• International Journal of Industrial Entomology and Biomaterials
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• 제30권2호
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• pp.45-49
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• 2015

The giant mealworm beetle, Zophobas atratus (Coleoptera: Tenebrionidae), is reared for commercial purposes as a live feed for animals. In 2011, it was officially introduced in Korea, and since then it has been considered commercially important. This beetle is a good animal feed resource because of its high protein content with balanced nutrients. However, its life stage characteristics have not been clearly described, especially of the larval stage that can be used as commercial products. To this end, in our study, we determined the number of Z. atratus larval instars, and described their characteristics at each stage, providing basic information about this beetle. Z. atratus larvae required eight to nine d of incubation period before hatching. The first instar period comprised three to four d. There were relatively large variations in each instar period, except for the first instar. Before the adults emerged, most of the individuals passed through15 to 18 instars. The highest pupation rate, 25.71%, was observed in both 16th and 17th instars. Body length gradually increased with each successive instar and it reached its maximum at the 18th instar. The color of larvae was white at the first instar, and gradually turned brown after the second instar.

• International Journal of Industrial Entomology and Biomaterials
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• 제28권1호
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• pp.5-9
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• 2014

Tenebrio molitor is a major pest of stored grain, although its larvae have potential for use as food. However, little is known about the characteristics of individual larval instars of this species, and the number of instars remains disputed. Therefore, we assessed T. molitor for the average number of instars and its characteristics at different larval stages. The focus of this study was to establish a foundation for further studies on the characteristics of each larval instar. All of the T. molitor larvae showed incubation periods of 7 to 8 d and a period of 3 to 4 d for the $1^{st}$ instar. Beyond the $1^{st}$ instar, there were relatively large variations in the number of days in each instar period. Before emergence, most of the larvae had typically gone through 15 to 17 instars. The highest rate of pupae formation, 28.32%, was observed in the $17^{th}$ instars. The body length gradually increased with each successive instar, reaching its maximum at the 17th instar. Beyond the $17^{th}$ instar, however, the body length decreased. The larvae were white in the first instar, and gradually turned brown after the $2^{nd}$ instar.

• International Journal of Industrial Entomology and Biomaterials
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• 제3권2호
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• pp.157-162
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• 2001

The effect of topical application with naphthoxyacetic acid on economic parameters was analyzed following treatment of fifth instar larvae. Larvae treated during the fifth instar showed significant increase in larval weight along with other enhanced larval, cocoon and adult parameters. The larval period was significantly shortened in all the treated groups with increased cocoon and shell weights in male and shell weight in female in 400 ${\mu}g$/ml treated group and filament length in all the treated groups. Fecundity increased significantly in dose dependent manner in all the treated groups, when compared to that of the carrier control group. This suggests that naphthoxyacetic acid, in addition to affecting larval growth, also affect silk production and reproductive performance.

• Fisheries and Aquatic Sciences
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• 제8권2호
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• pp.90-96
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• 2005

The larvae of Palaemon gravieri were reared in the laboratory at three different temperature regimes ($15^{\circ}C,\;20^{\circ}C,\;and\;25^{\circ}C$) with the salinity ranges (28-32 psu) to understand how temperature and body size influence survival rate, and growth components (molt increment and intermolt period). The optimum temperature for the highest survival rate was $25^{\circ}C$. The intermolt periods consistently increased with an increase in size and instar number; however, the molt increments at successive instars generally decreased with an increase in size and instar number. The shortest intermolt period and the highest larval growth rate both occurred at $25^{\circ}C$. Thus, the optimum temperature for larval survival and growth rate was found to be $25^{\circ}C$ which was the temperature at which the larvae actually appear in nature.

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

• International Journal of Industrial Entomology and Biomaterials
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• 제7권1호
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• pp.75-78
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• 2003

This study was carried out to investigate the mineral content of the feces of the $5^th$ instar larvae in a few silkworm species such as a parent domestic silkworm (Jam134), a hybrid (Kumok-jam), the Japanese oak silkworm, and the Chinese oak silkworm. The major minerals of all silkworms throughout all $5^th$ instar larval period are K, P, Mg and Ca, and the result is consistent with the previous study of the mineral content in the mulberry leaves. Although the calcium content decreased sharply at $7^th$ day of the $5^th$ instar, the crude protein content significantly increased at the same age in both domestic silkworms, suggesting a direct relationship between feeding behavior of the silkworms at the larval period and mineral/protein contents. However, this trend was not observed in both oak silkworms. In the comparison of the mineral content among silkworm species, two domestic silkworms were significantly higher in the calcium content compared with two oak silkworms, and the hybrid Kumok-jam was further higher significantly than the feces of parental Jam 143. Excluding the calcium content, overall no significant content variation in other minerals was observed among four silkworm species studied in this study.

• 한국응용곤충학회지
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• 제34권4호
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• pp.300-307
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• 1995

치자나무의 실생묘포장에서 잎을 식해하는줄녹색박각시의 생활사를 1984년부터 1985년까지 남해에서 조사한 결과를 요약하면 다음과 같다. 줄녹색박각시의 산란기간은 5월 하순부터 26일간이었고, 평균 20.4개의 알을 기주 식물의 잎 뒷면에 산란하였다. 산란후 14일부터 16일 사이에 부화하고, 부화율은 97.6%였다. 알은 타원형이고, 크기는 지름이 1.01mm 길이가 1.14 mm이고 난기간은 14.6일이다. 유충의 평균 길이는 1령이 $3.52\pm$1.01 mm, 2령이 $6.46\pm$0.45mm, 3령이 $13.19\pm$4.27mm, 4령이 $24.08\pm$2.22mm, 5령이 $43.71\pm$5.62 mm이고, 유충의 평균체중은 1령이 $13.34\pm$2.41mg, 2령이 $29.83\pm$6.88mg, 3령이 $76.64\pm$31.31mg, 4령이 $292.09\pm$107.70mg, 5령이 $2,144.84\pm$760.70mg이다. 유충기간은 7월부터 10월까지로 1령이, 12일, 2령이 36일, 3령이 32일, 4령이 16일, 5령이 20일로 총유충기간은 116일이었고, 유충기간 동안에 1마리의 유충이 실생묘 17.18주를 가해하였다. 제5령 유웅이 종령유충으로 평균 15 mm 땅속에 들어가 토립으로 집을 짓고, 그 속에서 번데기가 되어 월동하며, 번데기의 평균 길이는 33.6mm이고, 평균 체중은 2,032mg이다. 성충은 이듬해 5월 중순에서 하순까지 우화하는데, 성충의 성비는 암컷이 42.82%이고, 체색형의 비는 갈색형이 89.93%였다.

• 한국잠사곤충학회지
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• 제4권
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• pp.69-78
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• 1965

1. 치잠기에 있어서 녹강균 Spicaria pracina의 잠복기는 1령기에 8시간, 2령기에 11시간, 3령기에 12일간으로 각각 계속하였다. 2. 치잠기와 장잠기에 있어서 균액의 농도가 짙으면 짙을수록 1령기를 제외하고는 전부 농병이 격심하였다. 3. 특히 장잠기에 있어서 농잠의 잔사율은 경화병잠의 잔사율보다 컸으며 5령에 가까울수록 그 피해는 격심했다. 4. 동광화학공업주식회사제품 Cerisan 석탄 5％가 경화병에 대해서 가장 경제적 효과를 보였으나 20.1％의 해를 갖고 있다.

• 한국응용곤충학회지
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• 제32권2호
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• pp.134-138
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• 1993

파에서 파밤나방 유충의 시기별 공간분포 양식을 충남 아산군 인주면 파 재배 단지에서 조사하였다. 유충의 발생 최성기는 8월 중순과 9월 중하순으로 2회였고 유충의 공간분포 양식은 2가지 형으로 10월의 임의 분포를 제외하고는 모두 집중 분포를 하고 있었다. 유충의 영기별로 공간 분포 양식을 분석한 결과 각 영기 모두 집중분포를 하고 있었고 집중도는 영기가 낮을수록 높았다. 전남 광주와 무안 지방에서 기주 식물별로 파밤나방 유충의 공간 분포 양식을 조사한 결과 발생량이 많았던 고추, 대파 및 주기주 작물인 쪽파, 배추 무 등에서는 집중 분포를 하였고 녹두, 팥, 땅콩, 상치, 호박, 국화, 콩, 개비름 등 발생량이 적었던 작물에서는 임의 분포를 하였다.

• International Journal of Industrial Entomology and Biomaterials
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• 제19권2호
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• pp.243-248
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• 2009

The Larval critical weight is the minimal mass at which further growth in not necessary for a normal time course to pupation. Larval critical weight (Lcw), pupal critical weight (Pcw) and adult critical weight (Acw) of different breeds of Bombyx mori L. were determined through starvation (food deprivation). The Lcw was found to be about 938.46, 2397.26, 2283.57 and 2220.97 mg in males and 1118.15, 2681.04, 2604.9 and 2455.88 mg in females of the multivoltine breed (Nistari), Bivoltine breeds (P5 & NB18) and their hybrid (P5$\times$NB18) respectively. Bivoltine breed P5 took more time (3.35 days) followed by NB18 (3.13 days) & P5$\times$NB18 (3.02 days) to attain larval critical weight (In $5^{th}$ Instar) than the multivoltine breed Nistari (2.42 days). Decrease in weight from larval maximal weight to pupal weight and to adult weight was also observed more in multivoltine than bivoltines, which may be due to more latent feeding period in bivoltines. Since Lcw is a stable character and independent of environment, it could be utilized for characterization of silkworm breeds to assess the quality of an insect.