which was higher at a higher concentration and longer duration of the chemicals. In conclusion, best result was from 5% DMSO exposure for 10-20 minute permeation.

• Journal of Sericultural and Entomological Science
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• v.41 no.3
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• pp.154-166
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• 1999

General characteristics and life span of silkworm moth were investigated amongst 277 gene resources preserved and maintained in Korea. Silkworm varieties were classified according to the commercial characteristics and the viability of tested varieties. There were significant differences among the eight different commercial characteristics of silkworm such as whole larval period, duration of 5th instar, pupal body weight, single cocoon weight, cocoon shell weight, cocoon shell ratio, cocoon yield and longevity, Tropical race showed the longest life span among the other five geographical races, and followed by Japanese, European, Chinese and Korean race in order. In the longevity of each variety, Daizo(sdi) showed the shortest life span with 4.3days, and J037 was the longest as 16.0 days. Average longevity of female was 11.1 days as showed 3.0 days longer than that of male which was 8.2 days. Total average longevity of the whole varieties was 9.7days. In the correlation between the longevity and commercial characteristics, there was a tendency that the commercial characteristics became better when the life span was longer. According to the result of Complete Linkage Cluster Analysis, the genetic resources of 277 silkworm varieties classified into 5 groups such as “Group I”for short life span with low cocoon yielding “Group II”for middle life span with middle cocoon yielding,“Group III”for the shortest life span with low cocoon yielding, “Group IV”for high pupation rate and the highest cocoon yielding with comparatively long life span, and “Group V”for the longest life span with comparatively high cocoon yielding.

• Journal of Sericultural and Entomological Science
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• v.28 no.1
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• pp.37-42
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• 1986

The experiment was carried out to investigate the effects of juvenile hormone analogue on changes of protein and amino acids in haemolymph of silkworm larva. Juvenile hormone analogue was topically administered to larvae at dose of 1$\mu\textrm{g}$ 10$\mu\textrm{g}$ per gm of body weight at 60hr. of the 5th instar. The results obtained were as follows ; 1. Larval duration of the fifth instar was extended about 1 day by JHA-1 and 4 days by JHA-10 as compared with the control. 2. Cocoon weight and cocoon layer weight by topical application of JHA were heavier than those of the control, but cocoon layer ratio was decreased in JHA-10 to the exclusion of JHA-1. 3. The concentration of haemolymph protein during the fifth instar was increased remarkably by the JHA application. 4. The total content of amino acids in haemolymph proteins of JHA-10 approximately doubled that of the control, with the conspicuous increase of glycine and arginine level.

• International Journal of Industrial Entomology and Biomaterials
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• v.37 no.2
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• pp.73-81
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• 2018

The giant mealworm beetle, Zophobas atratus (Coleoptera: Tenebrionidae), is a tropical beetle. As this beetle can be used as an ingredient in animal feed, the effects of brewer's spent grain (BSG) on the development and nutritional value of Z. atratus were investigated. As results, there were no significant differences on the larval survival rate, body weight, and duration at different content of BSG, mixed with conventional feed, wheat bran (WB). Based on these results, BSG can be mixed with wheat bran as a Z. atratus food ingredient without any problems. The nutritional value was compared between 100% wheat bran control and 50% BSG experimental groups. The moisture, crude protein, carbohydrates, and amino acids were 1.1-1.4 times higher in the 50% BSG group. In the BSG group, the linoleic acid content was 1.6 times higher than that in the control group. In the wheat bran group, the oleic acid content was 38.4%, which was 1.3 times higher than that in the BSG group. As minerals, the control and BSG groups showed high potassium and phosphorus contents. In terms of hazardous materials, four heavy metals (lead, mercury, arsenic, and cadmium) and two microorganisms (Escherichia coli and Salmonella spp.) were not detected. There were no significant differences in developmental characteristics between the wheat bran and BSG mixed groups, and the nutritional values were better in the BSG mixed group. Therefore, BSG can be used as alternative food source for rearing Z. atratus.

• Journal of Environmental Science International
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• v.33 no.1
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• pp.97-102
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• 2024

We introduce a method for preserving yellow mealworm (Tenebrio molitor Linnaeus) larvae for an extended period and show that a high percentage of larvae can survive in good health under low-temperature storage conditions combined with specific diapause termination conditions. Our study revealed that we can regulate important development stages such as pupation, emergence, and larval duration by adjusting these termination conditions. When storing larvae aged 6-8 weeks for 140 days, the storage temperature can be varied based on our goals, giving us control over yellow mealworm production to meet specific demands. To produce adult beetles, storing larvae at 15 ℃ with wheat bran and ending diapause at 30 ℃ resulted in 90% pupation rate, with 60% becoming adults in 21 days. If our aim is larvae production, storing them at 10-12 ℃ with wheat bran and ending diapause at 25-30 ℃ allows the larvae to reach a suitable weight for processing. This straightforward approach ensures long-term storage of yellow mealworm larvae and provides a practical way to control their development, allowing efficient mass production tailored to market demands.

• International Journal of Industrial Entomology and Biomaterials
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• v.18 no.2
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• pp.105-112
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• 2009

The greenhouse whitefly, Trialeurodes vaporariorum (Westwood) and the sweet potato whitefly, Bemisia tabaci (Gennadius) are serious insect pests that have a wide host range including cucumber, tomato, and pepper. In this study, we tested larvicidal efficacy of several on-the-market environment-friendly agricultural materials (EFAM) to select the effective products after the target pests were stabilized in indoor rearing condition. The developmental periods of two whiteflies are as follows: in the case of T. vaporariorum, egg duration is 9.6 days and nymph is 18.9 days, and in the case of B. tabaci, egg duration is 7.4 days and nymph is 15.2 days under $25^{\circ}C$ with relative humidity (RH) of $60{\pm}5%$ and a photoperiod of 16 L:8D. The total period of T. vaporariorum was 5 days longer than B. tabaci. Among 22 EFAMs six products showed more than 60% of insecticide efficacy against T. vaporariorum BTV B, BTV D, BTV G, BTV L, BTV M, and BTV S. On the other hand, seven EFAM products showed over 60% of insecticide efficacy against B. tabaci BTV D, BTV G, BTV K, BTV L, BTV M, BTV N, and BTV U. In the case of Spodptera litura previously, 16 EFAMs were tested against $2^{nd}$ instar S. litura, and six EFAMs were found to have more than 90% efficacy. Test of these six EFAMs against entire larval stages were performed in this study. Although some of these products showed still more than 90% of insecticidal efficacy against up to $3^{rd}$ instar larvae, the efficacy of these EFAMs sharply decreased as ages increase, resulting in less than 60% of efficacy of the products at most. This result indicates the difficulty to control S. litura with the on-the-market EFAMs alone under economic injury level. Collectively, it is required to find more EFAMs, and find alternative method, and combined way of controlling to control those insect pests tested in this study.

• Korean journal of applied entomology
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• v.44 no.2
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• pp.109-114
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• 2005

This study was conducted to investigate the life cycle of Tipula latemarginata Alexander in Korea. The field surveys for the life cycle of the species were carried out at the two sites of Neaseong Stream area in Bongwha County from January 2001 to December 2002. Also many individuals of the species were reared in laboratory to investigate the life cycle. T latemarginata appeared to have three generations a year under the rearing conditions at room temperature. All the processes of life cycle of the species, when reared at room temperature from September 2001 to March 2002, were as follows: Eggs usually hatched between 4 and 10 days after oviposition. First instar larvae grew rapidly and molted to the second instar in 7-9 days. Second instar larvae spent 5-7 days for next molting and third instar period lasted approximately 8-12 days. Fourth instar larvae spent 6 weeks to 5 months for pupation. Especially the duration of fourth instar larval existence was greatly lengthened and served as the overwintering stage. The duration of pupal stage was 6-10 days. In the field, T. latemarginata also appeared to have three generations a year at the favorable habitats.

• Journal of Aquaculture
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• v.6 no.4
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• pp.255-271
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• 1993

For the development of seedling production techniques of the freshwater crab Eriocheir japonicus, the effects of salinity and temperature on the growth of larvae of the crab were studied. Embryos hatched out as zoea larvae were measured 0.421 mm in average carapace length. Five zoea stages needed 16-26 days for metamorphosis from zoea to megalopa at $22^{\circ}C$ and $24.5\%o$. The average carapace length of the 5th zoea was 1.16 mm and that of the megalopa larvae was 1.89 mm. Each zoea stage could be identified based on both the number of plumosed seatae on the exopodite of maxilliped, and the number of spines on the posteroinner margin of tel son and also based on the rudimentary pleopods appearence. Zoea larvae fed rotifers and Artemia nauplii were healthy and metamorphosing rate from zoea to megalopa was $80\~90\%\;at\;22\~26^{\circ}C\;and\;17.5\~31.5\%o$. The relationship between larval period (Y in days) and water temperature $(X\;in\;^{\circ}C)$ is expressed as Log Y = 3.8604-1.91735 LogX. Water temperature and salinity ranges for better survival and metamorphosis of the larvae were $ 22^{\circ}C\~26^{\circ}C\;(optimum\;at\; 26^{\circ}C)\;and\;17.5\%o\~31.5\%o\;(optimum\;at\;24.5\%)$, respectively. The duration of larval stages tend to longer as salinity levels deviated from optimum particulaly at lower end. All zoea larvae did not survive in freshwater.

• Korean journal of applied entomology
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• v.46 no.2
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• pp.201-212
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• 2007

This study was conducted to investigate the biology of three species, Tipula latemarginata Alexander, T. nova Walker and T. aino Alexander, of the Genus Tipula in Korea. Field surveys for the biology of the species were carried out at the three sites of Neaseong Stream area in Bongwha County from January 2001 to December 2005. Also many individuals of the species were reared in laboratory to investigate the biology. The larval habitats of the species were streams, rivers, paddy fields, damp earth or leaky revetments. The Tipula larvae were herbivorous. Newly-hatched first instar larvae fed on soft algae, and the larvae gradually fed on leaves, stems and roots of a variety of plants or hard leaf litters, as they grew. During the molting of the larvae their body kept moving from left to right and up and down. Molting usually took not more than 2 hours, and about four hours after molting, the larvae started to eat heavily. The Tipula larvae in aquatic places moved to drier land for pupation and went through short prepupal stage lasting 1-2 days for pupation at fourth instar larval stage. When emerging, the Tipula pupae placed their head and thorax on the earth, but the other parts in the earth. Emergence from the pupal case required about 20 min. to one hour. Mating of Tipula adults took place within 5-7min. after emergence and the duration of mating was about 40 min. The female adults of the species laid eggs by walking with 3 pairs of legs over the damp earth or algal beds. Their body was positioned vertically on the ground with their wings spread $120^{\circ}$ and legs landed on the surface. The oviposition usually took place from one day to 4 days after emergence and the number of eggs carried by female adults were an average of 501-760 per individual. Tipula adults didn't normally feed, and drank water only occasionally. For a few days after emergence, the adults reared in the laboratory rarely drank water. As they neared to death, however, they frequently drank water. The longevity of adults reared in the laboratory with only water during the summer was ca. 4-9 days and males usually survived a little longer than females. The longevity of T. nova was increased 3 times or more as much by feeding them 3% sugar water. Male adults of T. latemarginata outnumbered female adults by 2.6 : 1 in the fields.