• The Korean Journal of Zoology
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• v.3 no.2
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• pp.1-4
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• 1960

Urticating spicules and poison -secreting cells of the last instar larva in Euproctis flava BREMER was studied histologically. Three kinds of cells in the epidermis of tubercles on the lst to 8th abodominal segments are classified according to the arrangement of their nuclei : smallepidermal cells, large gland cells, and elongated trichogen cells. As a result of Mallory's triple straining , the epicuticle , the papila-like structure apart form the tubules inside which are gathered at the base and connected with a middle layer cell through a canal in the cuticle, and the peripheral of the urticating spcicule are yellow. However, the inside of the spicule , the tubules within the papilla-like structure, the canal in the cuticle , nuclei in the pidermal cells and the thin exocuticle are red although the thich endocuticle is blue. Particularly , the large nuclei in the middle layer cells are bright red, the cytoplasms of which are little and stained red, too, and the inside of the spicules apt to be stained red when they are broken. The contents therefore seem to be continuous between the spicules and the large cells. Presumably , the large cell at the middle layer is not te tormogen cell which Tsutsumi (1958) has described , but the gland cell which secretes the poison-substance into spicules as Pawlowsky and Stein 91927) and Tonkes (1933) pointed out. Whether the pisonous substance is secreted from the gland cell into the cytoplasmic processes of the trichogen cells which stick large middle layer cells during the formation of the new spicule as Tsutsumi (1958) has observed, or the gland cell makes a new connection with the spicule after the spicule is formed is not clear.

• Applied Microscopy
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• v.34 no.3
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• pp.199-209
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• 2004

The migut epitheluim of the last instar larva in the mosquito larvae, Anopheles sinensis was observed with electron microscopes. The midgut epitheluim of the mosquito larva is composed of a single-layered columnar absorptive cells, regenerative cells and secretory granular cells. The free surface of the columnar absorptive cells has a regular array of microvilli 'brush border', while cell membranes close to the basal lamina are extrmely infolded and a lot of mitochondria are concentrated in those processes. The columnar absorptive cells also contain cell organelles expected to be found in absorptive cell. Midgut regenerative cells which are positioned basally in the epithelium form the groups, which are called 'nidi', composed of 1 or $2{\sim}3$ cells, they show darker appearance than the columnar absoptive cells. The secretory granular cells contain numerous electron dense granules, $200{\sim}400$ nm in diameter. The cone shaped secretory granular cells are located in the basal portion of the midgut epitheluim. The epithelium is surrounded by the subepithelial space and muscle bundles. The subepithelial space, which is filled with fibrous connective tissue, is innervated by many axon cells and tracheoles.

• International Journal of Industrial Entomology and Biomaterials
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• v.2 no.2
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• pp.161-166
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• 2001

The storage proteins of the mulberry longicorn beetle, Apriona germari Hope, were purified and characterized. Three kinds of storage protein (SP1, SP2 and Sp3) were purified from the last instar larval hemolymph of A. germari by the FPLC techniques, anion exchange chromatography and gel permeation chromatography. The SP1, SP2 and SP3 have a native molecular weight of 480, 440 and 420 kDa, respectively. In the SDS-polyacrylamide gel electrophoresis analysis, these storage proteins are composed of a single protein subunit with molecular weight of 90, 85 and 80 kDa, respectively. This result showed that the storage proteins are hexameric protein. The SP1 and SP2 were stained with Schiffs reagent, but SP3 was not stained. It can be assumed that SP1 and SP2 are glycoprotein. Western blot analyses using the each of polyclonal antiserum against purified SP1, SP2 and SP3 showed that the three antibodies reacted with the each of SP bands, respectively. Also, antibodies against SP1 and SP3 cross-reacted with the SP3 and SP1, respectively. However, SP2 was not cross-reacted with these two antibodies. Also, antiserum against SP2 did not cross-reacted with the SP1 and SP3.

• Applied Microscopy
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• v.35 no.3
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• pp.177-186
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• 2005

The foregut epithelium of the last instar larva in the scarab beetle, Allomyrina dichotoma was observed with electron microscopes. The foregut epithelium of the scarab beetle larva is composed of a single-layered squamous absorptive cell. The luminal surface of the epithelium is covered with cuticular intima. The free surface of the squamous cell has a irregular array of microvilli 'brush border', while cell membrans close to the basal lamina are infolded and a lot of mitochondria are concentrated in those processes. The cytoplasm in the epithelial cells is well developed nucleus, mitochondria. And the basal region of cell contains large lipid-, protein droplets and numerous glycogen granules. The basal lamina is located between the basal membrane and muscle bundle, providing barrier between the epithelium and the hemolymph. The epithelium is surround by the subepithelial space and muscles. The subepithelial space, which is composed of fibrous connective tissue is innervated by many tracheoles and axon.

• The Korean Journal of Zoology
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• v.16 no.1
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• pp.25-41
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• 1973

Ultrastructural changes in the cells of the corpora allata of the pine moth, Dendrolimus spectabilis Butler, were studied by electron microscope to know the structural correlates of hormone production by the gland during the larval-pupal-adult transformations. Mitochondria are in active phases from the overwintered to the last instar larvae and from the pupae just after pupation to the 20-day old pupae, while they are in inactive phases from the making cocoon stage to the prepupae just before pupation. The peripheral allatum cells have electron dense granules in the intracellular vacuoles of smooth-surfaced endoplasmic reticulum in the larval life, particularly in the overwintered larvae and in the early adults but the swollen smooth-surfaced intracytoplasmic vacuoles made by expansion of an end of the tubular rough endoplasmic reticulum, some of which contain fibrous proteins, are observed in addition to the vacuoles in the intercellular spaces in which the vacuoles grow by fusing each other from the mature larvae to the prepupae, both of them disappearing during just before pupation. After pupation the cytolasmic vacuoles develop again in the allatum cells so that they seem to begin the secretory activity. The fact that the neurosecretory granules stored within the axons terminated in the corpus allatum are visible only from the 20-day old pupa about two days before abult emergence to the 5-day old adult means that the secretion from the allatum cells is under the control of the brain from the late pupal stage, while the secretion during from the larval to the early pupal life has no relation with the brain, because such granules are not observed within the axons. It is, therefore, suggested that at least two kinds of hormone are released with the ages as far as concerned with the production and secretion mechanisms of the allatum hormone: juvenile hormone is released until the last instar larvae without any direct stimlation of the brain and gonadotropic hormone is secreted from the late pupa to the adult by getting brain's stimulation and that the secretory phases observed from the mature larvae to prepupae are presumably concerned with the biosynthesis of protein owing to the ecdysone and those from the early pupal stage in uncontrolled condition of the brain with the prothoracotropic activity.

• Korean journal of applied entomology
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• v.61 no.4
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• pp.555-562
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• 2022

We raised the white-spotted flower chafer, Protaetia brevitarsis seulensis, from the larvae stage using a fermented mulberry sawdust-base diet at 25℃ and 16:8 h light:dark photoperiod. First, we determined the optimal density of the neonate larvae to be introduced into a rearing box (543 × 363 × 188 mm). The survival rates of the larvae were higher than 80% at 90 days after rearing at 100-175 larval densities but reduced by more than 10% at 200 larval density. The larval weights at 100 to 150 larval densities were similar; however, the weights at 175 and 200 larval densities were lower than those at 100 larval densities, indicating that the rate of weight gain increased under lower density. Based on these results, we inferred that 100-150 larvae was the optimal density. Second, we investigated the storage conditions of the last instar larvae under low temperatures. Four weight groups (1.8-2.0, 2.0-2.3, 2.3-2.5, and 2.5 g) of larvae were stored at 4, 8, and 10℃, respectively. All the larvae at 4℃ died 70 days after storage, whereas 80% of the larvae survived at 8℃ 70 days after storage, indicating that high larval weight was associated with high survival rates. The adults that emerged from larvae with more than 2.3 g and stored for up to 50 days at 4℃ laid few eggs. However, the adults that emerged from all larval weight groups stored for 70 days at 8℃ and 10℃ laid several eggs successfully. Based on these results, we inferred that the last instar larvae with more than 2.3 g could be stored for 30-50 days at 8℃.

• Korean journal of applied entomology
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• v.62 no.4
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• pp.227-243
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• 2023

The Asiatic pink stem borer, Sesamia inferens (Walker, 1856) (Lepidoptera: Noctuidae) is a pest that attacks rice stems. In this study, we estimated the annual generation of insect in several regions of the Republic of Korea. Adult trapping using a sex pheromone trap detected the occurrence of S. inferens adults in the three northernmost areas around 38° latitude and showed that the insect inhabits all of Korea. In most areas investigated, the seasons of the adult generations estimated using the single-sine degree-day model did not deviate from the corresponding observed seasons of adult occurrence. We estimated that the overwintering larvae hypothetically-estimated using the model could be originated from the last generation of adults. When larvae collected in paddy fields during the autumn season in a few middle and southern areas were reared at 25℃, ca. 70% of pupae did not show additional larval molting before their pupation. All larvae collected in early March in a southern area (Goseong, Gyeongsangnam-do) pupated without additional larval molting when reared at 25℃. Based on these results, we presumed that S. inferens could overwinter as mainly the last instar larval stage in the area. Taken together, we conclude that S. inferens primarily has two generations per year in areas around 38° latitude, and three generations in the areas between 35.3° and 37.3° latitude. In addition, approximately 35% of insects captured by the sex pheromone trap were species other than S. inferens, as determined by analyzing the nucleotide sequences of the cytochrome c oxidase 1 gene. These species were not morphologically misidentified as S. inferens.

• Korean journal of applied entomology
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• v.49 no.1
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• pp.61-67
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• 2010

Effect of inoculation level on pathogenicity, development, and propagation of entomopathogenic nematode, Steinernema arenarium was investigated using the last instar of great wax moth, Galleria mellonella. Pathogenicity of S. arenarium was higher with increasing inoculation level representing 82% at the rate of 5 infective juveniles (IJs) while >98% at the rate of >10 IJs. The number of IJs penetrated into the host was 2.7, 5.0, 7.4, and 12.2 at the rate of 5, 10, 20, and 40 IJs, respectively while 24.3 at the rate of 80 IJs and 40.2 at the rate of 160 IJs. Inoculation level did not affect female adult size (4,616 to 6,444 ${\mu}m$) while affected male adult size (1,600 to 1,934 ${\mu}m$). The rate of stunted female adults was 70.2% at the inoculation level of 80 IJs and 63.7% at the inoculation level of 160 IJs. The number of progenies was 20,431, 26,696, 47,943, 50,516, 58,701, and 74,235 at the rate of 5, 10, 20, 40, 80, and 160 IJs, respectively. The body lengths of IJs were different depending on inoculation level ranging from 636 to 1,496 ${\mu}m$.

• Journal of Life Science
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• v.27 no.6
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• pp.702-707
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• 2017

Insects and their extract have been traditionally used as medicinal resources in Asia. Recently, Gryllus bimaculatus and the larva of Tenebrio molitor, Protaetia brevitarsis, and Allomyrina dichotoma were enlisted as general food ingredients by Korean Ministry of Food and Drug Safety. As the interest in these insects is growing, the detailed investigation is needed for the standardization of suitable and safe rearing techniques. This survey was conducted via personal interviews about edible insect rearing farms in Korea. The basic feed is fermented oak sawdust for P. brevitarsis and A. dichotoma and wheat bran for T. molitor. The various feed additives are blended with each farm's own recipes. The overall growth condition, including sawdust fermentation method, feeding period, and rearing density, varies among the investigated farms. It seems that weight of last instar larva was correlated with the rearing density and duration of the larval period. The heavy metal contents were analyzed after 48 hour starvation and they were very small amount or not detected in investigated insects. We believe that the present data will contribute to develop and standardize the safe rearing techniques of edible insects in Korea.

• Korean journal of applied entomology
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• v.51 no.3
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• pp.223-230
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• 2012

Some high frequency sounds alter physiological processes of the beet armyworm, Spodoptera exigua. This study investigated the effect of ultrasound (${\geq}$ 20 kHz) on larval feeding, pupal development, and adult mating behavior of S. exigua. Ultrasound suppressed feeding behavior of fifth instar larvae, and 30 or 45 kHz treatment inhibited more than 50% of feeding activity. Larvae treated with ultrasound exhibited alterations in major nutrient compositions in the hemolymph plasma. Plasma protein levels decreased with an increase in ultrasound frequency. In contrast, sugar levels increased with an increase in ultrasound frequency. Lipid levels increased with an increase in ultrasound frequency up to 30 kHz and then decreased at treatments > 30 kHz. Hemocytes, the fat body, and epidermis expressed three heat shock proteins and apolipophorin III. Ultrasound treatment markedly inhibited expression of some stress-related genes. Ultrasound treatment also inhibited S. exigua pupal development by extending the pupal developmental period and preventing adult emergence. Last, ultrasound treatment significantly inhibited adult mating behavior, which resulted in a significant decrease in female fecundity. These results show that ultrasound is a physiological stress to S. exigua.