• International Journal of Industrial Entomology and Biomaterials
• /
• 제9권2호
• /
• pp.269-272
• /
• 2004

Different methods of cold storing of bivoltine eggs are in practice to postpone hatching. Bivoltine eggs undergo hibernation if they are not acid treated within 20 - 24 hrs of oviposition, which depends on race, ambient temperature and humidity. The schedules adopted for cold storing include hibernation schedule (Hib), ordinary chilling (OC), short term chilling (STC) and acid treated layings (AT). Peanut cocooning race ${NB_4}{D_2}$ has been subjected for the present assessment. Cocoons harvested from the crop pertaining to all the four methods of cold storing have been used for producing different combinations and acid treated followed by rearing. The performance in respect of chawki loss, maximum larval weight 4({5^th} age)$, yield/ 10,000 larvae (no), cocoon and shell weight showed maximum values for hibernation ${\times}$ hibernation combination followed hibernation with OC and hibernation with AT. Lowest performance was recorded when STC batch source females were used.

• 한국잠사곤충학회지
• /
• 제37권2호
• /
• pp.235-243
• /
• 1995

Recently, the cocoon production is reducing very steeply in Japan. The main reason for this cocoon reduction is due to high labor cost and the production expense is apt to rise year by year. Accordingly, the improvement of cocoon productivity by retrenchment of the production expense is intensively required in my country. Therefore, the silkworm rearing on the artificial diet is largely expected as the innovation techniques of sericulture. Since rearing of the silkworm on artificial diets has first been achieved in 1960, and the silkworm larvae were reared throughout all the instars on artificial diets(Fukuda et al., 1960, Ito & Tanaka, 1960). The artificial diets used at this time contained 50% or more of dried, pulverized mulberyy leaves as one of the main ingredients, and the composition was rather simple. When reared on these diets, larval growth and development were retarded, small cocoons appeared, and the adults laid only a small number of eggs. At first, we would like to study about nutritional requirement of the silkworm, using the chemically defined diet which prepared artificially. Subsequently, attempts were made to improve the diets by replacement of crude ingredients with possibly purer compounds, as mentioned later. Before giving the details on individual nutrient, I would like to summarize about the outline of utilization flow of various nutrients through the larval-pupal development and these daily quantitative requirements per body weight in the silkworm when they were reared on mulberry leaves.

• Fisheries and Aquatic Sciences
• /
• 제13권4호
• /
• pp.308-314
• /
• 2010

Larvae of Palaemon serrifer were reared in the laboratory under three different temperature regimes ($15^{\circ}C$, $20^{\circ}C$, $25^{\circ}C$) to study the effects of rearing temperature on larval survival and growth, as well as other traits such as embryo volume, number of embryos (fecundity), incubation period, development. Mode and development period. Growth pattern was analyzed by measuring the molt increment and intermolt period. The intermolt period consistently increased with size and instar number and was shortest at $25^{\circ}C$. However, molt increments generally decreased with instar number. Number of embryos varied from 552 to 1355. The relationship between the number of embryos and carapace length was expressed by the equation (fecundity) y=2.7744x+0.208 ($R^2$=0.7961). Egg volume was a primary factor affecting other life-history traits. Egg volume was $0.078\;m^3$, which is relatively small thus embryos exhibited a relatively short incubation period and a comparatively short development period, and the nutritional mode was planktotrophic. Brood production was followed by a fast parturitional pattern. Most ovigerous females had mature ovaries when the parturial molt occurred soon after eclosion.

• 한국환경과학회지
• /
• 제30권2호
• /
• pp.191-194
• /
• 2021

This study aimed to provide information and data for the management of insect breeding farms by identifying the appropriate density when rearing Protaetia brevitarsis larvae. The breeding box of the insects was filled with 2 L of fermented sawdust on a 50 × 35 × 15 cm sheet of plastic, and the density of the treatments was 200, 300 and 400 P. brevitarsis in the first, second, and third larval stages. Each treatment was repeated five times, and the sawdust medium was replaced three times (10 intervals). The experiments were conducted for a total of 30 days from March 1, 2020. Overall, 200 P.brevitarsis in the first, second, and third larval stages reared in the breeding box had a higher average survival rate and lower average mortality rate, thereby contributing to efficient production. In conclusion, this result suggests a way to increase production efficiency through the environmental management of insect breeding farms.

• 한국수산과학회지
• /
• 제2권1호
• /
• pp.87-91
• /
• 1969

보리새우의 대량종묘생산을 목적으로 대형콘크리이트수조 A ($3.4\times1.9\times1.0m$)와 2개의 소형콘크리이트수조 B와 C($1.45\times0.85\times1.0$)를 이용하여 유생사육실험을 하였다. 1) 산난후 제1기 조이야까지의 발생기간은 사육수조에 차이없이 수온 $23^{\circ}C$ 내외에서 1.5-2일이 소요되었다. 그러나 조이야기 이후 차이가 생겨 Post-larva까지의 변태기간은 수조A에서는 산난후 19-20일, 수조B에서는 15-16일, 수조C에서는 16-17일이 각기 소요되었다. 2) 유생의 체장은 3개의 수조간에 차이가 없었다. 3) Post-larva는 산난후 36-40일경에 치하로 되었다. 4) 유생 사망률은 전유생 기간중 제1기조이야에서 제2기조이야로 변태하는 기간에 가장 높아서 수조A가$51.39\%$ 수조B가 $50.70\%$, 수조 C는 $31.90\%$를 나타내었으며 마이시스기이후는 비교적 안정된 상태를 나타내었다. 5) 노우플리우스기로부터Post-larva까지 기간의 유생 총사망률은 각수조 비슷하게 $75\%$ 내외를 나타내어 전체적으로 약 $25-30\%$의 종묘를 생산할 수 있었다.

• 한국수산과학회지
• /
• 제54권6호
• /
• pp.948-953
• /
• 2021

To find the optimal eggs to larvae transforming temperature of walleye pollock Theragra chalcogramma, we investigated their hatching pattern, mortality, and larval deformities. Results showed that the hatching quality decreased as the water temperature increased and dropped sharply above 13℃. The highest hatching rate was achieved at 7℃, whereas the lowest was at 15℃. Dead eggs were not observed at 7℃; however, dead egg ratios were significantly high at 4.5℃ and above 13℃ (P<0.05). Mortality of larvae after hatching was not observed at 4.5℃, but was significantly high above 13℃. The DNA content of the larvae did not show any significant difference at all water temperatures; however, RNA content was the highest at 7℃ and was significantly low above 11℃. In addition, RNA/DNA ratio was the highest at 7℃. Larval deformities after hatching were low at 7-11℃ and higher at higher or lower water temperature. Therefore, the hatching index and larval health index of Walleye pollock eggs in this study show that 7℃ to 11℃ seems to be the optimal transforming water temperature range.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제32권2호
• /
• pp.69-79
• /
• 2016

Distillers dried grain (DDG) and makgeolli spent grain (MSG) are agricultural byproducts to produce alcoholic beverage. However, they are known to contain enough nutrients. Mealworm is a promising insect resource for an animal feed ingredient as well as alternative human food. With low cost, DDG and MSG were investigated as a feed ingredient for rearing high quality mealworms. DDG and MSG were mixed with wheat bran and compared to control feed (only wheat bran) for its effects on larval survivorship, larval weight, duration for developmental period, pupation rate, and pupal weight. When DDG added, larval survivorship was reduced to 50~70% compared to the control group. Larvae fed on DDG were heavier from third to sixth week. Especially, larvae with 50% DDG were 28% heavier than the control group at the third week. For the larval period, the 50% DDG group was 11% less than that for the control. The pupal weight for the 30% DDG group was 7% heavier than that for the control group. Pupation rates for all the DDG groups were higher than 90%. When compared to the control, larval survivorship for the 70% MSG group was low, but the 50% and 70% MSG groups were high during the seventh and eighth weeks because of delayed development. After the eighth week, larvae with 70% MSG showed the highest larval weight increase as 9~18% compared to the control group. Except 70% MSG group, all of MSG groups showed more than 90% pupation rates. We confirmed that adding 30~50% of DDG or MSG to conventional wheat bran have a strong potential to replace the conventional wheat bran insect feed for quality insect production.

• 한국패류학회지
• /
• 제26권4호
• /
• pp.303-310
• /
• 2010

개량조개의 인공종묘생산을 위한 유생사육의 최적 사육환경과 먹이생물의 종류에 따른 유생의 성장 및 생존을 조사하였다. 수온에 따른 유생의 성장은 $18^{\circ}C$에서 $33^{\circ}C$까지 수온이 높을수록 빨랐으며, $23^{\circ}C$ 이상에서는 사육 14일째 $230{\mu}m$ 이상 성장하였으나 $18^{\circ}C$에서는 $151.1{\mu}m$로 성장이 부진하였다. 염분별 유생사육 시 염분 30 psu에서 일간 성장은 $11.3{\mu}m$로 가장 빨랐고, 생존율도 65.8%로 가장 높았다. 개량조개 유생은 사육수 1 ml 당 10개체 이하의 밀도에서는 성장과 생존율이 양호하였으나 20개체 이상에서는 다소 성장이 늦어 유생의 사육밀도는 1 ml 당 10개체 이하가 가장 효과적이었다. 개량조개 유생의 빠른 성장과 생존율을 높일 수 있는 유생사육 최적 조건은 수온 $23^{\circ}C$, 염분 30-35 psu, 유생 수용밀도 1-10 개체/ml이었다. 유생사육 시 먹이생물은 미세조류 4종 [Isochrysis galbana, Pavlova lutheri, Isochrysis sp. (green), Chlorella ellipsoidea] 을 혼합 공급한 실험구에서 빠른 성장과 생존율을 높일 수 있으며, 먹이생물을 단일종만을 공급시 I. galbana와 Isochrysis sp. (green) 실험구에서 빠른 성장과 생존율을 높일 수 있었다. 따라서 개량조개 유생의 적정먹이는 I. galbana와 Isochrysis sp. (green)를 포함한 2종 이상을 혼합 공급하는 것이 적합할 것으로 판단된다.

• Animal Systematics, Evolution and Diversity
• /
• 제23권1호
• /
• pp.9-20
• /
• 2007

The complete larval development of Chiromantes haematocheir was obtained by laboratory rearing. Five zoeal and one megalopal stages are described and illustrated in detail. Morphological characteristics of the larvae slightly differ from those of Lee (1988), especially in the setal presence of mouthpart appendages. Seven sesarminid zoeas (Parasesarma acis, Parasesarma pictum, Perisesarma bidens, Sesarmops intermedius, Chiromantes dehaani, Chiromantes haematocheir, and Nanosesarma gordoni) can be distinguished from each other in characters of the carapace spines, the antennal exopod and the fork of telson. A provisional key is first provided to aid the identification of seven sesarminid zoeas in Korea.

• 한국잠사곤충학회지
• /
• 제16권1호
• /
• pp.93-100
• /
• 1974

농약으로 오염된 뽕을 누에에게 급여했을 때 누에의 사육성적과 견질에 미치는 영향을 알아보기 위하여 살충제를 사용하여 실험한 결과 다음과 같은 몇가지 결과를 얻었다. 1. 1,000배액의 살충제를 뽕잎에 살포한 후 25일 자연 방치하였다가 급여하여도 감잠비율이 증가하였다. 2. 농약오염뽕의 누에첨식사육결과 사육성적에 미치는 영향은 살충제별로 차이가 있다. 3. Lebaycid의 첨식구에서는 탈항잠이 출현하였다. 4. 농약오염뽕의 누에첨식사육은 불정형견과 이상견사의 원인이 된다.