• The Korean Journal of Zoology
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• v.38 no.3
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• pp.348-355
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• 1995

This Investigation was carried out to map the morphological development of serotonin-immunoreactive neurons in the larval brain of the cabbage butterfly, Artogeia rapae, during five larval stages. Both the first instar larva and the second instar larva contained twenty serotonin-immunoreactive (5-HTi) neurons in each brain. The fibres of 5-HTI commissure was interconnected to two cerebral hemispheres in both brains. However, the 5-HTi commissural fibres was Increased in number in the second-instar larva brain. In the brain of the second Insar larva these 5-HTi fibres formed rich arborization in contralateral neuropils, especially In the posterior parts of it. The third-Instar larva braIn, which Included twenty two 5-HTi neurons, had three groups of 5-HTi commissural fibres. In the fourth Instar larva, the number of 5-HTi fibres as well as 5-HTi cell bodies increased in the brain. The fifth-instar larva brain, which contained fifty four 5-HTi cell bodies, showed the largest number of 5-HTi cell bodies In developing larval brains. The 5-HTi fibres formed richest commissural fibres and some of them run parallel to anteroposterior axis.

• Journal of Sericultural and Entomological Science
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• v.39 no.2
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• pp.174-179
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• 1997

The larval head capsule width, larval weight and length of mulberry longicorn beetle, Apriona germari Hope were measured when the larvae were exuviated in artificial diet rearing. The larval head capsule width from the 1st to the 12th instar was ranged from 0.12 to 0.69 cm, and growth ratio of each instar was significantly high between the 1st and the 2nd instars. The fitness to Dyar's law for the larval head capsule width was 87.6%. When the logarithum of the larval head capsule width is plotted against the number of instars, the calculated regression line was LogY=0.12086+0.06998X and Dyar's constant was 1.18. The larval weight was increased with larval developmental stages, and the coefficient of variation of larval weight was apparently high. But the calculated regression line was LogY=-0.91592+0.25959X and Dyar's constant was 1.25. The growth ration of the larval length was clearly high between the 2nd and the 3rd instars, and that of larvae from the 4th instar was decreased. The calculated regression line was LogY=-0.16932+0.09841X and Dyar's constant was 1.25. In conclusion, our results suggested that the larvae growth of mulberry longicorn beetle appeared to be highly related in the larval head capsule width, larval weight and length.

• International Journal of Industrial Entomology and Biomaterials
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• v.28 no.1
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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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• v.40 no.2
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• pp.41-50
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• 2020

Vermicompost, manure, compost and organic fertilization are ecofriendly. Nowadays, many products resulted from sericulture consumed by humans such as mulberry leaves, fruits, mulberry tea, silk and natural silk cosmetics. Soil applications of three treatments with vermicompost (0.5, 1 and 2 tons per 0.42 hectare) and recommended rate of mineral fertilizers of nitrogen phosphorus potassium were used for investigation. Impact of fertilization on mulberry plant traits of moisture, number of shoots/tree, total shoots length/tree, number of leaves/shoot, number of leaves/ (100g), leaf yield/tree and leaf yield of fadden/season were recorded. In addition the effect of fertilization on larval and cocoon characters of young instar duration, fifth instar duration, total larval duration, larval mortality percentage, weight of third instar larvae, weight of fourth instar larvae, weight of fifth instar larvae, fresh cocoon weight, fresh shell weight, pupae weight, cocoon shell ratio, silk productivity, cocooning percentage, pupation ratio, number of cocoons/ liter, crop cocoons by number, crop cocoons by weight, fecundity and fertility. Using vermicompost treatment was enhancing plant characters. Treatments of V₃, V₂ and V₁ were shortage young, fifth and larvae durations. Mostly feeding silkworm during the whole larval duration on treated mulberry leaves with vermicompost improving the traits average. Using vermicompost for fertilization by rate of V₃ and V₂ is better than others for cocoon characters for females and males.V₃ and V₂ of vermicompost per 0.42 hectare is recommended for rearing mulberry silkworm instead of mineral fertilization.

• 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.

• International Journal of Industrial Entomology and Biomaterials
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• v.30 no.2
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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.

• The Korean Journal of Zoology
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• v.33 no.3
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• pp.330-336
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• 1990

Changes in esterase activity and zymogram pattern during development in Pieirs rapae L. were investigated and three esterases (E2, E6 and E11) from the late 5th instar larvae were purified. Esterase activity in whole body increased rapidly during 5th instar larval stages and reached a peak at the late 5th instar larval stage. The number and intensity of esterase band from whole body and midgut also showed a peak at the late 5th instar larval stage. Purification of esterase was performed using gel filtration on Sephadex G-lOO, ion-exchange chromatography on DEAE-trisacryl and preparative electrophoresis. The final purities of these enzymes were about 30 to 60-fold.

• Korean journal of applied entomology
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• v.5_6
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• pp.27-32
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• 1968

The larval instar of Scintillatrix djingischani OBENBERGER WES determined by measuring the head width of the larvae, some of which were bred in the room and the other collected in orchards during four years(1963-1966). Their growth ratio and variation were also studied. 1) The variation curve of the head width of the Iarvae distinctly appeared to be seven (7) curves, which seemed to have lived to be over seven(7) instars after six(6) times of molting. 2) In general, tile larvae live out to be 6-7 instar. Those pupated at 6th instar seem to over winter in tissue from November as matured. And those pupated in late Spring or early Summer after over wintering in canbium seem to be at 7th instar. 3) The standard deviation of the head width tends to grow larger except at 1st and 7th instar, while the coefficient of variation tends to decrease according as the number of instar increases. The growth ratio was found to decrease according as the number of instar increase except at 1 at and 2 nd instar. 4) To the growth of tee larval head width of this insect, Games and Campbell's formula was more applicable than Dyar's. 5) From the activties of larvae it is presumed that those bred in the year over winter in phelloderm or canbium at the 2 nd-3 rd instar, and the matured (2 year old) emerge the next year after over wintering in cambium or tissue at the 5th or 6th instar.

• Journal of Sericultural and Entomological Science
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• v.41 no.2
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• pp.75-81
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• 1999

The storage protein-like protein has been purified from the 5th instar larval haemolymph of the Chinese osk silkwom, Antheraea pernyi, and the preparation was shown to be homogeneous by 7.5% native-PAGE. The molecule was consisted of a single subunit with a molecular weight of 80K, but the number of the subunits was not determined. The protein was defied as glycoprotein by Schiff's regent stining. Rabbit antibody prepared against the purified protein crotein crossreacted with the 5th instar larval haemolymph proteins of Antheraea pernyi and antheraea yamamai, but not with those of Bombyx mori and Bombyx mandarina.

• Fisheries and Aquatic Sciences
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• v.8 no.2
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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.